Pathology of Piloleiomyoma

Dr Sampurna Roy MD                       2022

Piloleiomyomas are benign smooth muscle tumors arising from the arrectores pilorum muscles in the skin.

The tumour usually presents as multiple reddish brown nodule.

These are usually painful or sensitive to touch and cold.

Solitary lesions are rare and are usually larger than the multiple form (upto 2cm or more in diameter).

These are usually noted in the second and third decade of life.

Common sites include face, back, and the extremities.

 

Microscopic features:  

These are circumscribed non encapsulated tumours characterized by  bundles and and fascicles of smooth muscle cells.

Tumour cells are characterized by eosinophilic cytoplasm with vesicular nuclei. 

Rarely, occasional mitotic figures may be present.

Immunohistochemistry reveals that the tumour cells are positive for actin and desmin.    

Genital Leiomyoma ;   Angioleiomyoma ; Lipoleiomyoma

Piloleiomyoma mistaken for postacne scarring.

Bilateral multiple piloleiomyomas on the breast. 

Piloleiomyoma--a report of five cases.

An atypical piloleiomyoma presenting as a nonhealing ulcerated nodule.

Piloleiomyoma arising in an organoid nevus: a case report and review of the literature.

A case of multiple piloleiomyoma associated with submucosal tumor of the stomach.

Arrector pili nevus--histological comparison to piloleiomyoma and study of reported cases in Japan