Leiomyosarcoma of the deep femoral vein. A rare cause of venous obstruction in lower limbs and an alternative diagnosis to chronic venous thrombus.

Primary venous leiomyosarcoma of the extremities is an uncommon, but aggressive, tumoral entity with a high rate of local recurrence and early hematogenous metastasis. In the present article, we report a case of leiomyosarcoma of the vena profunda femoris. This pathology causes deep venous thrombosis-like symptoms. No improvement in lower limb status and a significant and progressive increase in the diameter of the vein as seen using ultrasonography could indicate tumor disease. Particular care must be taken to avoid biopsies due to the possible dissemination. We must complete the medical study with imaging techniques, and the tumor must be removed as soon as possible for histopathological diagnosis. After a follow-up of 12 months, there was no evidence of local or metastatic recurrence in our patient.