Abstract

Objective: Breast carcinoma in men represents 1% of all breast cancers. The micropapillary carcinoma (MPC) of the breast is a morphologically distinctive form accounting for 2.7% of ductual carcinoma in which the tumor cells are arranged in morule-like clusters. A pure MPC of the breast is very rare. This report describes a pure micro papillary carcinoma in a 36-year old man, with clinical, pathological and immunohistochemical features.

Methods: We present a case of this rare type of breast cancer diagnosed in a male patient and summarize the current literature to date. The patient presented with a painless mass measuring 1 cm in great diameter adhering to superficial and deep planes. A microbiopsy was performed and the final histopathology revealed a pure MPC of the male breast in more than 50% of tumor’s volume. On immunohistochemical investigations of the specimen, tumor’s cells stained for GCDFP15 and showed high expression of estrogen, progesterone antibodies. We had completed by lumpectomy with axillary dissection which found 14 lymph nodes including 2 metastatic lymph nodes.

Results: The MPC differs histologically from conventional papillary carcinoma of the breast, which typically exhibits a complex arborescent growth pattern within cystically dilated duct-line space. A secondary MPC of the breast must be researched as a differential diagnosis of primary MPC, especially micropapillary variant of transitional carcinoma of the bladder and MPC of the lung. Immunohistochemically, the positivity of GCDFP-15 in breast cancers and the positivity of TTF-1 in lung cancers are useful in distinguishing them.

Conclusion: MPC is a special subtype of invasive ductal carcinoma with an aggressive nature. Despite the small number of studies, MPC of the breast is undoubtedly not rare. Recognition of this relatively rare entity is important in predicting metastasis to lymph nodes and distant sites regardless of tumor size. Axillary and distant metastasis should be evaluated to determine the therapeutic strategy.

Keywords: Micropapillary carcinoma; Breast cancer; Male; Cytology; Immunohistochemistry; Pseudopapillary; Tamoxifen