Intracystic papillary carcinoma of the breast in a male patient diagnosed by core needle biopsy: a case report.

We report a case of intracystic papillary carcinoma (IPC) of the breast in a 71-year-old man in whom diagnosis was made by core needle biopsy. He came to our hospital complaining of a left subareolar mass. Imaging diagnosis was a cyst with an intracystic component. Since aspiration biopsy cytology was interpreted as a borderline lesion, the decision was made to proceed with core needle biopsy. Pathological examination of the specimen revealed the intracystic component to be non-invasive papillary carcinoma. So the patient underwent simple mastectomy without axillary node biopsy. From the final pathological result, no invasion was identified.