To appreciate why this case has drawn attention, it helps to understand what angiosarcoma actually is. The disease arises from endothelial cells, the flat cells that line the interior surface of blood vessels and lymphatic channels. When these cells turn malignant, they proliferate into wildly disorganized networks of immature, blood-filled channels, solid sheets of atypical cells, or nodular masses that infiltrate surrounding tissue. Angiosarcoma is aggressive by nature, with an early tendency to metastasize to distant organs, and it accounts for only a small fraction of an already uncommon category of cancers. Sarcomas as a whole represent roughly one percent of adult malignancies, and angiosarcomas make up only about two percent of those, which places this tumor among the rarest cancers that oncologists ever confront.

Most cases of cutaneous angiosarcoma do not appear out of nowhere. The two dominant risk factors are chronic lymphedema, the persistent swelling that occurs when lymphatic drainage is blocked, and prior radiotherapy, which can damage vascular tissue in ways that promote malignant transformation years later. Beyond those, researchers have linked angiosarcoma to familial syndromes such as neurofibromatosis and Klippel-Trenaunay syndrome, and to environmental carcinogens including vinyl chloride, thorotrast, arsenic, radium, and androgenic steroids. The tumor shows a predilection for the head and neck, particularly the scalp of elderly men, where sun-damaged skin and abundant superficial vasculature may contribute. When angiosarcoma does strike the male genital system, whether at the base of the penis, the testes, the spermatic cord, or the scrotum, it is a genuine rarity, with only a handful of cases ever documented in the medical literature.

The Egyptian patient’s story began when he arrived at the surgical oncology outpatient clinic after having undergone an excisional biopsy of a scrotal lesion at another facility, where microscopic examination had already suggested angiosarcoma. He had no relevant medical or surgical history, no family history of note, and no occupational or environmental exposure to known carcinogens. On examination, clinicians found a three-centimeter residual ulcer on the right side of his scrotum, along with an atrophic testicle underneath. The absence of every classic risk factor made the diagnosis all the more puzzling, and it prompted the team to conduct a thorough diagnostic workup that combined imaging, histopathology, and immunohistochemistry.

Ultrasound of the scrotum revealed a well-defined, heterogeneous oval mass in the right hemiscrotum measuring 46 by 43 by 38 millimeters, clearly separable from the testicle, which itself appeared normal in size and echogenicity. Post-contrast magnetic resonance imaging added crucial detail: the right testicle was small with an irregular outline and showed signal characteristics consistent with infarction, meaning it had lost its blood supply, while the scrotal wall displayed diffuse thickening and enhancement suggestive of post-operative or inflammatory change. Enlarged right inguinal lymph nodes were also identified, though computed tomography of the chest, abdomen, and pelvis found no evidence of distant metastasis, a critical finding for staging and treatment planning.

The definitive diagnosis, however, rested on the microscope. Pathologists at Mansoura University revised the original biopsy slides and paraffin blocks and found malignant tumor tissue arranged in variable-sized sheets, with multiple vascular spaces lined by large, atypical cells showing moderate nuclear atypia and prominent nucleoli. Wide areas of necrosis were present, and mitotic figures, including atypical forms, were frequent, all hallmarks of a high-grade malignancy. The tumor displayed the classic architectural pattern of angiosarcoma: a proliferation of anastomosing, small, immature blood-filled spaces, with some focal solid areas, lined by plump endothelial cells set in a fibromyxoid stroma.

Immunohistochemistry, the technique that uses antibodies to detect specific proteins in tissue sections, sealed the diagnosis. The tumor cells showed diffuse, strong immunoreactivity for ERG, a transcription factor regarded as a sensitive marker of vascular endothelial differentiation, and focal positivity for CD31, another endothelial marker. The proliferation index, measured by Ki-67 staining, was strikingly high, with 60 to 70 percent of tumor cells staining positive, indicating rapid cell division. Just as important were the negative results: the tumor did not react to stains for cytokeratin, CD34, desmin, S100, smooth muscle actin, or human herpesvirus 8, which helped exclude carcinomas, other sarcoma subtypes, melanoma, and Kaposi sarcoma from consideration. Together, the morphology and immunoprofile confirmed cutaneous angiosarcoma of the scrotum.

