Malignant Perivascular Epitheloid Cell Tumor with an Unusual Immunophenotype in a Ten-Year-Old Child.

Perivascular epitheloid cell tumors (PEComa) represent a group of usually benign mesenchymal neoplasms. Malignant variants are usually found only in adults. We present a 10-year-old girl with infraclavicular malignant PEComa, negative for HMB-45 and Melan A but focally positive for MITF. To the best of our knowledge, no malignant variant of PEComa has been described in soft tissue in a child. Generally, PEComas are immunoreactive for HMB-45 and/or Melan A while our case was negative for both. Further studies are necessary to elucidate the significance of this immunohistochemical finding.