DIAGNOSTIC LIMITS IN PRECURSOR LESIONS OF PROSTATIC-CANCER

Objective: Among prostatic lesions with atypical features, atypical ad enomatous hyperplasia (AAH; microglandular proliferation with bland nu clei), and prostatic intraepithelial neoplasia (PIN; cellular atypia i n preexisting large ducts and acini) are considered precursors of pros tatic cancer, but these lesions are a continuum from the normal prosta te to prostatic cancer. The objective of the paper is to bring attenti on to the pitfalls in the diagnosis of both lesions. Material and Meth ods: To describe the diagnostic limits in AAH and PIN, we used the lit erature information and our 76 cases of AAH and 169 patients with PIN at prostatic core biopsy. Conclusions: In the majority of cases, AAH a ppears in the transition zone and it is necessary to be very strict in the diagnosis in order to avoid confusion with microglandular BPH. On e of the controversies is the biologic significance of prominent nucle oli in the AAH. Although the association of AAH with cancer is relativ ely scant, we have a higher incidence of cancer in cases with AAH than in classic BPH and we recommend complete study of the surgical specim en. Low-grade PIN does not need to be reported, but high-grade PIN sho uld be and close follow-up is recommended if we find an isolated high- grade PIN. Because the clinical implications of high-grade PIN are so important, pathologists must be sure of the diagnosis avoiding interpr etation in inflammatory areas. The high-molecular-weight cytokeratins may be useful in some cases, when the diagnosis of adenocarcinoma vs. high-grade PIN is seriously considered.