Management was decided at a multidisciplinary sarcoma meeting, where the team opted for wide local excision. The patient underwent removal of the right hemiscrotum, including the atrophied right testicle, through a scrotal approach, and was discharged the following day. Post-operative pathology delivered welcome news: no residual tumor tissue was found in the specimen. Over eleven months of follow-up, with regular three-monthly visits involving clinical examination, basic laboratory tests, and chest imaging, the patient has shown no local recurrence and no distant metastasis, an outcome that stands in contrast to the generally dismal prognosis associated with cutaneous angiosarcoma.

The case is remarkable from several angles at once. Scrotal tumors are far more likely to be squamous cell carcinomas than angiosarcomas. Cutaneous angiosarcoma itself rarely presents in the genital skin. De novo angiosarcoma, arising without lymphedema, radiation, or a genetic syndrome, is exceedingly uncommon anywhere in the body. And this patient represents only the fifth reported case of cutaneous scrotal angiosarcoma in the literature, with previous cases having been tied to identifiable factors such as neurofibromatosis or prior radiation therapy for other cancers. The authors speculate that an unknown risk factor, perhaps a genetic predisposition or an environmental exposure not yet recognized, may underlie this tumor, opening a line of inquiry for future research.

The broader lesson for clinical practice is one of vigilance. Scrotal lesions are common in everyday practice and can range from benign cysts and inflammatory conditions to hemangiomas, lymphangiomas, and malignant tumors, so distinguishing benign from malignant disease is paramount for proper treatment. Because cutaneous angiosarcoma follows an aggressive course with early metastatic potential, and because surgery remains the only modality associated with improved survival, according to a large analysis of 764 patients, delayed diagnosis can be fatal. The Mansoura team argues that any suspicious cutaneous manifestation on the scrotum should prompt consideration of angiosarcoma, even in patients with no risk factors whatsoever. They also call for improved diagnostic criteria, standardized treatment protocols, and studies of adjuvant options such as immunotherapy and targeted therapy, along with long-term follow-up research to clarify recurrence patterns and optimize surveillance. For now, this single unusual case serves as a reminder that in oncology, rarity is not the same as impossibility, and that the rarest presentations often teach the most enduring lessons.

Subject of Research: A rare case of primary cutaneous angiosarcoma of the scrotum arising without identifiable risk factors

Article Title: Primary cutaneous scrotal angiosarcoma: a case report and literature review

Article References: Hamdy, O., Ragab, D., Farouk, B., Allam, M. M., Asy, R. A., Saleh, G. A., & Mohamed, M. A. (2024). Primary cutaneous scrotal angiosarcoma: a case report and literature review. Clinical Cancer Bulletin, 3(1), Article 20. https://doi.org/10.1007/s44272-024-00025-9

Image Credits: AI Generated

DOI: 10.1007/s44272-024-00025-9

Keywords: angiosarcoma, scrotal tumor, cutaneous angiosarcoma, case report, immunohistochemistry, ERG, CD31, sarcoma, vascular tumor, surgical oncology, rare cancer, Mansoura University

Now a team of researchers from Meenakshi Medical College Hospital and Research Institute in Tamil Nadu, India, has published a formal commentary in the same journal challenging that interpretation. In a Matters Arising contribution, R. Saravanan, Paramanantham Madhavan, R. Sivayogana, and K. Anusha do not dispute the value of the underlying registry analysis, which they describe as an important framework for evaluating rare cancers using population-level data. Instead, they raise two methodological concerns that, if correct, could substantially alter how the German findings should be read. The first concerns whether the apparent rise in multivisceral resection reflects a real change in surgical practice or simply an improvement in how operations were documented and coded over time. The second concerns the handling of missing data on tumor grade and metastatic status, variables that were absent in a large fraction of cases yet still used to stratify survival analyses. Both concerns strike at the heart of a growing movement in oncology: the use of registry data to draw clinical conclusions about diseases too rare for randomized trials.

