Fine needle aspiration cytology of a sebaceous lymphadenoma: a case report

BACKGROUND: Sebaceous lymphadenoma is a rare, benign neoplasm, histologically characterized by proliferating islands of epithelium with sebaceous glandular differentiation in a dense, lymphocytic background. The parotid gland is the most common site, and the patient usually presents with a well-circumscribed, enlarging and painless mass. Primary sebaceous lesions of the salivary glands are very rare entities and must be differentiated from more common, potentially malignant tumors. CASE: A 75-year-old male presented with a 6-month history of a mass in the tail of the parotid gland. The mass was not fixed or tender to palpation, was well delineated and measured 4 cm in greatest dimension. Fine needle aspiration (FNA) revealed a mixed population of large and small lymphocytes, including plasma cells and occasional tingible body macrophages. Scattered among the lymphocytes were 3-dimensional, cohesive aggregates of epithelial cells, many demonstrating the characteristic cytoplasmic vacuolization of sebocytes, surrounded by layers of basaloid cells. No mitoses or cellular pleomorphism was identified. These findings suggested a sebaceous lymphadenoma, confirmed on biopsy. CONCLUSION: Although sebaceous lymphadenoma is encountered infrequently, FNA findings can result in its accurate diagnosis.