A cytomorphological study of the breast cancer with cyst formation

Abstract

We studied 6 cases of breast cancer with cyst formation cytomorphologically. During the last 6 years, our hospital treated 162 breast cancer cases and 6 (3.7%) of whom had cysts larger than 1 cm in diameter. Out of these 6 cases, three exhibited elevated cancerous lesions intracystically, termed intracystic carcinoma, all of which were diagnosed as papillotubular carcinoma. The other two cases had no elevated cancerous lesions in the cysts and the histopathological diagnoses were solid-tubular carcinoma and noninvasive ductal carcinoma. Cytological examination of the aspirated cystic fluid was performed in these 5 cases, and four were found to be malignant and one borderline. The last case had skin invasion and cyst formation due to intratumorous necrosis, and the histopathology was squamous cell carcinoma. Malignant cells were also detected by scratch cytology of the skin ulcer. In all 6 cases, atypical cells were detected by preoperative cytology, and the cytological features reflected the histopathology accurately. Thus, cytological examination is valuable especially in cases without elevated lesions that have cancer in the cyst wall and often escape clinical diagnosis. These findings may be considered to be precursors of intracystic carcinoma of the breast.