Paraganglioma of the urinary bladder: can biologic potential be predicted?

Contrast-enhanced CT in the differential diagnosis of bladder cancer and paraganglioma

PURPOSE

We sought to summarize the value of contrast-enhanced computed tomography (CECT) in the differential diagnosis of bladder paraganglioma (BPG) and bladder cancer.

METHODS

The medical records of 19 patients with BPG (13 males, 6 females) and 56 patients with bladder cancer (49 males, 7 females) between November 2007 and June 2023 were retrospectively reviewed. All patients underwent unenhanced and contrast-enhanced CT scanning.

RESULTS

Patient age (46.4 ± 11.1 years vs. 58.6 ± 16.0 years), tumor calcification (1/19 vs. 18/56), stalk (0/19 vs. 10/56), internal vessels (15/19 vs. 19/56) and the enlarged adjacent supplying artery (14/19 vs. 10/56) were significantly different between BPG and bladder cancer (P < 0.05). The CT value in the corticomedullary phase (92.4 ± 16.6 HU vs. 64.0 ± 14.5 HU) and the contrast-enhanced value in the corticomedullary phase (54.5 ± 17.4 HU vs. 28.5 ± 12.8 HU) were significantly greater in BPG patients than in bladder cancer patients (P < 0.001), with corresponding area under the curve values of 0.930 and 0.912, respectively. The optimal cutoff values were 83.2 HU and 38.5 HU, respectively. A CT value > 83.2 HU in the corticomedullary phase and a contrast-enhanced CT value > 38.5 HU in the corticomedullary phase were used to indicate BPG with sensitivities of 78.9% and 89.5%, respectively, and specificities of 94.6% and 75.0%, respectively.

CONCLUSION

The corticomedullary phase of CECT plays an important role in the preoperative differential diagnosis of BPG and bladder cancer.

Genotype-phenotype correlations in paediatric and adolescent phaeochromocytoma and paraganglioma: a cross-sectional study

Phaeochromocytoma (PC) and paraganglioma (PGL) syndromes associated with germline pathogenic variants are associated with high morbidity and mortality. Establishing genotype-phenotype correlations within a young population is challenging due to their rare occurrence.

OBJECTIVE

To describe genotype-phenotype correlations in paediatric and adolescent patients diagnosed with PC/PGL. To establish the incidence of PC/PGL in a young population and prevalence of germline pathogenic variants within this group.

STUDY DESIGN

We conducted a cross-sectional study of patients diagnosed with a PC/PGL aged 0-21 years old who were reviewed within Familial Cancer Services within New South Wales and the Australian Capital Territory, Australia.

RESULTS

A germline pathogenic variant was detected in 80% (24/30) of patients; SDHB: n=12, VHL: n=11, and MAX: n=1. Only patients harbouring a germline pathogenic variant reported a family history of syndromic tumours, those with apparently sporadic disease did not (62.5% versus 0%, p=0.02). All patients with VHL presented with an adrenal tumour compared with 25% of those with SDHB (100% versus 25%, p=0.01). Occurrence of multiple primary PC/PGL was seen in patients with VHL however was absent in patients with SDHB (36% versus 0%, p=0.03). Incidence rate of paediatric PC/PGL was 0.45 cases per million person years.

CONCLUSIONS

PC/PGL diagnosed in children and adolescents were strongly associated with germline pathogenic variants in VHL or SDHB. These patients should be referred to specialist services for family counselling and genetic testing along followed by investigations for the detection of bilateral, multifocal or metastatic disease, and lifelong surveillance for recurrent disease.

The Application and Pitfalls of Immunohistochemical Markers in Challenging Diagnosis of Genitourinary Pathology

CONTEXT.—

The morphologic features of different entities in genitourinary pathology overlap, presenting a diagnostic challenge, especially when diagnostic materials are limited. Immunohistochemical markers are valuable when morphologic features alone are insufficient for definitive diagnosis. The World Health Organization classification of urinary and male genital tumors has been updated for 2022. An updated review of immunohistochemical markers for newly classified genitourinary neoplasms and their differential diagnosis is needed.

OBJECTIVE.—

To review immunohistochemical markers used in the diagnosis of genitourinary lesions in the kidney, bladder, prostate, and testis. We particularly emphasized difficult differential diagnosis and pitfalls in immunohistochemistry application and interpretation. New markers and new entities in the 2022 World Health Organization classifications of genitourinary tumors are reviewed. Recommended staining panels for commonly encountered difficult differential diagnoses and potential pitfalls are discussed.

