Intracystic invasive papillary carcinoma of the male breast with analyses of loss of heterozygosity on chromosome 16q.

A 64-year-old man noticed a right subareolar mass in May 2005. On physical examination, an oval-shaped, well-circumscribedthe tumor (6.0 x 5.5 cm in size) was located just beneath the right nipple. The tumor was elastic, firm and freely movable. Neither axillary nor supraclavicular lymph nodes were palpable. Mammography demonstrated a 5 x 5-cm, relatively distinct and dense mass without microcalcifications or spiculations. There were no findings of concurrent gynecomastia. Ultrasonography revealed a large multilocular cyst with a mural hypoechoic protruding lesion exhibiting wide-based morphology with an irregular margin. On contrast-enhanced computed tomography, the inner lesion enhanced, but direct invasion of the tumor to the major pectoral muscle was not found. An intracystic papillary lesion, possibly papillary carcinoma, was suspected. In December 2007, wide excision of the tumor was performed. On histopathological examination, the tumor had a papillary pattern with a small cribriform component in the cystic wall with microinvasion of the stroma. Marginal status was negative. The final diagnosis of the disease was a microinvasive intracystic papillary carcinoma of low grade without axillary lymph node metastases. Immunohistochemically, estrogen receptor and progesterone receptor were both positive, but negative for HER-2 protein. No LOH on 16q could be detected. The prognosis of the disease was unclear; however, the malignant potential of this condition may be more clearly determined by studying the LOH on chromosome 16q.