Uterus, angioleiomyoma, caldesmon stain

Uterine angioleiomyoma is an extremely rare variant of leiomyoma, characterized by growth of smooth muscles surrounded by abundant arteriole-like vessels. In most cases, as in this case, atypia and significant mitotic activity are absent. Owing to its relative rarity, the diagnostic challenge is to rule out other more significant tumours. For example, tumours in the PEComa family may have prominent smooth muscle and vessels (in this case, HMB45 and MART1 were negative). The strong desmin and caldesmon staining in this case supports classification as a smooth muscle tumour. Because of its vascularity, it may predispose to clinical significant hemorrhage. Otherwise, there does not appear to be a clinical significance compared to benign leiomyoma.

This slide is caldesmon stain; see Related Content for H&E stain.

Reference: Garg G and Mohanty SK, Archiv Pathol Lab Med 2014;138:1115-8.