The mass was ultimately identified as a T-lymphoblastic lymphoma, an aggressive cancer of immature T-cell lymphocytes that often announces itself as a rapidly enlarging mediastinal tumor. Lymphomas of this type are notorious among diagnosticians because they demand not just a sample of tissue but a well-preserved one. Pathologists need to see the architecture of the tissue, the shape of the cells, and the results of an entire panel of immunohistochemical stains, each of which reveals whether the malignant cells carry particular protein markers. A crushed or blood-soaked fragment of tumor can render all of that analysis impossible, forcing patients into more invasive surgery or delaying treatment of a fast-moving disease.

For decades, the gold standard for sampling mediastinal tumors was mediastinoscopy, a surgical procedure in which a camera is inserted through an incision above the breastbone to reach the space between the lungs. It provides generous tissue samples, but it requires general anesthesia in a operating room, leaves a scar, and carries the risks of any surgical approach to a crowded anatomical neighborhood. Endobronchial ultrasound-guided transbronchial needle aspiration, known as EBUS-TBNA, changed that calculus. In this minimally invasive technique, a bronchoscope equipped with an ultrasound probe at its tip is passed through the windpipe, allowing the physician to see lymph nodes and masses through the airway wall and to pierce them with a fine needle. EBUS-TBNA has become the standard first-line tool for staging lung cancer and sampling mediastinal lesions, with high accuracy for detecting metastatic disease in lymph nodes.

But lymphoma is where the needle technique hits its limits. The tiny cores of tissue obtained through a 22-gauge needle are often fragmented and distorted by crush artefact, the mechanical damage inflicted as the needle cuts through delicate lymphoid cells. Add blood contamination, and the pathologist may receive a specimen too poor to distinguish between the many subtypes of lymphoma or to rule out other malignancies. That is precisely what happened in this case. When the medical team performed EBUS-TBNA three times at the same site using a 22-gauge needle, the resulting specimen failed to yield definitive findings. The tissue was crushed and blood-stained, and the diagnosis remained out of reach.

The team then turned to a newer approach that has been generating enthusiasm in interventional pulmonology: endobronchial ultrasound-guided transbronchial mediastinal cryobiopsy, or EBUS-Cryo. Cryobiopsy exploits one of the simplest physical effects in medicine, the fact that moisture instantly freezes and bonds to a very cold metal surface. Instead of cutting tissue with a blade or tearing it with forceps, the physician touches a cryoprobe cooled to extreme subzero temperatures against the target tissue for a few seconds. The tissue freezes onto the probe and is pulled away en bloc, retaining its cellular architecture far better than tissue harvested by cutting instruments. The technique has already shown promise in diagnosing pulmonary lymphomas and other lymphoproliferative disorders, and its extension into mediastinal sampling through the EBUS working channel represents a significant technical advance.

In this case, the procedure was performed under endotracheal intubation with an 8.5-millimeter tube, which secured the airway throughout. First, the EBUS-TBNA needle was used to create a tract through the airway wall into the mass. Then a 1.1-millimeter cryoprobe was threaded through that same tract and advanced under EBUS guidance into the tumor. The probe tip was frozen for seven seconds, after which the cryoprobe was withdrawn together with the bronchoscope as a single unit, bringing the frozen specimen with it. This maneuver was repeated until six cryobiopsy specimens had been collected. Notably, rapid on-site cytologic evaluation was not used, yet the samples proved diagnostically decisive. The entire examination proceeded without hypoxemia, bleeding, or any other adverse event, and the patient went home the very next day.

The pathological comparison between the two sampling methods was striking. The needle aspiration specimens were non-diagnostic, whereas the cryobiopsy material showed beautifully preserved tissue structure, with diffuse proliferation of atypical lymphocytes bearing round nuclei and a high nucleus-to-cytoplasm ratio. Immunohistochemical staining then told the full story. The atypical cells were positive for CD3, CD2, CD7, and CD99, a profile pointing firmly toward a T-cell lineage. They were negative for CD20, which argued against a B-cell lymphoma, and negative for AE1/AE3, which excluded an epithelial cancer such as thymoma or carcinoma. Markers including CD4, CD5, CD8, CD1a, CD34, c-kit, and SALL4 were also absent, narrowing the differential diagnosis further. Terminal deoxynucleotidyl transferase, or TdT, a hallmark of immature lymphoblasts, was expressed in only a small subset of cells, an atypical feature for T-lymphoblastic lymphoma. Weighing the full histopathological and immunophenotypic picture alongside the patient’s young age and the anterior mediastinal location of the tumor, the team arrived at a definitive diagnosis of T-lymphoblastic lymphoma, and she was referred promptly to hematology for systemic chemotherapy.