The argument about coding is technically subtle but conceptually compelling. The German analysis of organ resections relied on a subset of only 1,318 patients with codeable resection procedures, a considerably smaller group than the full surgical cohort, and it depended entirely on whether the Operationen- und Prozedurenschlüssel, the German procedure coding system, captured a code for every organ removed during each operation. The commentary points out that the original paper itself acknowledged a parallel phenomenon: the rise in annual case numbers over the same period was attributed to improving case ascertainment and documentation completeness following the 2014 legal framework for cancer registration, not to a true increase in disease incidence. If overall case documentation improved across two decades, the Indian authors argue, it is plausible and untested that procedure-level documentation improved as well. Under that scenario, earlier multivisceral resections may have been underdocumented, with only the single most prominent procedure code recorded, while later cases benefited from more complete coding that captured every organ removed in the same operation. Part or all of the observed temporal trend would then reflect better paperwork rather than bolder surgery.

The distinction is far more than methodological tidiness. If the trend is substantially a documentation artifact, the commentary notes, then the implicit message to clinicians and registry stewards, that German surgical practice has progressively converged on international multivisceral resection guidelines for liposarcoma, would be overstated. The more accurate takeaway would concern the maturation of registry coding rather than the maturation of surgical decision-making. The authors propose a concrete diagnostic test: reporting the proportion of surgical cases with at least one codeable resection procedure by diagnosis year, alongside the existing organ-count trend, would allow readers to judge whether the apparent rise in multivisceral resection tracks improving procedure documentation or represents an independent change in clinical practice. If the two curves move together, the documentation explanation gains weight; if they diverge, the practice-change interpretation becomes more credible. Such a check costs nothing beyond additional analysis of data already in hand, which is precisely why the commentary frames its absence as a missed opportunity.

The second major concern involves missing data in the survival analyses. According to the commentary, grading information was missing in twenty-four percent of cases, and distant metastasis status was missing in fifty-five percent, yet both variables were used to stratify the survival analyses and the primary treatment description without any sensitivity analysis addressing whether the missingness was informative. This matters because of a well-known statistical hazard: complete-case analysis, in which patients lacking a given variable are simply excluded, produces unbiased results only if the missing data occur randomly. If, as the original paper’s own discussion suggests, earlier-era cases suffered from less complete documentation, then those cases may be disproportionately represented among patients with missing grading or staging information. The Kaplan-Meier survival curves and treatment-pattern tables restricted to complete cases would then systematically overrepresent more recent, better-documented tumors, which may differ from the excluded cases in surgical approach, tumor biology ascertainment, or case mix. The resulting curves could paint a rosier or otherwise distorted picture of outcomes across the full registry cohort.

The commentary applies this concern specifically to the Kaplan-Meier estimates stratified by grade, which were calculated only among the roughly three-quarters of cases with recorded grading. No comparison of baseline characteristics between graded and ungraded cases was provided to establish that the two groups were otherwise similar. The authors suggest a remedy that mirrors their proposal on procedure coding: reporting whether missingness in grading and metastasis status varies systematically by diagnosis year, and providing a basic comparison of age, sex, and histology distribution between complete and incomplete cases. Such comparisons would allow readers to judge whether the survival and treatment-pattern findings generalize to the full registry cohort or are specific to the more thoroughly documented subset. The commentary also notes an internal inconsistency in the original paper’s logic: the study elsewhere treats improving documentation completeness as a plausible explanation for other temporal patterns in the dataset, yet does not extend that same reasoning to the grading and staging variables underlying the survival analysis.

