Sclerosing polycystic adenosis of the left parotid gland: report of a case with fine needle aspiration cytology.

BACKGROUND: Sclerosing polycystic adenosis (SPCA) of major salivary glands is a rare recently described entity. We report a case of SPCA of the left parotid gland, including the cytologic and histopathologic findings.

CASE: A 20-year-old man presented with a left parotid mass that had been growing slowly for 3 years. Fine needle aspiration cytology showed many syncytial cell clusters of variable size and some ductal structures with an inflammatory background. The cells forming syncytial clusters were large and polygonal, with abundant, eosinophilic, granular or lacelike cytoplasm. Apocrine differentiation with decapitation secretion was commonly seen. The ductal cells had a relatively high nuclear/cytoplasmic ratio, with granular cytoplasm. Grossly, the 5-cm lesion was a discrete, pale, cystic nodule embedded within the parotid gland parenchyma. Microscopically, the lesion was a nonencapsulated, circumscribed mass of sclerotic and hyalinized, collagenous tissue with lymphoplasmacytic infiltration. Sclerosing adenosis and cystic ducts with frequent apocrinelike cells were commonly seen. Some acinar cells contained eosinophilic, intracytoplasmic granules of various sizes.

CONCLUSION: The presence of syncytial clusters with apocrine metaplasia and ductal structures in a lymphoplasmacytic background should suggest a diagnosis of SPCA of a major salivary gland.