Isolated prostate tuberculosis: A rare condition

Abstract

Tuberculosis remains a global health threat, notably with a considerable burden of extrapulmonary cases. Prostate tuberculosis stands out as a rare and challenging diagnosis, often resulting in substantial management delays. In this report, we present the case of a 55-year-old man in whom initial suspicion of prostate cancer resulted in the diagnosis of prostate tuberculosis. The diagnostic methods, progressive features, and therapeutic tools of this rare condition are discussed.

1. Introduction

Tuberculosis (TB) is reasserting its position as the primary cause of death from a single infection, surpassing COVID-19, with an incidence rate of 134 cases per 100,000 inhabitants and an estimated mortality of 1.6 million deaths annually.¹ Globally, 30–40 % of tuberculosis cases are extrapulmonary, rising to 50 % in endemic regions.² Despite this prevalence, prostate tuberculosis (PrTB) remains a rare and poorly understood entity, leading to diagnostic and therapeutic delays.² In this report, we present a case of PrTB diagnosed in a patient with suspicion of prostate cancer.

2. Case presentation

We present the case of a 55-year-old man with no tuberculosis-related or other significant medical history. He presented with persistent dysuria and pollakiuria over several months. He reported no weight loss or respiratory symptoms. Digital rectal examination (DRE) found an enlarged and soft prostate, with no palpable nodules. The rest of physical examination, including an assessment of lymph nodes and genital organs, revealed no anomalies.

Alpha-blocker therapy was initiated using tamsulosin, leading to partial alleviation of symptoms. A prostate-specific antigen (PSA) test indicated an initial level of 4.1 ng/mL, which subsequently rose to 6.2 ng/mL. Prostate MRI identified a Pi-Rads 4 transition zone lesion (Fig. 1). Histopathological examination of the prostate biopsy revealed granulomas with central caseous necrosis, indicative of tuberculous prostatitis (Fig. 2).

Fig. 1.

Axial T2-weighted image of a multiparametric prostate MRI showing a 13 mm noncircumscribed, homogenous, moderately hypointense lesion (slide a) with markedly hypointense signal on ADC map (slide b).

Fig. 2.

Pathology of prostate biopsy core showing multiple epithelioid granulomas (black arrows) with central necrosis (black asterisk), stained with H & E (Magnification: x10, slide a; x40, slide b).

Chest X-ray showed no signs of pulmonary tuberculosis, and renal ultrasound confirmed normal kidney morphology without dilation. Urine acid-fast bacilli (AFB) staining was negative. A diagnosis of isolated prostate tuberculosis was established. The patient had no known comorbidities, and assessments revealed no immunocompromising conditions, such as diabetes or HIV co-infection.

A two-month quadritherapy, consisting of isoniazid, rifampicin, pyrazinamide, and ethambutol, was initiated, followed by a four-month maintenance phase with isoniazid and rifampicin. The patient exhibited good tolerance to the regimen, and significant resolution of urinary symptoms was observed within two months of anti-tuberculous therapy.

3. Discussion

In Morocco, an endemic region where extrapulmonary tuberculosis (EPTB) accounts for 49 % of new cases, genitourinary tuberculosis, particularly isolated prostatic localization, remains an extremely uncommon occurrence.³ It typically emerges from the hematogenous dissemination of Mycobacterium tuberculosis, commonly originating from a pulmonary site, whether the infection is active or latent.² Kulchavenya reported a concurrent incidence of renal tuberculosis in 79 % of PrTB patients.⁴ While sexual transmission is unusual, the coexistence of HIV increases the risk of genital tuberculosis in sexually active men.⁴ Instances of PrTB and epididymitis have been documented following intravesical Bacillus Calmette-Guérin (BCG) immunotherapy for bladder tumors.¹ Additional comorbidities such as diabetes, immunosuppressive drug use, as well as smoking and alcohol consumption contribute to the epidemic spread of tuberculosis.¹

Prostate tuberculosis frequently escapes early diagnosis due to its insidious clinical presentation, marked by two stages of progression. The initial infiltrative stage typically manifests with nonspecific symptoms, including lower urinary tract symptoms such as dysuria or pollakiuria, perineal pain associated with chronic pelvic pain syndrome, or hematospermia.⁴ Additional manifestations may involve erectile dysfunction and infertility.⁴ The cavernous stage, commonly considered an incurable form, manifests later and typically presents with pyospermia, pyuria, or perineal fistula.⁴

In the infiltrative stage, a DRE typically reveals a nodular enlargement of the prostate. These findings may trigger suspicion of prostate cancer, especially if the PSA level is elevated,⁴ prompting further investigation with prostate MRI followed by a prostatic biopsy. The histological examination of the prostate biopsy serves as a crucial diagnostic tool for early-stage PrTB, marked by the presence of epithelioid cell granuloma with caseating necrosis.² However, the existence of prostatic cavities should be investigated through MRI.⁴ Their presence, which is pathognomonic for cavernous PrTB, should be confirmed by retrograde urethrography. These findings would contraindicate a biopsy to avoid potentially fatal fulminant dissemination.^4,5 Ultrasound and CT play limited role in identifying PrTB, but may detect signs of renal or urinary tract tuberculosis given the frequent association.^2,4

Various microbiological examinations are employed to confirm the diagnosis, including direct examination for AFB using Ziehl–Neelsen or auramine staining, culture on specific media, PCR, and GeneXpert assay. These tests are conducted on prostatic specimens (post-prostatic massage urine and ejaculate, post-ejaculation urine), urinary specimens (first-void urine for three consecutive days), and tissue or pus samples.^2,5 Additionally, screening for pulmonary TB and HIV co-infection is imperative.⁴ In selected patients with strong clinical suspicion of TB without microbiological evidence, considering the diagnosis is plausible in case of favorable progression under empirical treatment.²

The management of PrTB primarily involves anti-tuberculous drugs, following the classic six-month scheme.⁵ The increasing prevalence of multidrug-resistant tuberculosis (1.9 % of new cases and 10 % in previously treated cases in Morocco) emphasizes the need for individualized therapeutic regimens.^3,5 In the absence of specific recommendations, surgical interventions are limited to drainage procedures for prostatic abscesses and, when necessary, transurethral resection to address lower urinary tract symptoms.^2,4

4. Conclusion

Despite ongoing efforts to combat tuberculosis, it remains a global public health challenge. PrTB is an exceptionally rare condition that can lead to cavernous prostatitis, significantly impacting the patients’ quality of life. Its nonspecific presentation, particularly in early stages, contributes to delayed diagnosis and management. Recognizing PrTB, especially in individuals coming from or residing in endemic areas, is crucial for early diagnosis and preventing unfavorable outcomes.

CRediT authorship contribution statement

Omar Bellouki: Writing – review & editing, Writing – original draft, Conceptualization. Abdelmounim Boughaleb: Writing – original draft. Ilyas Soufiani: Writing – review & editing, Conceptualization. Imad Boualaoui: Writing – review & editing, Visualization, Methodology. Hachem El Sayegh: Writing – review & editing, Validation, Supervision. Yassine Nouini: Validation, Supervision, Formal analysis, Conceptualization.