Glycogen-rich clear cell carcinoma of the breast : a case report and review of the literature

A case of glycogen-rich clear cell carcinoma (GRCCC) arising in the left breast of a 46-year-old Japanese woman is herein described. Fine-needle aspiration cytology of the breast mass revealed the presence of malignant cells and the patient underwent modified radical mastectomy. Pathologically, the tumor revealed proliferation of cancer cells with markedly vacuolated cytoplasm. The presence of a large amount of glycogen in the cytoplasm was proven by periodic acid-Schiff (PAS) stain after diastase digestion and electron microscopy. The tumor was thus diagnosed to be a solid variant of GRCCC. The resected tumor was negative for estrogen and progesterone receptors. Neither any axillary nodal involvement or distant metastasis was observed. Based on a review of22 such cases in the literature, including the case reported herein, this type of breast carcinoma is considered to reveal a frequent nodal involvement and more aggressive clinical course than the usual types of breast cancer.