What makes this exchange notable is its constructive tone and its broader relevance. The Indian authors explicitly state that neither concern displaces the substantial contribution of the German study, which established a reproducible, histology- and location-specific framework for extracting a rare tumor cohort from national registry data. They call that framework a genuinely useful methodological template for future rare-cancer registry research well beyond retroperitoneal sarcoma. The stakes they identify are correspondingly high: distinguishing genuine practice change from improved documentation completeness, and characterizing whether missing data correlate with diagnosis era, would allow clinicians and health-policy readers to rely on reported trends as evidence of evolving surgical practice with greater confidence, rather than treating documentation artifacts as clinical signals. In an era when health systems increasingly mine administrative and registry data to guide cancer care, the commentary is a reminder that the quality of the data pipeline can be as consequential as the quality of the medicine it records.

The technical issues at play are familiar to epidemiologists but deserve wider understanding. Procedure coding systems like the German OPS are designed for billing and administration, not research, and their granularity depends on local coding habits, staffing, and evolving regulations. Studies of complex surgical specimens in other fields have documented substantial variability in how thoroughly multi-organ procedures are captured in coded records, and the commentary cites work on procedural terminology optimization in genitourinary surgery as an illustration. Similarly, the problem of informative missingness in registry-based survival analysis has prompted a growing literature on imputation techniques for Kaplan-Meier estimation, which the commentary references. Neither problem is unique to the German study; both are endemic to registry research. The commentary’s contribution is to show how these general hazards map onto the specific claims of a high-profile national analysis, and to propose analyses that would resolve the ambiguity without requiring new data collection.

For patients with retroperitoneal sarcoma, the practical implications are indirect but real. Multivisceral resection is the single most important determinant of long-term survival in this disease, and international guidelines recommend aggressive compartmental surgery for liposarcoma whenever feasible. If German practice has genuinely converged on those guidelines over two decades, that is encouraging news for the roughly one in a hundred thousand people diagnosed each year. If instead the trend partly reflects coding maturation, the appropriate response is not complacency about surgery but investment in registry quality, so that future analyses can distinguish the two. The commentary, published open access in October 2026, ultimately asks for methodological consistency: the same skepticism about documentation quality that the original authors applied to case counts should be applied to procedure codes, tumor grades, and staging data. Whether the German group responds with the requested sensitivity analyses will determine how confidently the oncology community can cite this study as evidence that surgical practice, and not merely surgical record-keeping, has changed.

Subject of Research: Methodological evaluation of German cancer registry data on retroperitoneal sarcoma treatment trends

Article Title: Comment on “Treatment of retroperitoneal sarcoma in Germany between 2000 and 2022: a retrospective analysis from the German Cancer Registry Group”

Article References: Comment on “Treatment of retroperitoneal sarcoma in Germany between 2000 and 2022: a retrospective analysis from the German Cancer Registry Group”. (n.d.). https://doi.org/10.1007/s00432-026-06591-w

Image Credits: AI Generated

DOI: 10.1007/s00432-026-06591-w

Keywords: retroperitoneal sarcoma, cancer registry, multivisceral resection, registry completeness, missing data, survival analysis, surgical oncology, liposarcoma, rare cancers, clinical epidemiology, procedure coding, Germany

The case began innocuously. The patient developed persistent hoarseness after an upper respiratory infection, and flexible laryngoscopy revealed a tumor arising from the left true vocal fold and extending toward the anterior commissure. Scans showed the mass confined to the glottic and supraglottic regions of the larynx, with no lymph node involvement or spread to distant organs. A biopsy was read as poorly differentiated squamous cell carcinoma, the most common and most familiar cancer of the head and neck. Because the histology looked conventional, and because the patient was initially staged with a potentially curable stage II disease, no test for NUT carcinoma was performed at that time. That decision, the report makes clear, would shape everything that followed.

Given his youth, the clinical team pursued a larynx-preserving strategy. He received induction chemotherapy with docetaxel, cisplatin, and cetuximab, followed by definitive chemoradiotherapy delivering seventy gray of intensity-modulated radiation with concurrent carboplatin and 5-fluorouracil. The primary tumor vanished completely on endoscopy and imaging, and maintenance therapy with the oral agent S-1 followed. For ten months the remission held. Then, in August 20X1, a recurrent lesion appeared at the original site, this time with paralysis of the vocal fold on the same side. Surgeons performed a total laryngectomy, removing the entire voice box, and pathology again showed moderately to poorly differentiated squamous cell carcinoma. The tumor, everyone assumed, had been dealt with.

