A benign, multifocal, nodular and well-circumscribed neoplasm usually seen as a congenital neoplasm or in the first year of life. It is characterized by a biphasic growth pattern and is composed of small, undifferentiated mesenchymal cells associated with branching thin-walled vessels and more mature neoplastic spindle cells with abundant eosinophilic cytoplasm in a collagenous stroma.

A condition characterized by multiple formations of myofibromas (LEIOMYOMA).

A mesenchymal neoplasm characterized by solitary or multiple nodules involving the skin, striated muscles, bones and, sometimes, viscera. It usually appears as a subcutaneous nodule, but can also appear as an ulcer, pedunculated lesion, or similar to a hemangioma. Histology shows well-circumscribed tapered cell lobes, resembling smooth muscle cells. At its center, perivascular round cells (hemangiopericitoides) are usually observed, giving a biphasic appearance.