Objective: Apocrine carcinoma is a rare and histologically distinct type of invasive breast carcinoma. Method: The patient, a 73 years-old woman was admitted to the hospital for a tumor mass in the upper internal quadrant of the left breast. Tissue fragments from the quadrantectomy specimen were routinely processed by paraffin embedding. For the immunohistochemical (IHC) study we used the following antibodies: CK7, androgen receptors (AR), estrogen receptors (ER), progesterone receptors (PR), high molecular weight cytokeratin (HMWCK), p63, gross cystic disease fluid protein-15 (GCDFP-15), En Vision system, visualization with diaminobenzidine. Results: The gross examination revealed a nodular, well delineated mass of 2,5/2,7/3 cm, firm, gray-beige with areas of necrosis on cut section. Microscopically, the tumor had a predominantly solid, partially cystic and less tubular growth pattern. The tumor cells had abundant eosinophilic granular cytoplasm and pleomorphic high-grade nuclei. A small tumor contingent presented squamoid features. IHC stains showed the following profile: CK7+, AR+, GCDFP-15+, ER-, PR-, p63/HMWCK + (focal/zonal). A diagnosis of high-grade infiltrating apocrine carcinoma with squamous differentiation was established. Conclusion: There are only a few cases of apocrine carcinoma on record and our case is even more special because of his peculiar aspect, the squamous differentiation.