ABSTRACT
Background: Cystic Hypersecretory Carcinoma (CHC) is a rare subset of breast carcinoma. It is part of a spectrum of cystic hypersecretory lesions which includes cystic hypersecretory hyperplasia (CHH), CHH with atypia, CHC in situ and CHC with invasion. Approximately 65 cases of cystic hypersecretory lesions have been reported; most of them were CHC in situ and only 19 cases of CHC with invasion have been reported so far. Case Presentation: We are reporting 2 cases of 47 and 62 year old women with a palpable breast mass for 6 and 1 month duration respectively. Trucut biopsy was carried out for both which showed high grade ductal carcinoma in situ with microinvasion in the first patient and the latter showed a tiny focus of invasive carcinoma. Simple mastectomy and modified radical mastectomy (MRM) were done for the respective cases; both showed dilated cystic spaces filled with eosinophilic secretions (thyroid colloid-like), lining neoplastic cells that showed variable degrees of proliferation, atypia and in situ carcinoma. There were foci of invasion in both cases and hence a morphological diagnosis of CHC with invasion was made. Conclusion: Owing to a smaller number of reported cases, little is known about the biological behavior, prognosis and molecular profile of cystic hypersecretory carcinoma.