engleski

Pediatric malignant perivascular epiteloid cell tumor with unusual immunophenotype

Objective: Perivascular epitheloid cell tumor (PEComa) represents a rare group of mesenchymal neoplasms characterized by the presence of epitheloid cells of mixed myo-melanocytic differentiation with unpredictable malignant potential expressing myogenic and melanocytic markers. We present a case of malignant PEComa of soft tissue in a 10-year old girl with peculiar melanocytic tumor cells “immunophenotype” negative for HMB-45 and Melan, but positive for MITF. Methods and Results: A 10-year-old girl presented with a 3-week history of slowly progressive painless, well circumscribed swelling, measuring 3 cm in diameter, under her left clavicle. The ultrasound showed well defined, echogenic heterogeneous soft tissue mass with discrete vascularization. Fine needle aspiration was suspicious for malignant mesenchymal tumor therefore complete resection was done. Macroscopically, the mass was whitish and lobular while microscopic findings confirmed diagnosis of PEComa. Two weeks after the surgery, at the site of the primary tumor, the painless nodules were palpable, measuring 5 and 10 mm in diameter respectively. Re-excision was performed, showing a tumor with the same morphology as earlier lesion. Conclusion: Tumors of this type are often associated with an aggressive clinical course although the majority of PEComas exhibit benign or indolent behavior. To the best of our knowledge, this is the first reported case of malignant PEComa in such young patient.

PEComa

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