Intraductal Carcinoma of the Prostate

Abstract

Intraductal carcinoma of the prostate (IDC-P) is characterized by malignant cells expanding the lumen of prostatic ducts and acini (Figure 1) (1). The basal cells are completely or partially preserved (Figure 2). The malignant cells filling the gland cause trabecular, cribriform, micropapillary or solid pattern (2,3,4,5). The glands with intraductal carcinoma are more than twice the diameter of normal peripheral zone glands and may show branching typically at the right angles (Figure 3). The contour of the glands is smooth in contrast to benign and high-grade prostatic intraepithelial neoplasia (H-PIN). There may be comedonecrosis (2). The cells show generally two different populations. The outer layer cells are pleomorphic with marked nuclear atypia and six times larger than benign nuclei. They are mitotically active and stain poorly for prostate specific antigen (PSA) immunohistochemically (1). The inner group cells are small (Figure 3). They are monomorphic cuboidal cells with abundant cytoplasm and strong PSA staining. There may be extracellular mucin (Table 1). The differential diagnosis of IDC-P includes cribriform H-PIN, invasive cribriform adenocarcinoma, ductal adenocarcinoma, and intraductal spread of urothelial carcinoma. H-PIN lacks solid and cribriform patterns, comedonecrosis, two different cell populations, and marked nuclear enlargement. Ductal adenocarcinoma has papillary structures with fibrovascular cores, and basal cells are usually absent. Cribriform adenocarcinoma shows irregular and invasive borders and absence of basal cells. Urothelial carcinoma

Keywords

• Prostate
• intraductal
• carcinoma
• carcinoma in situ