Abstract

Breast cancer is one of the most common malignancies that can lead to cutaneous metastasis. Dermatopathologists often play an important role in the diagnosis of breast cancer metastasis to the skin. Rarely, dermatopathologists render a histopathologic diagnosis of primary breast cancer. We present a case of metastatic breast adenocarcinoma in a male patient. A 51-year-old male was admitted to the ICU after presenting to the emergency department with altered mental status in the setting of critical anemia with a hemoglobin of 1.9 g/dL. Examination revealed a 14 x 12 cm ulcerated, fungating tumor occupying the entirety of the left breast. A 4 mm punch biopsy from the edge of the mass showed cords of atypical cells infiltrating the mid to deep dermis positive for CK7, GATA3, ER and PR. CK20, P40, p63 and TTF-1 stains were negative. HER2/NEU immunoperoxidase stain was negative. CA-15-3 was elevated at 75 U/mL. Taken together, he was diagnosed with primary left breast ductal adenocarcinoma, grade 2 with subsequent visceral metastases to the bones, lymph nodes, and lungs. While male breast cancer makes up less than 1% of all breast cancers, its incidence has been increasing worldwide. Recognition of the unique clinical and histologic findings of primary breast carcinoma is important to avoid delay in the diagnosis and initiation of appropriate treatment.