February 2018
- 28 year old male presented with a subcutaneous mass on his forehead.
- Cyst
- Lipoma
- Spiradenoma
Sections show a nodular subcutaneous mass composed of spindled and epithelioid cells associated with blood vessels and a myxoid stroma.
Immunohistochemical stain for smooth muscle actin (SMA) is positive within the spindle cells.
Adult myofibroma
- Adult myofibroma is a solitary, benign mesenchymal neoplasm that commonly presents on the head/neck region within the dermis or subcutaneous tissue.
- Histopathology reveals a nodular, biphasic mesenchymal neoplasm composed of myofibroblasts in fascicles or whorls and collections of small, primitive cells associated with hemangiopericytoma-like blood vessels. An accompanying myxoid or chondroid stroma is also present.
- The spindle cells express smooth muscle actin by immunohistochemistry. They are negative of desmin, EMA and S-100.
- A related entity is infantile or multicentric myofibromatosis, which is characterized by multifocal myofibromas typically presenting during the first decade of life. Visceral involvement and spontaneous regression can be seen.
- An autosomal dominant inheritance pattern is seen in some cases
- Adult myofibroma, glomangiopericytoma and myopericytoma likely represent a histopathological continuum of tumors
- Adult myofibromas are benign and excision is curative. Some lesions of adult myofibromas may spontaneously regress.
- Adult myofibroma is a solitary, benign mesenchymal neoplasm that commonly presents on the head/neck region within the dermis or subcutaneous tissue
- Histopathology reveals a nodular, biphasic mesenchymal neoplasm composed of myofibroblasts in fascicles or whorls and collections of small, primitive cells associated with hemangiopericytoma-like blood vessels. An accompanying myxoid or chondroid stroma is also present.
- The spindle cells express smooth muscle actin by immunohistochemistry. They are negative of desmin and S-100.
- Adult myofibromas are benign and excision is curative