It had not. Five months after surgery the patient developed painful swallowing, and imaging revealed an ulcerative mass on the posterior pharyngeal wall along with a solitary lesion in the iliac bone of the pelvis. Chemotherapy with cisplatin and docetaxel failed within a single cycle. The immune checkpoint inhibitor nivolumab, which works well in a subset of head and neck cancers, also failed within weeks. Comprehensive genomic profiling using the FoundationOne CDx assay detected no actionable alterations and, crucially, did not detect the BRD4::NUTM1 fusion—a false negative that is well documented for NUTM1 rearrangements, since DNA-based sequencing depends on where the breakpoint falls and how well that region is captured. The tumor’s biomarker profile, with a low tumor mutational burden of four mutations per megabase and a microsatellite-stable genome, offered no foothold for immunotherapy.

The definitive answer came only after a third salvage operation. Radical surgery at Aichi Cancer Center involved circumferential pharyngectomy, removal of the cervical esophagus, and reconstruction with a free segment of jejunum. When yet another recurrence appeared around the permanent tracheostoma five months later, additional immunohistochemistry on the resected tissue revealed diffuse nuclear staining for the NUT protein with a characteristic speckled pattern, alongside expression of the squamous markers p63 and p40. That single stain established the true diagnosis: NUT carcinoma. Retrospective testing of archived specimens using fluorescence in situ hybridization and RNA-based reverse transcription polymerase chain reaction confirmed a BRD4::NUTM1 fusion and proved the tumor had been NUT carcinoma from the very beginning, hidden behind a costume of ordinary squamous cancer.

The biology explains both the disguise and the ferocity. NUT carcinoma is driven by fusion proteins that typically join the tandem bromodomains of BRD4, which latch onto acetylated histones, to the NUT moiety, which recruits the p300/CBP acetyltransferases. The result is enormous hyperacetylated chromatin domains that force MYC expression and lock immature epithelial cells into a perpetual, proliferating, non-differentiating state. Because the cells still express squamous markers such as p63 and p40, pathologists see a plausible squamous cell carcinoma under the microscope. Only diffuse NUT immunostaining or molecular detection of the NUTM1 rearrangement separates the two diseases, and the report argues forcefully that young, non-smoking patients with aggressive, poorly differentiated tumors at midline or head and neck sites should trigger NUT-specific testing early.

With the diagnosis finally in hand, the team tried what mechanistic logic suggested should work. A bromodomain and extra-terminal, or BET, inhibitor—the class of drugs designed precisely to displace BRD4 from acetylated chromatin—was given through a clinical trial. The response was swift and dramatic: imaging at three months showed a marked partial regression. But after roughly six months, new lesions emerged and treatment stopped after eight cycles. Resistance to BET inhibition is thought to arise not through target mutations but through adaptive rewiring, in which tumor cells restore MYC-centered transcriptional programs using compensatory co-regulators such as p300/CBP and histone deacetylases, or bypass signaling through the MAPK/ERK pathway. A trial of the histone deacetylase inhibitor vorinostat, intended to attack that same acetylation circuitry from the opposite direction, produced no control whatsoever, consistent with functional redundancy between HDAC1 and HDAC2.

Even intensive cytotoxic chemotherapy delivered only borrowed time. Alternating cycles of vincristine, doxorubicin, and cyclophosphamide with ifosfamide and etoposide—a regimen borrowed from pediatric sarcoma practice—shrank the tumor markedly after two cycles, a reminder that this highly proliferative cancer retains some sensitivity to DNA-damaging agents. Yet regrowth appeared during the third cycle. Paclitaxel with cetuximab failed twice, and pembrolizumab combined with cisplatin and 5-fluorouracil achieved nothing. By June 20X4 the disease had replaced much of the anterior neck, and care shifted to palliation. Weekly applications of Mohs paste, a zinc chloride-based preparation rarely discussed in modern oncology, were used to harden the tumor surface and control malodorous exudate and bleeding, while morphine managed pain. The patient died in late July with his family present, having lost more than thirty kilograms from his baseline weight.

