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.