MRI findings of granulomatous prostatitis developing after intravesical Bacillus Calmette-Guérin therapy

The role of multiparametric magnetic resonance ımaging in the diagnosis of granulomatous prostatitis mimicking prostate cancer

PURPOSE

Aimed to investigate the role of multiparametric magnetic resonance imaging (mp-MRI) in the diagnosis of granulomatous prostatitis caused by intravesical Bacillus Calmette-Guérin (BCG).

METHODS

In this prospective, single-center study, 10 male patients who were given intravesical BCG due to intermediate- and high-risk bladder cancer were included. Before transurethral resection of bladder tumors (TURB), all patients were evaluated by mp-MRI, serum prostate-specific antigen (PSA), and digital rectal examination (DRE). Serum PSA levels and DRE findings were evaluated before and after intravesical BCG treatment. Prostate mp-MRI was performed for patients with elevated levels of serum PSA and/or with abnormal DRE findings. Then, MRI fusion + systematic prostate biopsy was performed. Demographic data of the patients before and after intravesical BCG were compared.

RESULTS

The average age of the patients was 66.9 years (55-87 years). While PSA was 1.7 ng/ml before intravesical BCG treatment, it was 4.3 ng/ml after intravesical BCG treatment (p = 0.005). PSA density (PSAD) was 0.04 and 0.10 before and after the treatment, respectively (p = 0.012). DRE findings of all patients were normal before the treatment. However, abnormal findings were detected in 80% of them after the treatment (p = 0.008). PI-RADS ≥ 3 lesions were found to be significantly higher in all patients after intravesical BCG (p = 0.004).

CONCLUSION

Granulomatous prostatitis is a rare complication of intravesical BCG. High PSA, abnormal DRE, and PI-RADS ≥ 3 lesions detected after intravesical BCG should suggest granulomatous prostatitis and unnecessary biopsies may be avoided.

Imaging findings in inflammatory disease of the genital organs

This review focuses on inflammatory diseases of female and male genital organs and discusses their epidemiology, pathogenesis, clinical presentation, and imaging findings. The female section covers pelvic inflammatory disease (PID) primarily caused by sexually transmitted infections (STIs) that affect the uterus, fallopian tubes, and ovaries. Unusual causes such as actinomycosis and tuberculosis have also been explored. The male section delves into infections affecting the vas deferens, epididymis, testes, prostate, and seminal vesicles. Uncommon causes such as tuberculosis, and Zinner syndrome have also been discussed. In addition, this review highlights other conditions that mimic male genital tract infections such as vasculitis, IgG4-related diseases, and sarcoidosis. Accurate diagnosis and appropriate management of these inflammatory diseases are essential for preventing serious complications and infertility. Imaging modalities such as ultrasound, magnetic resonance imaging, and computed tomography play a crucial role in diagnosis. Understanding the diverse etiologies and imaging findings is vital for the effective management of inflammatory diseases of the genital organs.

Multiparametric magnetic resonance imaging for the differential diagnosis between granulomatous prostatitis and prostate cancer: a literature review to an intriguing diagnostic challenge

Multiparametric magnetic resonance imaging (mpMRI) is currently the most effective diagnostic tool for detecting prostate cancer (PCa) and evaluating adenocarcinoma-mimicking lesions of the prostate gland, among which granulomatous prostatitis (GP) represents the most interesting diagnostic challenge. GP consists of a heterogeneous group of chronic inflammatory lesions that can be differentiated into four types: idiopathic, infective, iatrogenic, and associated with systemic granulomatous disease. The incidence of GP is growing due to the increase in endourological surgical interventions and the adoption of intravesical instillation of Bacillus Calmette-Guerin in patients with non-muscle invasive bladder cancer; therefore, the difficulty lies in identifying specific features of GP on mpMRI to avoid the use of transrectal prostate biopsy as much as possible.

