Sclerosing Perivascular Epithelioid Cell Tumor of the Lung: A Case Report with Cytologic Findings.

Benign perivascular epithelioid cell tumor (PEComa) of the lung is a rare benign neoplasm, a sclerosing variant of which is even rarer. We present a case of 51-year-old man who was diagnosed with benign sclerosing PEComa by percutaneous fine needle aspiration cytology and biopsy. The aspirate revealed a few cell clusters composed of bland-looking polygonal or spindle cells with fine granular or clear cytoplasm. Occasional fine vessel-like structures with surrounding hyalinized materials were seen. The patient later underwent wedge resection of the lung. The histopathological study of the resected specimen revealed sheets of polygonal cells with clear vacuolated cytoplasm, variably sized thin blood vessels, and densely hyalinized stroma. In immunohistochemical studies, reactivity of tumor cells for human melanoma black 45 and Melan-A further supported the diagnosis of benign sclerosing PEComa. To the best of our knowledge, this is the first case of benign sclerosing PEComa described in lung.