Xanthogranulomatous Prostatitis, a Rare Prostatic Entity.

There are several benign prostatic pathologies that can clinically mimic a prostate adenocarcinoma. Xanthogranulomatous prostatitis is a benign inflammatory condition of the prostate and a rare entity. A 47-year old male, with 3 years of lower urinary tract symptoms, with a palpable hypogastric tumor, digital rectal examination: solid prostate, of approximately 60 g. Initial PSA was 0.90 ng/mL. He underwent surgical excision of the lower abdominal nodule and prostatectomy. Histopathology showed xanthogranulomatous prostatitis, without malignancy. Xanthogranulomatous prostatitis is an extremely rare entity that can simulate prostate adenocarcinoma, therefore having a correct histopathological diagnosis is essential.

Introduction

The benign pathologies of the prostate that can mimic a prostatic adenocarcinoma are compromised in six grand groups, and among them we find the inflammatory pathologies. Xanthogranulomatous prostatitis is considered among those pathologies and can clinically behave as a prostatic carcinoma. The first case report and description of this pathology was made in Poland by Miekoś et al in 1986, and 15 cases have been reported in worldwide literature since, the most recent ones in India and South Korea. In this article, we present a case report of a patient with clinical suspicion of prostatic carcinoma and histopathological report of xanthogranulomatous prostatitis.

Case presentation

47 year old male patient, who started 3 years ago of lower urinary tract symptoms, urinary incontinence, urgency, reduced urinary stream, frequency 8/4, and acute urinary retention multiple times. As comorbidity the patient has diagnosis of chronic kidney disease on hemodialysis as renal replacement therapy with 3 sessions per week. Digital rectal examination, found a hard prostate, of approximately 60 g, abdominal tenderness that presented with a tumor in the lower abdomen, mobile, not fixed. Previously presented with bulbar urethral stenosis and a history of internal urethrotomy and transurethral resection of the prostate, with initial pathology report of benign prostatic hyperplasia.

Afterward our patient continued to have lower urinary tract symptoms and he underwent resection of tumor and open prostatectomy, with the following findings: 3 × 3 cm tumor in the bladder dome, hard prostate and multiple fetid clots inside the bladder. He had an initial prostatic specific antigen of 0.94 ng/mL in September 2012 and his last prostatic specific antigen dated 01/27/15 was 0.40 ng/mL. Currently our patient has spontaneous micturition and still has renal replacement therapy with hemodialysis.

The histopathological report showed the lower abdomen tumor was a bladder leiomyoma and prostate with xanthogranulomatous prostatitis, with glands of multiple sizes, abundant fibrous stroma with a chronic inflammatory infiltrate rich with lymphocytes, plasma cells and histiocytes and no evidence of malignancy.

Discussion

Granulomatous lesions of the prostate remain rare and their classification is controversial. Some etiologic agent has been proposed for granulomatous prostatitis including some fungi, Treponema pallidum and Mycobacterium tuberculosis. Non-specific granulomatous prostatitis remains the most frequent diagnosis in terms granulomatous prostatitis.

In one study, an autoimmune origin for these conditions was suggested.

In xanthogranulomatous prostatitis, histiocytes are observed in large amounts in an inflammatory infiltrate, that is accompanied by multiple lymphocytes and plasma cells. This specific feature, the histiocytes, cause confusion and may be diagnosed as prostate adenocarcinoma with hypernephroid pattern (Gleason 4B).

Generally this condition, xantogranulomatosis, is observed more frequently in the kidney and the gallbladder and very rarely in the prostate. The age of diagnosis is usually the sixth decade of life but it has a wide range. Clinically they have low obstructive urinary symptoms and digital rectal examination, with a palpable hard prostate and which may make differentiation of prostatic carcinoma difficult. It has been observed in some studies a range of prostatic specific antigen from 0.5 ng/mL to 150 ng/mL. In the present study, the patient prostatic specific antigen was elevated and its range was 0.40 ng/mL to 90 ng/mL with an average of 0.65 ng/mL.

Currently no imaging study allows for differentiation between this condition and prostatic adenocarcinoma. The diagnosis is histopathologic (Figure 1, Figure 2).

Figure 1

Xanthogranulomatous prostatitis.

Figure 2

Histiocytes.

Conclusion

Xanthogranulomatous prostatitis is an extremely rare entity and can simulate either clinically and/or biochemically a prostatic adenocarcinoma. Precise histopathologic diagnosis has and will have the outmost importance for differentiating benign from malignant prostatic pathology.

Conflicts of interest

None.