Granulomatous prostatitis after bacille Calmette-Guérin instillation resembles prostate carcinoma: A case report and review of the literature

BACKGROUND

Bacille Calmette-Guérin (BCG) instillation is recommended in patients with non-muscle-invasive bladder cancer who have intermediate-risk and high-risk tumors. However, granulomatous prostatitis is a rare complication induced by BCG instillation, which can easily be misdiagnosed as prostate cancer. Here, we report a case of granulomatous prostatitis that resembled prostate cancer.

CASE SUMMARY

A 64-year-old Chinese man with bladder cancer received BCG instillation. Three days later, he stopped BCG instillation and received anti-infective therapy due to the urinary tract infection. Three months after BCG restart, he had rising total prostate-specific antigen (PSA) (9.14 ng/mL) and decreasing free PSA/total PSA (0.09). T2-weighted images of magnetic resonance imaging (MRI) showed a 28 mm × 20 mm diffuse low signal abnormality in the right peripheral zone, which was markedly hyperintense on high b-value diffusion-weighted MRI and hypointense on apparent diffusion coefficient map images. Considering Prostate Imaging Reporting and Data System score of 5 and possibility of prostate cancer, a prostate biopsy was conducted. Histopathology showed typical features of granulomatous prostatitis. The nucleic acid test for tuberculosis was positive. He was finally diagnosed with BCG-induced granulomatous prostatitis. Thereafter, he stopped BCG instillation and received anti-tuberculosis treatment. During 10 mo follow-up, he had no evidence of tumor recurrence or symptoms of tuberculosis.

CONCLUSION

Temporarily elevated PSA and high followed by low signal abnormality on diffusion-weighted MRI are important indicators of BCG-induced granulomatous prostatitis.

Imaging Patterns of Bacillus Calmette-Guérin-Related Granulomatous Prostatitis Based on Multiparametric MRI

Objective

To categorize multiparametric MRI features of Bacillus Calmette–Guérin (BCG)-related granulomatous prostatitis (GP) and discover potential manifestations for its differential diagnosis from prostate cancer

Materials and Methods

The cases of BCG-related GP in 24 male (mean age ± standard deviation, 66.0 ± 9.4 years; range, 50–88 years) pathologically confirmed between January 2011 and April 2019 were retrospectively reviewed. All patients underwent intravesical BCG therapy followed by a MRI scan. Additional follow-up MRI scans, including diffusion-weighted imaging (DWI), were performed in 19 patients. The BCG-related GP cases were categorized into three: A, B, or C. The lesions with diffusion restriction and homogeneous enhancement were classified as type A. The lesions with diffusion restriction and a poorly enhancing component were classified as type B. A low signal intensity on high b-value DWI (b = 1000 s/mm²) was considered characteristic of type C. Two radiologists independently interpreted the MRI scans before making a consensus about the types.

Results

The median lesion size was 22 mm with the interquartile range (IQR) of 18–26 mm as measured using the initial MRI scans. The lesion types were A, B, and C in 7, 15, and 2 patients, respectively. Cohen’s kappa value for the inter-reader agreement for the interpretation of the lesion types was 0.837. On the last follow-up MRI scans of 19 patients, the size decreased (median, 5.8 mm; IQR, 3.4–8.5 mm), and the type changed from A or B to C in 11 patients. The lesions resolved in four patients. In five patients who underwent prostatectomy, caseous necrosis on histopathology matched with the non-enhancing components of type B lesions and the entire type C lesions.

Conclusion

BCG-related GP demonstrated three imaging patterns on multiparametric MRI. Contrast-enhanced T1-weighted imaging and DWI may play a role in its differential diagnosis from prostate cancer.

