Cystic Hypersecretory Carcinoma
This variant of duct carcinoma was first described in 1984 (1). The majority of cases have been intraductal carcinomas. A benign proliferative lesion that resembles cystic hypersecretory carcinoma (CHC) has been termed cystic hypersecretory hyperplasia (CHH) (2). The age distribution of CHC ranges from 34 to 79 years, with a mean of 56 years (2). The presenting symptom is usually a palpable mass. Mammography in one case revealed a prominent ductal pattern and an irregular density in the breast (3). The mammogram in a patient with cystic hypersecretory intraductal carcinoma revealed “heterogeneous dense breast tissue with no indication of a mass or microcalcifications, and sonography revealed multiple small aggregated, anechoic cysts with good through transmission” (4). Two patients with invasive CHC were reported to have spiculated masses with calcifications on mammography (5).
Among 10 tumors studied biochemically, 8 had negative levels of estrogen and progesterone receptors. Two specimens were positive for both receptors. In situ and invasive components have been reported to be Her2/neu-positive (6).
The distinctive feature of CHC is the presence of numerous cysts measuring up to 1.5 cm. Secretion within cysts has been described as grossly sticky, mucinous, gelatinous, or as resembling thyroid colloid. It is usually not possible to distinguish grossly between cystic hypersecretory intraductal carcinoma and CHH. An invasive component associated with CHC produces a distinct, solid mass.
The microscopic hallmark of a cystic hypersecretory lesion is the presence of cysts, which contain eosinophilic secretion that resembles thyroid colloid (Fig. 19.1). The homogeneous and virtually acellular secretion often retracts from the surrounding epithelium, resulting in a smooth or scalloped margin duplicating the contour of the epithelial proliferation. Folds, linear cracks, or small punched-out holes occur in the secretion. No appreciable differences are present in the character of the secretion between CHC and CHH. Positive reactions for carcinoembryonic antigen, alpha-lactalbumin, periodic acid-Schiff (PAS), and mucin have been observed in the cyst contents that are consistently negative for thyroglobulin. Disruption results in spillage of cyst contents into the stroma, eliciting an intense inflammatory reaction consisting of lymphocytes and histiocytes.