Myopericytomatosis: Clinicopathologic Analysis of 11 Cases With Molecular Identification of Recurrent PDGFRB Alterations in Myopericytomatosis and Myopericytoma.

摘要: Myopericytoma is a benign tumor of concentrically distributed perivascular myoid cells. Its molecular basis and relationship with myofibroma/myofibromatosis other pericytic tumors are not fully understood. In our consultation/surgical files over 1000 myopericytic lesions, we identified 11 cases diffuse dermal/subcutaneous involvement by microscopic myopericytomatous nodules, phenomenon have termed myopericytomatosis. Myopericytomatosis affected mostly adults (female:male=8:3; median age, 37 y; range, 9 to 63 y) in the lower extremities (foot/ankle, 5; calf, 3; knee, 1; thigh, neck, 1) months 25 years, ranging from 1.5 11.0 (median, 6.0) cm size. Histologically, myopericytomatosis displayed infiltration innumerable discrete myopericytoma/myofibroma-like nodules bland spindled-to-ovoid cells (smooth muscle actin positive), mainly distribution. No mitoses, atypia, or necrosis was noted. All patients were treated surgical excision (1 patient also received adjuvant radiation), margins focally positive 5 6 known cases. Of follow-up 0.2 13.7 3.4) 1 recurred locally twice, while showed no recurrence. Targeted next-generation DNA sequencing PDGFRB alterations all conventional myopericytoma tested (5 each), including mutations 4 (N666K Y562-R565 deletion case) 3 myopericytomas (Y562C, K653E, splice acceptor case as well low-level amplification 2 myopericytomas. BRAF, NOTCH, GLI1 detected. summary, rare, strikingly diffuse, but apparently variant that typically involves superficial soft tissue nodules. The strongly activating mutation N666K noted myopericytomatosis, myopericytoma, suggesting status may account for their pathogenetic differences. As present myopericytoma/myopericytomatosis infantile myofibromatosis/myofibroma, these entities indeed lie within histogenetic continuum. Identification suggests tyrosine kinase inhibition potential therapeutic strategy neoplasms if needed.