Abstract
A case of glycogen-rich cell carcinoma in a 47-year-old woman is described with cytological features. Aspiration cytology showed sheet-like clusters of relatively uniform tumor cells with round or oval nuclei. Cytoplasm was pale to palely eosinophilic and contained diastase-sensitive periodic acid-Schiff-positive vacuoles. A differential diagnosis should include lipid-rich carcinoma, secretory carcinoma, and signet-ring cell carcinoma, and ancillary stains should be carefully applied. The cytologic features of glycogen-rich carcinoma should be also kept in mind to avoid misdiagnosis due to the relative uniformity of tumor cells.
