Case 1. A 55 year old woman had a core biopsy of a mass in the skin of her left breast. She also had skin lesions on her abdomen.
Case 1 Diagnosis: Metastatic ovarian carcinoma.
Case 2. A 75 year old woman presented with a left breast mass. An ultrasound-guided core biopsy specimen was obtained.
Case 2 Diagnosis: Invasive micropapillary carcinoma.
Discussion: These cases illustrate similar histopathology of two different tumor types, emphasizing the importance of clinical history and presentation. The first patient had a history of ovarian carcinoma, and the presence of multiple skin lesions, including skin of abdomen, supports the diagnosis of metastatic ovarian carcinoma. The immunophenotype (WT1 positive) is also supportive of ovarian origin, however without the history a pathologist might not consider performing immunohistochemistry.
The second tumor was a single breast mass, and in addition to the invasive micropapillary carcinoma, intermediate grade ductal carcinoma in situ was also present. Immunohistochemical studies were not performed, but the history and clinical presentation, along with the presence of DCIS support breast origin.