Preoperative cytological diagnosis of mucinous carcinoma (MC) of male breast

We report a case of MC diagnosed preoperatively on the basis of cytology findings. A 60-year-old male with slowly enlarging, subareolar lump in left breast was referred for fine needle aspiration cytology (FNAC) presuming it to be gynecomastia. He had no other complaints, no history of any major illness in the past. The breast swelling was 1 cm × 1 cm, well-defined, mobile and firm in consistency. Cytology smears revealed moderate cellularity in the background of abundant mucinous material and chicken wire-like blood vessels [Figure 1a]. The cells were seen in groups, dispersed individually, showed moderate cytoplasm, large, round to oval eccentric nuclei with regular nuclear membrane, granular chromatin and one to two prominent nucleoli [Figure 1b]. Cytodiagnosis of MC was offered. Preoperative mammography and sonography revealed lobulated, hyperechoic mass in the central part of the left breast. On extensive clinical and radiological study, no mass lesion was found at any other body site. The patient’s modified radical mastectomy specimen showed a subareolar glistening white, firm tumor, of size 1.5 cm × 1.5 cm, along with six subcentimetric lymph nodes and axillary fat. Histopathology sections revealed malignant cells arranged in groups and cords within pools of mucin. Lymph nodes did not show evidence of metastasis. The diagnosis of primary MC of the breast was confirmed.