Glycogen-rich clear cell carcinomas of the breast. A clinicopathologic and ultrastructural study.

Ten cases of glycogen-rich clear cell carcinoma of the breast are described. Only two previous case reports have been published. These neoplasms are composed of clear cells with abundant glycogen. Ultrastructurally, two cases showed large quantities of non-membrane-bound glycogen and numerous empty glycogen lakes. neoplastic cells formed tight junctions, immature desmosomes, and occasionally had short microvilli. In nine cases the glycogen-rich carcinoma grew in a solid pattern only, while one case had both solid and papillary patterns. One case was associated with a signet-ring cell carcinoma. Seven of nine patients who underwent axillary dissections had nodal metastases. Five patients died with residual disease, and one is currently alive with local skin recurrence. These data suggest that glycogen-rich clear cell carcinoma is associated with frequent lymph node metastases and mortality.