Low grade urothelial carcinoma mimicking basal cell hyperplasia and transitional metaplasia in needle prostate biopsy.

PURPOSE: The vast majority of urothelial carcinomas infiltrating the bladder are consistente with high-grade tumors that can be easily recognized as malignant in needle prostatic biopsies. In contrast, the histological changes of low-grade urothelial carcinomas in this kind of biopsy have not been studied. MATERIALS AND METHODS: We describe the clinicopathologic features of two patients with low-grade bladder carcinomas infiltrating the prostate. They reported dysuria and hematuria. Both had a slight elevation of the prostate specific antigen and induration of the prostatic lobes. Needle biopsies were performed. At endoscopy bladder tumors were found in both cases. RESULTS: Both biopsies showed nests of basophilic cells and cells with perinuclear clearing and slight atypia infiltrating acini and small prostatic ducts. The stroma exhibited extensive desmoplasia and chronic inflammation. The original diagnosis was basal cell hyperplasia and transitional metaplasia. The bladder tumors also showed low-grade urothelial carcinoma. In one case, the neoplasm infiltrated the lamina propria, and in another, the muscle layer. In both, a transurethral resection was performed for obstructive urinary symptoms. The neoplasms were positive for high molecular weight keratin (34BetaE12) and thrombomodulin. No metastases were found in either of the patients, and one of them has survived for five years. CONCLUSIONS: The diagnosis of low-grade urothelial carcinoma in prostate needle biopsies is difficult and may simulate benign prostate lesions including basal cell hyperplasia and urothelial metaplasia. It is crucial to recognize low-grade urothelial carcinoma in needle biopsies because only an early diagnosis and aggressive treatment can improve the prognosis for these patients.

Pseudohyperplastic Adenocarcinoma With Foamy Changes in Needle Prostate Biopsy and Prostatectomy.

Pseudohyperplastic adenocarcinoma (PHA) with foamy changes is composed of neoplastic glands that show a cytoarchitectural combination of both neoplasms. However, none of the previously reported cases have shown typical areas of foamy or PHA. We report on the clinicopathological characteristics of 5 cases consisting predominantly of pseudohyperplastic and foamy adenocarcinomas. In several histological fields, this neoplasm mimicked hyperplastic nodules or prostatic adenosis because they showed the nodular pattern of the PHA and the inconspicuous cytological atypia of foamy gland carcinoma. Four cases had a Gleason score of 6. In the prostatectomies, the neoplasm was limited to the prostatic gland. The evolution has been favorable in all patients after 3 years of follow-up, on average. The cases reported herein demonstrate that PHA and foamy adenocarcinoma may be associated and occasionally show overlapping histological criteria. The PHA with foamy changes must be distinguished from conventional foamy adenocarcinoma and PHA because it can closely resemble hyperplastic glands mainly in needle prostatic biopsy.

Low grade urothelial carcinoma mimicking basal cell hyperplasia and transitional metaplasia in needle prostate biopsy

ABSTRACT Purpose The vast majority of urothelial carcinomas infiltrating the bladder are consistent with high-grade tumors that can be easily recognized as malignant in needle prostatic biopsies. In contrast, the histological changes of low-grade urothelial carcinomas in this kind of biopsy have not been studied. Materials and Methods We describe the clinicopathologic features of two patients with low-grade bladder carcinomas infiltrating the prostate. They reported dysuria and hematuria. Both had a slight elevation of the prostate specific antigen and induration of the prostatic lobes. Needle biopsies were performed. At endoscopy bladder tumors were found in both cases. Results Both biopsies showed nests of basophilic cells and cells with perinuclear clearing and slight atypia infiltrating acini and small prostatic ducts. The stroma exhibited extensive desmoplasia and chronic inflammation. The original diagnosis was basal cell hyperplasia and transitional metaplasia. The bladder tumors also showed low-grade urothelial carcinoma. In one case, the neoplasm infiltrated the lamina propria, and in another, the muscle layer. In both, a transurethral resection was performed for obstructive urinary symptoms. The neoplasms were positive for high molecular weight keratin (34BetaE12) and thrombomodulin. No metastases were found in either of the patients, and one of them has survived for five years. Conclusions The diagnosis of low-grade urothelial carcinoma in prostate needle biopsies is difficult and may simulate benign prostate lesions including basal cell hyperplasia and urothelial metaplasia. It is crucial to recognize low-grade urothelial carcinoma in needle biopsies because only an early diagnosis and aggressive treatment can improve the prognosis for these patients.