Safety deserves particular emphasis, because this case involved an unusually hazardous starting point. Mediastinal cryobiopsy, while generally considered relatively safe, carries recognized complications including bleeding, pneumomediastinum, and mediastinal infection. In a patient whose trachea was already markedly narrowed by extrinsic compression, even modest bleeding into the airway could have precipitated life-threatening obstruction. The authors note that the small 1.1-millimeter cryoprobe requires only a tiny puncture tract, which may theoretically reduce procedural risks compared with larger devices such as forceps or electrocautery instruments. The successful completion of the procedure, with discharge the following day and no airway compromise, suggests that in carefully selected patients, substantial airway compression need not disqualify a patient from this minimally invasive route to diagnosis.

The broader lesson of this case report, published in Respirology Case Reports, is that sampling technique can be the deciding variable in cancer diagnosis. EBUS-TBNA remains an outstanding tool for many mediastinal questions, particularly lung cancer staging, but when a suspected lymphoma demands assessment of tissue architecture and an extensive immunophenotypic workup, larger and better-preserved specimens can make the difference between an inconclusive result and an actionable answer. Cryobiopsy through the EBUS tract offers exactly that, using physical freezing rather than mechanical cutting to preserve the fragile cellular detail that immunohistochemistry depends upon. For patients with mediastinal masses, especially those compressing the airway, the prospect of a definitive diagnosis without open surgery, delivered through a probe thinner than a pencil lead and often within a single hospital day, represents a meaningful step forward in interventional pulmonology. As experience with EBUS-Cryo accumulates, this frozen needle may become a standard complement to conventional needle aspiration, ensuring that tumors like the one discovered on this young woman’s routine X-ray can be named, classified, and treated without delay.

Subject of Research: Diagnosis of primary mediastinal T-lymphoblastic lymphoma using endobronchial ultrasound-guided transbronchial mediastinal cryobiopsy

Article Title: Primary Mediastinal T‐Lymphoblastic Lymphoma With Airway Stenosis Diagnosed Using Endobronchial Ultrasound‐Guided Transbronchial Mediastinal Cryobiopsy: A Case Report

Article References: Nagamine, H., Bungo, M., Nagaki, Y., Todoriki, A., Niina, K., Enomoto, K., Kakuno, S., Nakai, T., Yamada, K., Watanabe, T., Asai, K., Mukai, D., Nagasaki, J., Nakamae, H., & Kawaguchi, T. (2026). Primary Mediastinal T‐Lymphoblastic Lymphoma With Airway Stenosis Diagnosed Using Endobronchial Ultrasound‐Guided Transbronchial Mediastinal Cryobiopsy: A Case Report. Respirology Case Reports, 14(9), Article e70756. https://doi.org/10.1002/rcr2.70756

Image Credits: AI Generated

DOI: 10.1002/rcr2.70756

Keywords: T-lymphoblastic lymphoma, EBUS-Cryo, cryobiopsy, mediastinal mass, airway stenosis, EBUS-TBNA, interventional pulmonology, immunohistochemistry, bronchoscopy, lymphoma diagnosis, case report, Respirology Case Reports

Thymomas are tumors arising from the epithelial cells of the thymus, the organ behind the breastbone where immune cells called T lymphocytes mature. In goats, the thymus has paired cranial and cervical lobes plus a single thoracic lobe, and tumors can develop in the cranial mediastinum, the space between the lungs, or in the ventral neck region. Post-mortem surveys suggest thymomas make up roughly ten percent of all tumors in goats, and dairy breeds such as Nigerian Dwarf and Saanen may carry an even higher prevalence, with one classic study reporting rates as high as twenty-five percent. Despite how common they appear to be at necropsy, almost nothing has been published about actually treating them.

The goat arrived at the University of Florida Large Animal Hospital after several days of lethargy, fever, and reduced appetite. On examination she was febrile at 106.2 degrees Fahrenheit, with rapid heart and respiratory rates, hyperemic mucous membranes, poor rumen contractions, and a heart murmur. Bloodwork revealed elevated fibrinogen and creatine kinase, low protein and calcium, and abnormalities on venous blood gas. A point-of-care thoracic ultrasound uncovered the likely culprit: a mass in the cranial mediastinum, alongside B-line artifacts and small areas of consolidation in the front of the chest that pointed to pneumonia.

A computed tomography scan performed under general anesthesia characterized the mass in detail. It measured 8.6 by 6.5 by 6 centimeters, appeared heterogeneous in soft tissue and fluid attenuation, and enhanced strongly with contrast. The tumor was displacing the cranial vena cava caudodorsally, pushing the heart backward, and compressing the cranial lung lobes, but there was no vascular invasion. Ultrasound-guided fine-needle aspiration yielded lymphoid tissue with poorly preserved epithelial cell aggregates and occasional mast cells, findings most consistent with a neoplasm of thymic origin, suspected to be a thymoma. The team also identified patterns consistent with aspiration or chronic bronchopneumonia and treated the goat empirically with florfenicol.

