Verumontanum mucosal gland hyperplasia in prostatic needle biopsy specimens. A mimic of low grade prostatic adenocarcinoma.

The histologic features of five cases of verumontanum mucosal gland hyperplasia (VMGH) in prostatic needle biopsy specimens are reported. All cases were initially reviewed in consultation by one of two of the authors (JIE or TMW) and in all cases, the submitted differential diagnosis included low grade adenocarcinoma. In all cases, VMGH was characterized by a relatively well-circumscribed collection of closely packed glands, and was typically observed immediately subjacent to urothelium. A basal cell layer was readily identifiable in routine hematoxylin-and-eosin-stained sections. The luminal contents of the verumontanum mucosal glands were distinctive and consisted of lamellated eosinophilic concretions typical of corpora amylacea, as well as unique orange-red concretions that were commonly fragmented. The histologic features of VMGH are characteristic and allow distinction from other small glandular proliferations of the prostate including nephrogenic adenoma, adenosis (atypical adenomatous hyperplasia), and low grade adenocarcinoma.