Differential diagnosis of uncommon prostate diseases: combining mpMRI and clinical information

The differential diagnosis of abnormalities in the prostate is broad, covering common (acinar adenocarcinoma, benign prostatic hyperplasia, chronic prostatitis, hemorrhage, cysts, calcifications, atrophy and fibrosis) and less common conditions (tumors other than acinar adenocarcinoma, granulomatous prostatitis containing tuberculosis, abscesses and other conditions, and idiopathic disorders such as amyloidosis and exophytic benign prostatic hyperplasia). Recent advances in magnetic resonance imaging (MRI) of the prostate gland and imaging guidelines, such as the Prostate Imaging Reporting and Data System version 2.1 (PI-RADS v2.1), have dramatically improved the ability to distinguish common abnormalities, especially the ability to detect clinically significant prostate cancer (csPCa). Overlap can exist in the clinical history and imaging features associated with various common/uncommon prostate abnormalities, and biopsy is often required but is invasive. Prostate abnormalities can be divided into two categories: category 1, diseases for which PI-RADS scores are suitable for use, and category 2, diseases for which PI-RADS scores are unsuitable for use. Radiologists must have an intimate knowledge of other diseases, especially uncommon conditions. Past relevant history, symptoms, age, serum prostate-specific antigen (PSA) levels, MRI manifestations, and the applicability of the PI-RADS assessment should be considered when diagnosing prostate abnormalities.

Male genital tract tuberculosis: A comprehensive review of imaging findings and differential diagnosis

Urogenital tuberculosis is the most common form of extrapulmonary tuberculosis. Genital organ involvement occurs as a continuum of urinary tract tuberculosis and often presents a diagnostic challenge due to the non-specific nature of the symptoms. Delay in diagnosis may lead to complications such as infertility and perineoscrotal sinuses. Imaging plays an important role in raising timely suspicion of tuberculosis. In this article, we describe the imaging findings of male genital tuberculosis and the differential diagnosis. High-resolution ultrasonography (HRUS) is the best modality for assessing the epididymis, testis, scrotum and vas deferens, whereas MRI is optimal for evaluating the prostate, seminal vesicles and ejaculatory ducts. Epididymis is the most common site of genital tuberculosis, and presents as a nodular lesion limited to the tail or as diffuse enlargement. The proximal vas deferens is also frequently involved due to anatomical contiguity and shows diffuse or nodular thickening. Advanced cases may show pyocele formation and scrotal wall sinuses. Testicular involvement is almost always secondary to epididymal tuberculosis and presents as single or multiple nodules, diffuse enlargement, or the 'miliary' pattern. Isolated testicular involvement should raise suspicion of malignancy. Tuberculosis of the prostate is often asymptomatic. The most common imaging manifestations are nodules and the diffuse forms, which may later evolve into abscesses. Fibrosis and calcification occur with healing. Seminal vesicle and ejaculatory duct involvement with fibrosis may cause infertility. Awareness of the imaging findings would enable the radiologist to raise timely suspicion, so that prompt treatment is initiated and complications are prevented.

Prostatitis: imaging appearances and diagnostic considerations

Acute and chronic inflammation of the prostate gland can be attributed to several underlying aetiologies, including but not limited to, bacterial prostatitis, granulomatous prostatitis, and Immunoglobulin G4-related prostatitis. In this review, we provide an overview of the general imaging appearances of the different types of prostatitis, their distinguishing features and characteristic appearances at cross-sectional imaging. Common imaging pitfalls are presented and illustrated with examples.

Comparative prostate MRI before and after chronic granulomatous prostatitis following intravesical bacillus Calmette-Guérin therapy

Background:

Granulomatous prostatitis (GnP) is an interesting complication of bacillus Calmette–Guérin (BCG) therapy as it mimics prostate cancer on clinical, biochemical and imaging examinations. In the era of multiparametric prostate MRI (mpMRI), differentiation of GnP from prostate cancer on imaging is essential.

Case presentation:

We report a case of post-BCG GnP in a patient with nonmuscle invasive bladder cancer, presenting with a prostate-specific antigen level of 21.6 ng/ml and prostate imaging reporting and data system (PI-RADS) 5 peripheral lesions. A mpMRI performed 6 months before showed a score 2 of PI-RADS.

Conclusion:

The comparison of mpMRI images before and after BCG administration gives urologists, oncologists and radiologists a precise idea of the mpMRI changes that occur following BCG administration to eventually prevent unnecessary biopsies in future patients.

