G M Tse1, E W To, E H Yuen, M Chen. 1. Department of Anatomical and Cellular Pathology, Prince of Wales Hospital, Chinese University of Hong Kong, Shatin, NT. garytse@cuhk.edu.hk
Abstract
BACKGROUND: Basal cell adenocarcinoma of the parotid is rare and prone to recur. CASE: A 54-year-old woman had a history of afacial mass 12 years earlier that had been excised and was diagnosed as low grade adenocarcinoma of the parotid. Over the years, the patient had multiple local and lymph node recurrences. Histology of the excised local recurrent tumor showed basal cell adenocarcinoma, and FNAC of a separate recurrent nodule was performed. The aspirate showed moderate cellularity of basaloid cells with mildly pleomorphic nuclei, small nucleoli and occasional mitotic figures. The cells were mostly single, but some formed clusters with a rosettelike pattern of tumor cells surrounding central eosinophilic globules. A second, less prominent population of smaller cells with dark-staining nuclei was also noted. The differential diagnosis included adenoid cystic carcinoma, polymorphous low grade adenocarcinoma, and basal cell and pleomorphic adenoma. CONCLUSION: The cytologic features of basal cell adenocarcinoma are not distinctive, but the presence of two cell populations with moderate pleomorphism and a rosettelike pattern with central, eosinophilic globules may assist with its differentiation from other salivary gland neoplasms.
BACKGROUND: Basal cell adenocarcinoma of the parotid is rare and prone to recur. CASE: A 54-year-old woman had a history of afacial mass 12 years earlier that had been excised and was diagnosed as low grade adenocarcinoma of the parotid. Over the years, the patient had multiple local and lymph node recurrences. Histology of the excised local recurrent tumor showed basal cell adenocarcinoma, and FNAC of a separate recurrent nodule was performed. The aspirate showed moderate cellularity of basaloid cells with mildly pleomorphic nuclei, small nucleoli and occasional mitotic figures. The cells were mostly single, but some formed clusters with a rosettelike pattern of tumor cells surrounding central eosinophilic globules. A second, less prominent population of smaller cells with dark-staining nuclei was also noted. The differential diagnosis included adenoid cystic carcinoma, polymorphous low grade adenocarcinoma, and basal cell and pleomorphic adenoma. CONCLUSION: The cytologic features of basal cell adenocarcinoma are not distinctive, but the presence of two cell populations with moderate pleomorphism and a rosettelike pattern with central, eosinophilic globules may assist with its differentiation from other salivary gland neoplasms.