Vascular smooth muscle tumors: 13 cases and a review of the literature

Abstract

Vascular smooth muscle tumors, benign or malignant, are rare and encompass a variety of neoplastic lesions characterized histologically by their similarity to adult smooth muscle tissue. Leiomyomatosis, a benign neoplasm, primarily arising from within the uterine and extrauterine venous systems, and leiomyosarcoma, a malignant neoplasm arising predominantly in larger veins, while relatively rare, are nevertheless a cause of significant morbidity and mortality. We present a review of case of leiomyomatosis and leiomyosarcomas seen over a 35-month period, and an 18-year review of the literature. All tissues were fixed in 10% formalin, photographed, examined, and gross features described. Tissue samples were processed for light microscopy and stained with hematoxylin–eosin. The clinical records were reviewed. Eight cases of intravascular leiomyomatoses and five cases of leiomyosarcomas are presented in this series. Gross findings of resected intravascular leiomyomatosis were remarkably similar, although tumor size varied greatly between patients. Histologically, the tumor masses were similar. Gross and histological analysis of leiomyosarcoma masses revealed tumors of varying grades of malignancy. Vascular smooth muscle tumors that extend through or directly involve the vasculature are rare and difficult to diagnose and manage. Surgical resection remains the most effective treatment, although chemotherapy in isolated cases has been shown to have a positive effect. Appropriate interpretation and diagnosis are crucial for effective management.