Granulomatous prostatitis is a bacillus Calmette–Guérin therapy complication that often mimics prostate cancer. This article gives radiologists, urologists and oncologists a clear multiparametric prostate MRI comparison of the changes that bacillus Calmette–Guérin prostatitis causes on the prostate gland.

Multiparametric MRI appearances of primary granulomatous prostatitis

OBJECTIVE

Radiological features of granulomatous prostatitis (GP) overlap with those of prostate adenocarcinoma. Identification of specific GP features may aid diagnosis. We aimed to evaluate the multiparametric MRI (mpMRI) features of GP.

METHODS

We retrospectively reviewed 16 patients from a cohort undergoing mpMRI and transperineal sector-guided prostate biopsies between July 2012 and May 2017. Images were analysed for lesion location, shape, size, extracapsular extension, signal intensity (SI), apparent diffusion coefficient (ADC) values, dynamic contrast enhancement (DCE) pattern and PI-RADS (Prostate Imaging - Reporting and Data System) v2 score.

RESULTS

Histology revealed 13 cases of nonspecific GP and 3 cases of xanthogranulomatous prostatitis. GP lesions were diffuse involving > 50% of the prostate ( n = 13) or nodular ( n = 3). Signal intensity on T ₂ weighted imaging was low and high on diffusion-weighted imaging. ADC values were low (mean 702 ± 79 × 10^-6 mm/s² ). Five patients had DCE imaging with all cases 'positive' as per PI-RADS scoring, with two cases displaying further ring enhancement consistent with abscess formation. Overall PI-RADS score for all cases was 5, indicating high suspicion of prostate cancer.

CONCLUSION

GP is difficult to differentiate from prostate cancer, but typically gives diffuse changes involving > 50% of the gland on mpMRI, with extracapsular extension and rim-enhancing areas. It should be considered a differential diagnosis in patients with recent urinary tract infection (UTI) or prior Bacillus Calmette-Guerin (BCG) treatment.

ADVANCES IN KNOWLEDGE

Prostate MRI imaging features including diffuse changes, extracapsular extension and rim-enhancing areas, in patients with recent UTI or BCG treatment may help identify granulomatous prostatitis cases.

Natural course of asymptomatic abnormal prostate findings incidentally detected by CT after intravesical BCG therapy

BACKGROUND

Detailed information is not currently available on the incidence, natural course, and management of asymptomatic abnormal prostate findings incidentally detected by radiologic evaluations after BCG therapy for non-muscle-invasive bladder cancer patients.

METHODS

We identified 38 patients who were evaluated by contrast-enhanced CT scans before TUR-BT and after BCG therapy between 2006 and 2012. We evaluated the clinical courses of patients with abnormal radiologic findings of the prostate gland after BCG therapy.

RESULTS

Abnormal findings on CT scans were found in the prostate glands of 11 of the 38 patients examined (28.9%), none of whom exhibited any sign or symptom associated with prostatitis. Abnormal findings included a low attenuation area (n = 6, 15.8%), contrast enhancement (n = 3, 7.9%), and a low attenuation area and contrast enhancement in the prostate gland (n = 2, 5.3%). During the follow-up, abnormal prostate findings disappeared spontaneously in most cases without any anti-bacterial or anti-tuberculous drug treatments. No significant differences were observed in patient clinical backgrounds, with the exception of post-BCG prostate volumes, between patients with and without abnormal CT findings. Furthermore, no significant differences were noted in the incidence of the adverse effects of BCG therapy, tumor recurrence rates, or progression rates between patients with and without abnormal CT findings of the prostate gland after BCG therapy.

CONCLUSIONS

Asymptomatic abnormal prostate findings incidentally detected by CT after BCG therapy are not rare, and these disappear over time during the follow-up period without any treatment.

Multiparametric Magnetic Resonance Imaging Characteristics of Prostate Tuberculosis

Objective

To describe the multiparametric magnetic resonance imaging (MRI) appearance of prostate tuberculosis.

