Abstract
Male breast cancer is a rare disease in the male breast whereas gynecomastia is quite common. An elevation of the estrogen-to-androgen ratio increases the risk of both of these diseases. However, a connection between gynecomastia and subsequent breast cancer development is controversial and unclear. Imaging studies including mammography and ultrasound provide valuable information in leading to a correct diagnosis. Traditionally, intracystic papillary carcinoma, also known as encapsulated papillary carcinoma, has been considered a form of ductal carcinoma in situ. Recent immunohistochemical studies, demonstrating an absence of myothelium, in many cases would be more compatible with the diagnosis of invasive malignancy. However, intracystic papillary carcinoma holds a favorable prognosis with local therapy alone. We report a case of intracystic papillary carcinoma in a male patient with long-standing gynecomastia diagnosed eight years prior by mammography. The patient presented with a breast lump on both occasions. Current work-up consisted of both mammography and ultrasound. Ultrasound provided key information revealing a complex mass requiring further evaluation. Ultrasound-guided core needle biopsy revealed intracystic papillary carcinoma with confirmation upon surgical excision.