Key result
Endovascular biopsy identifies primary leiomyosarcoma after deep vein thrombosis refractory to apixaban.
Why the study?
Primary venous leiomyosarcoma is a rare malignant smooth-muscle tumour that may mimic DVT and potentially delay diagnosis.
Case Report (n=1)
No
Progression of an apparent deep-vein thrombosis despite adherent anticoagulation and unexpected mechanical resistance during endovascular thrombectomy should prompt histological biopsy and MRI to evaluate for primary venous malignancy such as leiomyosarcoma.
Answers are grounded in this paper and cite their sources.
Consider venous leiomyosarcoma in anticoagulation-refractory DVT; single case leaves open need for prospective diagnostic validation.
Background: Primary venous leiomyosarcoma is a rare malignant smooth-muscle tumour that may mimic deep-vein thrombosis (DVT), potentially delaying diagnosis. Case presentation: A 77-year-old man presented with spontaneous right-leg pain, swelling and pitting oedema. Ultrasonography demonstrated incomplete compressibility and intraluminal material within the right common femoral vein and great saphenous-femoral junction. The femoral, popliteal and iliac veins were patent. Apixaban was commenced using the recommended loading regimen, followed by 5 mg orally twice daily and this was adhered to. Despite approximately 11 weeks of anticoagulation, his symptoms persisted and repeat ultrasonography demonstrated apparent proximal extension into the distal right external iliac vein. CT pulmonary angiography identified a small right subsegmental pulmonary embolus. CT venography demonstrated right external iliac venous thrombosis and focal iliac venous narrowing.Endovascular thrombectomy was attempted, but the intravascular material was exceptionally firm and resistant to mechanical extraction, cutting techniques and balloon angioplasty. As a result a biopsy was taken using a myocardial biopsy forceps..Histological examination of same demonstrated a high-grade spindle-cell malignancy expressing actin, desmin and h-caldesmon. The Ki-67 proliferation index ranged from 20% to 70%, establishing a diagnosis of a high-grade leiomyosarcoma with associated vascular thrombosis. Subsequent contrast-enhanced MRI demonstrated a 7 cm enhancing intravascular mass centred in the right common femoral vein, extending into the proximal femoral vein, great saphenous vein and a short segment of a profunda femoris venous branch. There was no convincing extravascular extension or distant disease on imaging. Conclusion: Progression of an apparent DVT despite appropriately administered anticoagulation should prompt consideration of an alternative diagnosis. “Thrombus” which does not respond to thrombectomy mandates histological examination.
No takes yet. Share an insight, caveat, or question.
Hoef et al. (2026) conducted a case report in Primary high-grade leiomyosarcoma of the common femoral vein masquerading as deep-vein thrombosis (n=1). Apixaban followed by endovascular thrombectomy and intravascular biopsy was evaluated on Histological and radiological diagnosis of anticoagulation-resistant intravascular mass. Endovascular biopsy and MRI identified a 7 cm primary high-grade leiomyosarcoma (Ki-67 20%-70%) in the right common femoral vein after DVT progressed despite 11 weeks of apixaban.
Synapse has enriched 10 related papers. Consider them for comparative context: