Chronic prostatitis alters the prostatic microenvironment and accelerates preneoplastic lesions in C57BL/6 mice

BACKGROUND: Chronic prostatitis has been supposed to be associated with preneoplastic lesions and cancer development. The objective of this study was to examine how chronic inflammation results in a prostatic microenvironment and gene mutation in C57BL/6 mice. METHODS: Immune and bacterial prostatitis mouse models were created through abdominal subcutaneous injection of rat prostate extract protein immunization (EAP group) or transurethral instillation of uropathogenic E. coli 1677 (E. coli group). Prostate histology, serum cytokine level, and genome-wide exome (GWE) sequences were examined 1, 3, and 6 months after immunization or injection. RESULT: In the EAP and E. coli groups, immune cell infiltrations were observed in the first and last months of the entire experiment. After 3 months, obvious proliferative inflammatory atrophy (PIA) and prostatic intraepithelial neoplasia (PIN) were observed accompanied with fibrosis hyperplasia in stroma. The decrease in basal cells (Cytokeratin (CK) 5+/p63+) and the accumulation of luminal epithelial cells (CK8+) in the PIA or PIN area indicated that the basal cells were damaged or transformed into different luminal cells. Hic1, Zfp148, and Mfge8 gene mutations were detected in chronic prostatitis somatic cells. CONCLUSION: Chronic prostatitis induced by prostate extract protein immunization or E. coli infection caused a reactive prostatic inflammation microenvironment and resulted in tissue damage, aberrant atrophy, hyperplasia, and somatic genome mutation.

Inflammatory myofibroblastic tumor of the prostate after transurethral resection of the prostate with negative expression of anaplastic lymphoma kinase: a case report

ABSTRACT CONTEXT: Inflammatory myofibroblastic tumors are a rare type of soft-tissue tumor. Inflammatory myofibroblastic tumors are characterized by rearrangements involving the anaplastic lymphoma kinase gene locus on 2p23. Case Report: We report the case of a 67-year-old Chinese male who presented with dysuria and fever. Magnetic resonance imaging showed an irregular prostatic mass with an isointense signal and obscure boundary. Histopathological evaluation showed that the mass consisted mainly of spindle-shaped cells. Immunohistochemical evaluation showed that the tumor cells were negative for anaplastic lymphoma kinase. CONCLUSIONS: Inflammatory myofibroblastic prostate tumors are rare lesions with unclear etiology. The pathological diagnosis is very important.