Question: Missouri Subscriber Answer: If the surgeon provides some documentation regarding why he thought the breast mass needed to be removed, such as an abnormal fine needle aspiration or biopsy, you could code the procedure as 19303. But you don't mention any intraoperative or prior diagnoses. A surgeon would not typically perform a mastectomy without first getting biopsy results, so this would be an unusual scenario. Without further documentation, it appears that the surgeon performed the mastectomy for gynecomastia (611.1, Hypertrophy of breast), even if he didn't know the final diagnosis for sure prior to surgery. Payers rarely cover 19300, because they consider it a cosmetic procedure.