Fine needle aspiration cytology of glycogen-rich clear cell carcinoma of the breast: review of 37 cases with histologic correlation.

OBJECTIVE: To analyze fine-needle aspiration cytology (FNAC) material from 37 cases of breast glycogen-rich clear cell cancer (GRCC) and correlate cytomorphologic features with histologic appearance to determine characteristics of GRCC on FNAC.

STUDY DESIGN: We reviewed cytologic features of 37 cases of breast GRCC from the archives of Ege University Hospital diagnosed between 1994 and 2006.

RESULTS: Thirty-seven patients with available aspirate and confirmed GRCC were identified. The female patients ranged from 32 to 81 years (mean 52 years). The initial cytologic diagnoses were adenocarcinoma for 27 and atypical or suspicious for cancer for 10. The cytologic picture was characterized by hypercellular tumor cells in loosely cohesive syncytial groups and some single cells. Most tumor cells had abundant, finely granular eosinophilic cytoplasm or foamy to clear cytoplasm with well-defined cytoplasmic membranes and moderate to marked nuclear pleomorphism with prominent nucleoli. Histologic examination confirmed all cases to be pure GRCC.

CONCLUSION: Breast GRCC is a rare, distinct category with cytologic features that overlap considerably with those of other carcinomas. Awareness of variability in cytomorphologic appearance of GRCC and routine assessment for glycogen facilitate accurate diagnosis of these lesions by FNAC and enable prompt treatment of these poor-prognosis breast cancers.