ANSWERMyopericytomatosis.
DISCUSSIONMyopericytoma (MPC) is a mesenchymal neoplasm of perivascular myoid cells, usually found in the subcutaneous tissue of the distal extremities, and most often presenting as a slow-growing nodule in men more than women. 1 These typically painless nodules generally develop during adulthood. 2 Although considered benign, MPC has been reported to recur after trauma. 3 These vascular proliferations contain ovoid spindle-shaped myopericytes that are only found in the dermis. 3 Myopericytomas are considered to represent a transition between pericytes and smooth muscle cells 3,4 that are able to differentiate into modified smooth muscle cells normally found in capillaries. 5 Myopericytomas are typically slowgrowing neoplasms and are usually less than 2 cm in greatest dimension 6 and present as a painless discrete nodule with a gray-white colored appearance on physical examination. 7,8 These nodules can be found in a variety of areas within the body, including the neck, 9 trunk, 9 and nervous system. 10 Biopsy from the opposite thigh in our patient showed similar features, and multicentric cases have been reported.Excision biopsy is optimal for histopathological examination and immunophenotypic evaluation, 11 which shows nodular proliferation of concentric round or ovoid eosinophilic spindle cells with an onion skin pattern. 5,6 Cases may have close resemblance to glomangioma or focal areas of glomangioma-like cytology. 1 Immunohistological staining is positive for SMA and h-caldesmon. 5 These cells composing the thick vessel walls are generally negative for desmin and CD34, 7 as in our case.The prognosis of MPC is generally favorable because it is usually benign. 8 However, some cases of malignant MPC have been reported. 6 Such lesions exhibit mitoses, necrosis, and nuclear atypia. 5 Symptomatic MPCs may be managed by excision. 5 The reported recurrence rate is 10%-20%. 5 Postoperative management includes surveillance in case of recurrence. 11