Invasive micropapillary carcinoma of the breast in a male patient: Report of a case.
BACKGROUND
We report a rare case of invasive micropapillary carcinoma in the male breast.


METHODS
A 63-year-old man was referred to our hospital for investigation of a left breast tumor, which could be palpated in the upper lateral quadrant of the left nipple-areola complex. The tumor invaded the areola skin. Ultrasonography showed a 14.8×15.0×12.4mm low echoic mass, with an irregular lobulated border. Core needle biopsy indicated invasive ductal carcinoma, but the subtype could not be accurately determined. Mastectomy with axillary lymph node dissection was performed. Pathological examination indicated invasive micropapillary carcinoma, no lymph node metastasis, and a nuclear grade of 2. Immunohistochemical examination showed positive staining for estrogen and progesterone receptors, but negative staining for HER2. The Ki67 index was 5%. Tamoxifen was administered, and recurrence has not been noted for 1 year.


CONCLUSIONS
Women's IMPC generally shows a high HER2 positivity rate. However, HER2 positivity was noted in only 1 male patient with IMPC (14%) according to our literature review. Furthermore, in all cases of the mixed type that were reviewed, IMPC was associated with papillotubular carcinoma. These findings may be specific to IMPC in male patients.


CONCLUSIONS
IMPC is associated with a high rate of lymph node metastasis or recurrence and advanced vessel invasion, aggressive adjuvant chemotherapy following surgical resection should be selected for patients with IMPC.
Ehime Rosai Hospital, Department of Surgery and Department of Pathology, Minamikomatsubara-cho 13-27, Niihama, Ehime 792-8550, Japan. Electronic address: ttsushimi@yahoo.co.jp.
Takaaki
T
Tsushimi
Hirohito
H
Mori
Takasuke
T
Harada
Yoshitaka
Y
Ikeda
Hiromi
H
Ohnishi
Invasive macropapillary carcinoma; Male; Tamoxifen