A Diagnostic Dilemma in Fine-Needle Aspiration Cytology: Spindle Cell/Pleomorphic Lipoma.

Pleomorphic lipoma is an uncommon, pseudosarcomatous lesion. It is characterized by the pleomorphic appearance on cytology and histology, follows a benign course, with a low rate of recurrence after complete excision, and has no risk of metastasis. Here, we describe a case of pleomorphic lipoma/spindle cell lipoma in a 41-year-old man who presented with a slow-growing mass on the inner aspect of the left thigh. On fine-needle aspiration cytology, it was reported as a cellular nerve sheath tumour followed by a wide excision sample sent for histopathological examination, which revealed spindle cells exhibiting pleomorphism with mature adipocytic cells and multinucleated floret cells in a myxoid background. It was reported as pleomorphic lipoma on histological examination.