2. Department of Pathology, Baheya Center For Early Detection and Treatment of Breast Cancer, Egypt.
3. Department of Pathology, Helwan Faculty of Medicine, Helwan University, Egypt.
Invasive cystic hypersecretory carcinoma (invasive CHC) of the breast is extremely rare and underdiagnosed type of breast cancer that is not included in the WHO classification of breast tumors. It has distinct gross and microscopic features. To the best of our knowledge, only 20 cases have been reported in the English literatures. So far, no data have been documented about its response to chemotherapy.
Herein we reported another new case, 65-year-old, of invasive CHC received neoadjuvant chemotherapy followed by mastectomy with poor therapy response. On microscopic examination, our case showed the Coexistences of the three forms of cystic hypersecretory lesions together [Cystic hypersecretory hyperplasia, CHC and invasive CHC]. Axillary lymph node metastasis is rarely reported and only five cases presented by axillary lymph node metastasis in the literatures. All were stage N1. Our case is also unique in that it was presented with stage N3 lymph node metastasis, that involved both axillary and infraclavicular lymph nodes. In conclusion, invasive CHC is a rare type of breast cancer and pathologist should be aware of it to help in the differential diagnosis, especially on examining a biopsy material.
Keywords: Cystic hypersecretory carcinoma, breast cancer, neoadjuvant therapy