Rare breast tumors

During a consultation an oncologist occasionally comes across cases of rare malignant breast tumors that require separate approaches both to diagnostics and treatment. Cytological diagnostics by itself, unfortunately, does not allow to correctly identify the type of a tumor and assess a chemotherapy protocol as well as the need for neoadjuvant (preoperative) treatment. 

Only histological and immunohistochemical examinations allow to establish the correct diagnosis. For this purpose, trephine biopsy is performed. Many rare carcinomas are ‘triple negative’, particularly medullar, metaplastic, squamous, adenocystic, and mucoepidermoid carcinomas. Neuroendocrine carcinomas, on the contrary, may have estrogen and progesterone receptors. 

Breast sarcomas are also a very uncommon pathology. They usually manifest as a large breast tumor without axillary lymph node involvement. 

Metastases of other tumors (melanoma, tumors of the gastrointestinal tract, lungs, gynecological and urological tumors, head and neck tumors, sarcomas, lymphomas, etc.) in the breast may imitate the primary tumor. A thorough immunohistochemical study and complete patient examination are critical in diagnostics. 

Implant-associated lymphomas should be mentioned separately. They are characterized by accumulation of fluid around the implant which contains CD30+ lymphocytes that are the substrate of the tumor. The same cells can be found in the tissues surrounding the implant’s capsule. 

Rare tumors are different from the ‘classic’ types of cancer in their sensitivity to anti-tumor treatment and prognosis. For many kinds of rare tumors there are no standards of treatment. This applies to both chemotherapy and radiotherapy as well as the need to remove axillary lymph nodes (sarcomas, adenocystic carcinoma etc.).