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