Pericytic Lesions: A Paradigm of Overlapping Features

Although myopericytoma and glomangiopericytoma are considered the subtypes of the group myopericytomas (MPC), they differ morphologically. Both of the tumors arise from pericytic cells. Scalp MPC are infrequent, but extranasal glomangiopericytomas are extremely rare. Herein, we report a case of a 36-year-old female presenting with slowly growing scalp swelling. Histopathology showed a dermal tumor with features of myopericytoma as well as glomangiopericytoma within the same lesion. Immunohistochemistry and reticulin staining confirmed pericytic origin but could not differentiate between the two tumors. This case report adds to the rarity and morphologic heterogeneity of the group MPC.