Diagnosis and treatment of intracystic breast carcinomas.

Cystic breast masses are very common in female patients attending breast clinics. Most of them are benign and managed by simple aspiration. We reviewed histology records for the last 12 years to find patients with cystic breast carcinomas and to evaluate special clinical signs that may help to identify patients with this rare entity. Eighteen patients with cystic breast carcinomas were found among 1510 new breast cancer patients (1.19%) who were seen at our Breast Unit during this period. Ten had intracystic papillary carcinoma (0.66% of all breast cancers), seven had cystic degeneration of ductal carcinoma, and one had a mucinous carcinoma. The diagnosis of intracystic papillary carcinoma was based on cyst fluid cytology and breast imaging in most patients and on open breast biopsy in two cases only. The prognosis of our cystic breast carcinoma patients was excellent regardless of the specific histologic type of the tumor. We conclude that cysts in postmenopausal women should be viewed with suspicion. Bloodstained aspirated cyst fluid should be sent for cytology and breast imaging should be carried out in all these cases. Residual mass after cyst aspiration is also an indication for open biopsy.