Morphologic Criteria for the Diagnosis of Prostatic Adenocarcinoma in Needle Biopsy Specimens

Context.—The diagnosis of prostate adenocarcinoma in needle core biopsy specimens is based on multiple diagnostic criteria and supportive features, most of which have been defined mainly from observations in transurethral resection and prostatectomy specimens. There is little information on the frequency with which diagnostic and supportive features of prostate cancer occur within benign glands. The few reports dealing with diagnostic criteria of cancer in needle biopsies have been largely confined to analysis of selected cases that posed particular diagnostic difficulty. Objective.—To analyze the frequency with which numerous diagnostic or supportive features of prostate cancer occur in an unselected, consecutively performed series of 18-gauge prostate needle biopsy specimens. Design.—Two hundred fifty consecutive 18-gauge prostate needle biopsy specimens (150 malignant and 100 benign) were evaluated, using hematoxylin-eosin–stained histologic sections. Results.—The frequency of the histologic features in malignant and benign glands was as follows: prominent nucleoli (94% and 25% of malignant and benign specimens, respectively), marginated nucleoli (88% and 7%), multiple nucleoli (64% and 0%), blue-tinged mucinous secretions (52% and 0%), intraluminal crystalloids (40.6% and 1%), intraluminal amorphous eosinophilic material (86.7% and 2%), collagenous micronodules (2% and 0%), glomerulations (15.3% and 0%), perineural invasion (22% and 0%), retraction clefting (38.6% and 7%), and invasion of fat (0.7% and 0%). Conclusions.—Since not all diagnostic or supportive features of cancer are evident in any single case of cancer, particularly in needle biopsy specimens in which sampling is limited, awareness of these data would be helpful in the assessment of small foci of atypical glands being considered for cancer.