Fine-needle aspiration of pigmented villonodular synovitis of the temporomandibular joint masquerading as a primary parotid gland lesion.

The fine-needle aspiration findings in a case of pigmented villonodular synovitis of the temporomandibular joint are presented. The characteristic cytomorphologic and clinical features of this uncommon, benign fibrohistiocytic lesion are discussed. In addition, due to the initial clinical impression of a primary parotid gland lesion, the differential diagnosis for the cytomorphologic features observed (histiocytoid cells admixed with osteoclast-like giant cells) are discussed within the context of a primary salivary gland mass.