The autopsy delivered the report’s most consequential insight. Although the lungs were studded with innumerable metastatic nodules, each only a few millimeters across, the immediate cause of death was not disseminated cancer. It was overwhelming infection driven by uncontrolled locoregional disease—a massive twenty-three by twenty centimeter infiltrative tumor occupying the neck, invading the reconstructed jejunum, and compromising the airway, complicated by bilateral cavitary lung abscesses. This distribution matters therapeutically: fatal outcomes in NUT carcinoma may hinge less on distant metastasis than on relentless local progression along the aerodigestive tract, reinforcing evidence from prior series that durable locoregional control with surgery and radiotherapy underpins the only long-term survivals recorded.

The authors place their experience against the eighteen previously documented laryngeal cases, most of which arose in the supraglottis and claimed their victims within a year. Their patient’s glottic origin, four-year course, and autopsy characterization are all firsts for this site, and his survival of more than two years beyond the detection of an iliac bone metastasis stands against registry data showing zero percent two-year survival for metastatic head and neck NUT carcinoma. The broader lesson is uncomfortable but clear: despite its microscopic resemblance to squamous cell carcinoma, this is a transcription-addicted malignancy that standard head and neck regimens—induction chemotherapy, platinum-taxane combinations, and checkpoint inhibitors—all failed to hold in check. Some researchers now argue NUT carcinoma should be regarded as a molecularly defined subtype of squamous carcinoma rather than a separate entity, a framing that would push NUT testing into routine practice. Whether future patients benefit will likely depend on diagnosing the fusion early and combining epigenetic drugs with cytotoxic debulking and definitive local therapy, rather than adding agents one at a time to a network evolution too easily circumvents.

Subject of Research: Diagnosis and treatment resistance in BRD4::NUTM1 fusion laryngeal NUT carcinoma

Article Title: Laryngeal NUT Carcinoma With BRD4::NUTM1 Fusion: A 4‐Year Clinical Course Highlighting the Limitations of Current Multimodal Therapy

Article References: Kanno, M., Sasaki, C., Kato, E., Terada, H., Hanai, N., Sasaki, E., Fukushima, M., Masuishi, T., Takanari, K., Fukada, Y., Miyazaki, Y., Sonoda, Y., Kato, Y., Morikawa, T., Takabayashi, T., & Fujieda, S. (2026). Laryngeal NUT Carcinoma With BRD4 :: NUTM1 Fusion: A 4‐Year Clinical Course Highlighting the Limitations of Current Multimodal Therapy. Cancer Reports, 9(9), Article e70679. https://doi.org/10.1002/cnr2.70679

Image Credits: AI Generated

DOI: 10.1002/cnr2.70679

Keywords: NUT carcinoma, BRD4::NUTM1 fusion, laryngeal cancer, BET inhibitor, vorinostat, squamous cell carcinoma, NUTM1 rearrangement, chemoradiotherapy, immune checkpoint inhibitor, autopsy findings, epigenetic therapy, rare cancer

The patient’s story began in September 2019, when she first noticed a small, mobile mass in her left breast measuring roughly 2 by 1 by 1 centimeters. The lump caused no tenderness, no skin changes, and no nipple discharge, so she initially ignored it. Two months later, at another hospital, mammography and breast color Doppler ultrasound both classified the lesion as Breast Imaging Reporting and Data System category III—a designation implying a probably benign finding with less than a 2 percent risk of malignancy—and recommended routine follow-up. Over the following three months, however, the mass grew dramatically, reaching approximately 4 by 3 by 2 centimeters and occasionally becoming painful. That rapid enlargement prompted her admission to the reporting hospital in March 2020, where physical examination found a smooth, moderately firm, mobile mass without skin ulceration, nipple retraction, or enlarged lymph nodes in the armpits.

