Sonographic findings in a patient with cystic hypersecretory duct carcinoma of the breast.

In this report, we describe a case of a rare form of intraductal carcinoma of the breast known as cystic hypersecretory duct carcinoma in a 49-year-old woman with a palpable mass and no history of breast disease. Mammography showed heterogeneous dense breast tissue with no definite abnormally increased density or microcalcifications. Gray-scale sonography detected multiple small aggregated, anechoic cysts with good through-transmission in the upper outer quadrant of the left breast, corresponding to the location of the palpable mass. The patient underwent an excision biopsy, and histopathologic examination of the surgical specimen revealed multiple cysts of different size containing an eosinophilic material resembling thyroid colloid. The locations of the cysts corresponded to those of the anechoic cysts detected on sonography. The epithelium lining the cysts showed micropapillary growth consistent with a diagnosis of cystic hypersecretory duct carcinoma. The mammographic and sonographic findings in this case differed somewhat from those reported previously for this rare form of breast carcinoma. Because the imaging findings and low-power microscopic appearance of the mass in our patient's case closely resembled those of some benign breast lesions, we recommend careful differentiation of this type of lesion using high-power microscopy during histopathologic evaluation.