Treatment options were weighed carefully with the owner. Surgical excision was declined because of the substantial risk of intraoperative hemorrhage, a complication that has proven fatal in the only two goats previously reported to undergo thoracic surgery for mediastinal thymoma. Radiation therapy was offered instead, with candid discussion of acute risks including pneumonitis, esophagitis, tracheitis, and myocarditis, and late risks such as cardiomyopathy, arrhythmia, and lung fibrosis. The owner elected a palliative-intent protocol of four weekly fractions of 8 Gy, totaling 32 Gy, a schedule chosen to reduce costs and minimize the number of hospital visits and anesthetic episodes.

The technical execution of the plan illustrates how far veterinary radiation oncology has come. The goat was positioned in sternal recumbency in a vacuum-sealed cushion for a planning CT scan. The contrast-enhancing mass was contoured as the gross tumor volume, expanded uniformly by 2 millimeters to create the planning target volume. Because thymomas typically move little with respiration, no internal target volume was used, and the small margin prioritized sparing nearby organs at risk: the lungs, heart, esophagus, trachea, and spinal cord. An inverse-planned intensity-modulated plan with eight coplanar isocentric beams was generated on the Eclipse planning system, normalized so that 95 percent of the target received the full prescription dose, with only 5.6 percent of lung volume receiving 20 Gy or more.

Quality assurance was rigorous. The plan was verified with a two-dimensional diode array, requiring at least 95 percent of measured points to agree with the calculated fluence at a 3 percent and 3 millimeter criterion. Treatment was delivered with 6 MV photons from a Varian Edge linear accelerator equipped with a 120-leaf multileaf collimator, and cone-beam CT scans taken before each session confirmed accurate positioning. Each fraction required general anesthesia, induced with propofol after butorphanol and midazolam premedication and maintained on isoflurane, with no complications. By the fourth fraction, the cone-beam CT already showed the tumor shrinking by roughly 5 millimeters in every dimension, and the goat’s appetite had returned to normal while her heart murmur had quieted.

The response endured. A recheck CT scan four months after treatment, performed during an unrelated emergency visit for fever and lethargy, showed the mass had shrunk to 6 by 4.6 by 5.2 centimeters, a 30 percent reduction that meets the formal definition of a partial response under Veterinary Cooperative Oncology Group RECIST criteria. The pulmonary changes seen before treatment had nearly resolved. A scan at ten months confirmed a persistent partial response, though it also revealed mild progression of lower airway inflammation and bronchopneumonia that the authors could not rule out as a low-grade late radiation effect or unrelated chronic bronchitis. Twenty months out, the owner reported only occasional mild coughing, and the goat was still alive at the time of manuscript submission, roughly 1,230 days after treatment began.

The result carries weight because the comparative literature is so thin. Only one previous goat with a cranial mediastinal thymoma had been treated with radiation, receiving 32 Gy in 4 Gy fractions every other day, with tumor regression noted by the sixth fraction and survival of at least 1.5 years. In dogs and cats, surgery remains the treatment of choice for thymoma, though perioperative mortality approaches 20 percent, and radiation produces overall response rates of 33 to 75 percent with median survival times of 5 to 8 months in dogs and 24 months in cats. Because metastasis is rarely seen in caprine thymoma, local control is the central therapeutic goal in goats as well, making radiation an attractive alternative when thoracic surgery is too risky or unavailable.

The authors acknowledge limitations, most notably that the diagnosis rested on cytology rather than the histopathology required for definitive confirmation of thymoma. They also note that the link between the goat’s pneumonia and the tumor is uncertain; in dogs, thymoma-associated megaesophagus drives aspiration pneumonia, but myasthenia gravis appears far less common in goats, and no megaesophagus was seen on CT. Still, the message is clear. As goats increasingly live as companion animals rather than production livestock, cancer care becomes a relevant expectation for their owners, and this case demonstrates that modern, image-guided, hypofractionated radiation therapy is technically feasible in goats, was well tolerated, and can produce objective, durable tumor shrinkage. Larger cohorts will be needed before firm recommendations can be made, but for pet goats facing inoperable mediastinal thymoma, radiation therapy now stands as a legitimate option to discuss.

Subject of Research: Palliative hypofractionated image-guided intensity-modulated radiation therapy for a cranial mediastinal thymoma in a Nigerian Dwarf goat

Article Title: Image-guided intensity-modulated radiation therapy for a mediastinal thymoma in a Nigerian Dwarf goat: a case report

Article References: Argenti, T., Jodzio, D., Hancock, K., Darby, S., Luethy, D., Gilor, S., Gutti, J., & Takada, M. (2026). Image-guided intensity-modulated radiation therapy for a mediastinal thymoma in a Nigerian Dwarf goat: a case report. Veterinary Oncology, 3(1), Article 4. https://doi.org/10.1186/s44356-026-00055-6

Image Credits: AI Generated

DOI: 10.1186/s44356-026-00055-6

Keywords: thymoma, goat, radiation therapy, IMRT, veterinary oncology, Nigerian Dwarf goat, mediastinal mass, hypofractionated radiation, computed tomography, palliative care, caprine neoplasia, partial response