The imaging workup revealed a striking contradiction. Mammography at the outside hospital had graded the lesion BI-RADS 3, but repeat ultrasound at the new institution upgraded it to BI-RADS 4A, indicating a small but real suspicion of malignancy of roughly 2 to 10 percent. The ultrasound showed a solid, irregular, lobulated mass at the 11 o’clock position of the left breast, containing strip-like blood flow signals with low-resistance arterial waveforms—a vascular pattern that would later prove telling. Chest computed tomography confirmed a mound-shaped mass in the upper inner quadrant with an unclear boundary on plain scan. Meanwhile, laboratory results were entirely unremarkable: blood counts, liver and kidney function, and coagulation were normal, and the tumor markers CEA, CA 15-3, CA 125, and CA 19-9 all sat comfortably within reference ranges. The team noted that breast angiosarcomas frequently produce negative results on routine malignant tumor markers, rendering these tests of extremely low diagnostic value in such cases.

Reconciling the discordant imaging grades against current standards proved decisive in shaping the diagnostic pathway. According to the fifth edition of the American College of Radiology BI-RADS criteria, the 2024 National Comprehensive Cancer Network breast guidelines, and the 2021 Chinese Society of Breast Surgery fibroadenoma guideline, the combined clinical and imaging picture did not meet formal indications for contrast-enhanced breast MRI, bone scintigraphy, or percutaneous core needle biopsy. Those tools are reserved for high-risk patients, radiologically indeterminate lesions with definite malignant suspicion, or preoperative staging of confirmed cancers—not for discordant low-grade BI-RADS 4A lesions accompanied by benign mammographic findings. The clinicians therefore concluded the lesion was highly suggestive of a benign fibroadenoma and recommended elective surgical resection, a decision that conformed to guidelines but, as they later acknowledged, failed to account specifically for the lesion’s rapid growth.

Surgery took place on March 11, 2020, under general anesthesia, and it was here that the case pivoted. Intraoperative frozen section pathology suggested a spindle cell tumor tending toward a vascular origin, with definitive classification awaiting immunohistochemistry. Because the team had rarely encountered such lesions, and because committing to a radical operation on an uncertain diagnosis carried obvious risks, they consulted the patient’s family and made the unusual decision to temporarily suspend the surgery. Final pathology returned on March 17: the excised nodule, about 3.5 by 2.5 by 1.8 centimeters, was packed with anastomosing slit-like vascular channels infiltrating breast lobules and fat, lined by a single layer of endothelial cells showing mild nuclear atypia and occasional mitoses. Immunohistochemistry showed strong positivity for the endothelial markers CD34, CD31, and FLT-1, along with vimentin and smooth muscle actin, while epithelial markers EMA and broad-spectrum cytokeratins were negative. The Ki-67 proliferation index was 25 percent. The diagnosis was low-grade angiosarcoma.

To be certain, the slides were sent for outside consultation at a higher-level hospital, which returned on March 20 with a confirmatory and slightly more concerning picture: part of the tumor showed the mild, well-formed vascular pattern, but other areas were solid, densely cellular, and pleomorphic with mitotic figures, extensive hemorrhage, and necrosis. The consultants recommended optional molecular testing for c-Myc, KDR, and VEGFR2—markers mainly useful for distinguishing primary from radiation-associated secondary angiosarcoma—though the team ultimately judged these unnecessary given the clear histopathological diagnosis. After a hospital-wide multidisciplinary team discussion, the patient underwent completion resection of the remaining left breast tissue plus sentinel lymph node biopsy on March 23. Frozen section confirmed an R0 resection with clear microscopic margins and no sentinel node metastasis, and final pathology found no residual cancer in the surrounding breast, nipple, skin, or basal margin, with zero of three sentinel nodes involved.

