Abstract
A 41-year-old woman visited our hospital complaining of a palpable left breast mass. An approximately 2.5 cm tumor was palpated and breast cancer was suspected by ultrasound examination. Core needle biopsy indicated glycogen-rich clear cell carcinoma (GRCCC) based on histopathological findings. The patient underwent partial mastectomy with axillary lymph node dissection. The tumor was stage IIA(T0, N0, M0). The pathological diagnosis was ER(+), PR(+), HER2(-) and S-100 protein(+). The residual breast was irradiated with 50Gy followed by hormone therapy, LH-RH agonist and tamoxifen citrate. GRCCC is a rare subtype of breast carcinoma, with a calculated incidence of 0.9-3.0%. It is composed almost entirely of polygonal cells with clear cytoplasm, containing large amounts of partly water-soluble glycogen. Recently, more than 50 cases have been reported in Japan, all women. It is necessary to follow-up these cases carefully because the biological characteristics of GRCCC are unclear.