Materials and Methods

Six patients with prostate tuberculosis were analyzed retrospectively. The mean age of the patients was 60.5 years (range, 48-67 years). The mean prostate specific antigen concentration was 6.62 ng/mL (range, 0.54-14.57 ng/mL). All patients underwent a multiparametric MRI examination.

Results

The histopathological results were obtained from biopsies in four men and from transurethral resection of the prostate in two men after the MRI examination. Nodular (33%, 2/6 patients) and diffuse lesions (67%, 4/6 patients) were seen on MRI. The nodular lesions were featured by extremely low signal intensity (similar to that of muscle) on T2-weighted imaging (T2WI). The T2WI signal intensity of the diffuse lesions was low but higher than that of muscle, which showed high signal intensity on diffusion weighted imaging and low signal intensity on an apparent diffusion coefficient map. MR spectroscopic imaging of this type showed a normal-like spectrum. Abscesses were found in one patient with the nodular type and in one with the diffuse type.

Conclusion

The appearance of prostate tuberculosis on MRI can be separated into multiple nodular and diffuse types. Multiparametric MRI may offer useful information for diagnosing prostate tuberculosis.

Multiphase contrast-enhanced magnetic resonance imaging features of Bacillus Calmette-Guérin-induced granulomatous prostatitis in five patients

OBJECTIVE

To evaluate the multiphase contrast-enhanced magnetic resonance (MR) imaging features of Bacillus Calmette-Guérin (BCG)-induced granulomatous prostatitis (GP).

MATERIALS AND METHODS

Magnetic resonance images obtained from five patients with histopathologically proven BCG-induced GP were retrospectively analyzed for tumor location, size, signal intensity on T2-weighted images (T2WI) and diffusion-weighted images (DWI), apparent diffusion coefficient (ADC) value, and appearance on gadolinium-enhanced multiphase images. MR imaging findings were compared with histopathological findings.

RESULTS

Bacillus Calmette-Guérin-induced GP (size range, 9-40 mm; mean, 21.2 mm) were identified in the peripheral zone in all patients. The T2WI showed lower signal intensity compared with the normal peripheral zone. The DWIs demonstrated high signal intensity and low ADC values (range, 0.44-0.68 × 10(-3) mm(2)/sec; mean, 0.56 × 10(-3) mm(2)/sec), which corresponded to GP. Gadolinium-enhanced multiphase MR imaging performed in five patients showed early and prolonged ring enhancement in all cases of GP. Granulomatous tissues with central caseation necrosis were identified histologically, which corresponded to ring enhancement and a central low intensity area on gadolinium-enhanced MR imaging. The findings on T2WI, DWI, and gadolinium-enhanced images became gradually obscured with time.

CONCLUSION

Bacillus Calmette-Guérin-induced GP demonstrates early and prolonged ring enhancement on gadolinium-enhanced MR imaging which might be a key finding to differentiate it from prostate cancer.

Xanthogranulomatous prostatitis: multiparametric MRI appearances

Granulomatous prostatitis is an unusual form of prostatitis, and xanthogranulomatous prostatitis (XGP) is an even rarer granulomatous inflammation. Very few XGP cases have been reported in the literature. The reports concerning MRI features of XGP are even less. The present two cases of XGP in our report have different appearances from previous reports and are accompanied by abscess. We also exhibit the magnetic resonance spectroscopy and dynamic contrast-enhanced MRI characteristics, which have never been reported.

Changes observed in multiparametric prostate magnetic resonance imaging characteristics correlate with histopathological development of chronic granulomatous prostatitis after intravesical Bacillus Calmette-Guerin therapy

Administration of Bacillus Calmette-Guerin (BCG) has been shown to cause granulomatous prostatitis, a rare inflammatory process that can be mistaken for prostate cancer. We present a case of a 78-year-old man on active surveillance for prostate cancer with a subsequent diagnosis of high-grade urothelial carcinoma. After intravesical BCG therapy, he developed chronic granulomatous prostatitis. We present serial magnetic resonance imaging and biopsy data demonstrating the time interval between BCG administration and the manifestation of chronic granulomatous prostatitis.