The staging and treatment decisions reflected the peculiar biology of this tumor. Under the eighth edition of the AJCC staging system, the disease was classified as stage I (T1N0M0). Unlike conventional breast carcinoma, which spreads chiefly through lymphatic channels, primary breast angiosarcoma metastasizes predominantly through the bloodstream, seeding the liver, lungs, bone, and brain early, while regional lymph node involvement is extremely rare. Routine axillary lymph node dissection is therefore not recommended, and the team performed only a sentinel node biopsy for accurate staging, sparing the patient unnecessary surgical trauma. Beginning April 3, 2020, she received eight cycles of adjuvant chemotherapy—four of doxorubicin plus cyclophosphamide followed by four of paclitaxel—completed without significant adverse reactions by the end of July 2020.

The prognosis data assembled in the report underscore why vigilance matters. Secondary angiosarcoma of the breast, which typically arises after radiotherapy for breast cancer or in the setting of chronic lymphedema known as Stewart-Treves syndrome, carries a five-year overall survival of roughly 38 percent with a recurrence-free survival of about 43 months. Primary breast angiosarcoma fares somewhat better, with a five-year overall survival near 49 percent and recurrence-free survival of about 44 months, with outcomes tied to stage, histological grade, and tumor size. Diagnosis remains the hardest part: mammography yields false negatives in roughly a third of patients because of dense glandular tissue, ultrasound lacks specificity despite showing heterogeneous masses and increased blood flow, and MRI—considered the most useful non-invasive modality—reveals heterogeneous signals and avid contrast enhancement reflecting the tumor’s rich vascularity. Core needle biopsy, the usual route to preoperative diagnosis, frequently returns false negatives because of bleeding risk and marked tumor heterogeneity, meaning most cases are only confirmed after surgery.

Emerging evidence is beginning to reshape treatment thinking for this orphan disease. A meta-analysis by Skarentzos and colleagues found that adjuvant chemotherapy significantly improved survival in primary breast angiosarcoma, with a hazard ratio of 0.11, while radiotherapy showed no survival benefit. Anthracycline-, ifosfamide-, and paclitaxel-containing regimens are considered the most effective, though the disease’s rarity means evidence rests on small series and case reports rather than large trials. Genomic research is opening new doors: the Angiosarcoma Project, a patient-partnered genomic study, has suggested that inhibitors of the phosphatidylinositol-3-kinase catalytic alpha subunit could become targeted therapeutic options, and next-generation sequencing may eventually identify actionable alterations in tumors like this one.

Follow-up tells the story’s encouraging end. The patient was re-examined at one, three, and six months after surgery, then roughly every six months, with breast ultrasound, chest CT, abdominal and urinary tract ultrasound, blood counts, and tumor markers. As of November 5, 2025—more than five years after her diagnosis—she showed no sign of local recurrence or distant metastasis. The authors argue their case carries three broader lessons: that a rapidly growing, benign-appearing breast mass in a postmenopausal woman deserves heightened suspicion even when guidelines do not mandate advanced imaging; that suspending surgery when frozen section reveals something unexpected can preserve diagnostic accuracy and prevent undertreatment; and that multidisciplinary collaboration, staged surgery, and guideline-conformant individualized therapy can deliver excellent long-term outcomes even in a cancer this rare and this easy to miss.

Subject of Research: Primary breast angiosarcoma diagnosis and treatment in a postmenopausal woman

Article Title: Primary Mammary Angiosarcoma in a Postmenopausal Woman: A Case Report

Article References: Liu, T., Xu, Y., Wang, Q., Yu, S., Lin, H., Ye, Z., Zheng, Z., Yang, C., & Hong, T. (2026). Primary Mammary Angiosarcoma in a Postmenopausal Woman: A Case Report. Cancer Reports, 9(9), Article e70653. https://doi.org/10.1002/cnr2.70653

Image Credits: AI Generated

DOI: 10.1002/cnr2.70653

Keywords: breast angiosarcoma, primary breast angiosarcoma, postmenopausal, BI-RADS, fibroadenoma, frozen section pathology, immunohistochemistry, CD31, sentinel lymph node biopsy, adjuvant chemotherapy, R0 resection, rare cancer