In this paper, we are presenting the two cases of very rare tumors: breast sebaceous carcinoma, which has been described for the first time in Croatian medical literature, and pure breast squamous carcinoma. First case, sebaceous carcinoma, is still quite unknown regarding its morphological characteristics and biological behavior. In the second case, squamous carcinoma, also very rare, was found in a patient who previously had a number of diagnosed head and neck skin carcinomas, and was diagnosed as primary squamous breast carcinoma. As a first case we present a 85-year-old female with a two months history of swelling of the left breast under the mammilla. The second one, a 69-year-old female presented to our hospital in January 2008 with a two months history of a lump in the lower outer region of the left breast and enlarged lymph nodes in left axillary region. Fine needle aspiration cytology (FNAC) of the breast was performed in order to diagnose the exact type of both tumours. This methodology was found important in diagnosis, but in both cases showed certain limitations in diagnosing such rare tumors. The final diagnoses were determined after carefully synthesizing the histological findings and clinical data. Careful and accurate classification of these tumors is necessary. A detailed analysis of their biological behavior and response to the therapy is necessary in order to formulate definite recommendations in managing these patients/diseases.