CYSTIC CARCINOMA OF THE BREAST - A TRAP FOR THE UNWARY

Cystic breast masses are a common presentation to breast clinics. Whil e the majority of cysts can be managed by simple aspiration, a small p roportion are malignant. Histology records for a 10-year period have b een examined to identify patients with cystic breast carcinomas. In al l, 31 patients were identified Of these, 18 had cystic degeneration of high-grade tumours, while 13 had intracystic papillary carcinoma. Bot h of these tumour types were diagnosed by a combination of cyst fluid cytology and breast imaging. The prognosis of high-grade tumours was p oor, while that of intracystic papillary carcinomas was excellent. Aft er cyst aspiration, bloodstained fluid should be sent for cytology and breast imaging arranged in all patients. Patients in whom a cyst refi lls within 2 weeks of aspiration require a careful re-evaluation. Cyst s in postmenopausal women should be viewed with suspicion. Excision sh ould be performed in patients with positive cytology or imaging.