目的探讨乳腺颗粒细胞瘤(GCT)临床病理特征及诊断和鉴别诊断。方法复习1例乳腺颗粒细胞瘤的临床病理资料进行病理形态和免疫组化观察。结果 1例GCT无特殊临床症状及体征,细胞境界清楚,胞体宽大,胞浆丰富,充满大的嗜酸性颗粒,浸润性生长,瘤细胞S-100(+),PAS(+),VIM(+),CEA(-)。结论乳腺颗粒细胞瘤少见,临床、细胞学及冰冻快速病理检查均易误诊为恶性肿瘤,应提高对此疾病的认识,减少不必要的扩大手术。 Objective To investigate the clinicopathological features and diagnosis and differential diagnosis of granulosa cell tumor of the breast (GCT). Methods The clinicopathological data of 1 case of granulosa cell tumor of breast were reviewed for histopathology and immunohistochemistry. Results One case of GCT had no obvious clinical symptoms and signs, clear cell boundary, wide cell body, rich cytoplasm, large eosinophilic granules, infiltrative growth, S-100 (+), PAS (+), VIM ), CEA (-). Conclusions Breast granulosa cell tumor is rare. Clinical, cytology and rapid frozen pathological examination are easily misdiagnosed as malignant tumors. Awareness of this disease should be raised and unnecessary expansion surgery should be reduced.