DATA SOURCES.—

Review of current literature and our own experience.

CONCLUSIONS.—

Immunohistochemistry is a valuable tool in the diagnosis of problematic lesions of the genitourinary tract. However, the immunostains must be carefully interpreted in the context of morphologic findings with a thorough knowledge of pitfalls and limitations.

Metastatic paraganglioma presenting with spinal cord compression requiring urgent surgery

We report a rare case of a functional bladder paraganglioma diagnosed in a young man who presented with acute compressive thoracic myelopathy secondary to vertebral metastasis. A histological diagnosis of a metastatic paraganglioma was made following biopsy of a rib lesion. CT revealed a lesion in the inferior wall of the bladder, which demonstrated avid uptake on 68Ga-DOTATATE PET/CT. Serum metanephrine levels were more than 40 times the upper limit of normal. The patient was hypertensive and treatment with doxazosin was initiated. In view of neurological deterioration, he required urgent spinal decompression to preserve neurological function and prevent permanent paraplegia. Despite inadequate alpha-blockade, surgery was successful, and the perioperative course was uneventful. Alpha-blockade was subsequently optimised. Treatment with cyclophosphamide, vincristine and dacarbazine was started but, in view of disease progression, treatment was subsequently changed to sunitinib.

Imaging of neuroendocrine neoplasms of the male GU tract

Male genitourinary neuroendocrine neoplasms (GU-NENs) are rare, without any definite imaging characteristics. The WHO classified neuroendocrine neoplasms in the 2016 classification of the tumors of the urinary tract and genital organs along with other GU tumors; however, no pathologic grading system is available as published for gastroenteropancreatic neuroendocrine neoplasms. Often a multimodality approach using cross-sectional imaging techniques, such as molecular imaging and histopathology are implemented to arrive at the diagnosis. This article provides a review of the pathology and imaging features of the male GU-NENs.

Paraganglioma (pheochromocytoma) of the urinary bladder: A systematic review with a diagnostic, management and treatment algorithm

Introduction:

Paraganglioma of the urinary bladder is a rare but well-documented tumour. Herein, we provide the largest, comprehensive systematic review of the literature and aim to increase familiarity with this rare but significant neoplasm.

Methods:

A systematic review of the literature was conducted on the NCBI PubMed database. The search criteria were not limited to any specific years or languages. There were 418 articles between January 1953 and August 2020, of which 255 case reports were selected.

Results:

Paragangliomas of the urinary bladder most commonly occurred in Caucasians in the fifth decade of life, most commonly presenting with haematuria and variations of ‘micturition attacks’. Eighty percent of tumours were functionally active. The mucosa was normal in 91% of patients. In all, 25% of tumours were treated with transurethral resection alone, 65% had partial cystectomy and 5% had radical cystectomy. Alpha-blockers were administered pre-operatively in 38% of patients and the risk of intra-operative hypertensive crisis was over three times greater in those who did not receive an alpha-blocker. The tumour was confined to the bladder in 75% of cases. Metastasis occurred in 20% of cases, most commonly to iliac nodes. The mean follow-up time was 26.5 months. In cases that documented follow-up, 18.6% had recurrence, most commonly in lymph nodes and bone.

Conclusion:

All patients presenting with micturition attacks or haematuria with a computed tomography showing an enhancing, well-defined submucosal bladder lesion and/or cystoscopy showing a lesion with normal overlying mucosa should be worked up for a possible paraganglioma of the urinary bladder.

Level of evidence:

Not applicable

Bladder paragangliomas: a pictorial review

Bladder paragangliomas (bPGL) are rare neuroendocrine tumors arising from the sympathetic paraganglia present in the bladder wall. Bladder PGLs are typically submucosal or intramural but when subserosal may not be readily visible at cystoscopy. The average size at presentation is 3.9 cm (range 1.0-9.1 cm). When small, bPGL are usually spherical, well-marginated and homogeneous. Larger bPGL are typically more complex with peri- and intra-tumoral neovascularity and central necrosis. On ultrasound, increased color Doppler signal is typical. The increased soft tissue resolution of MRI enables localization of bPGL within the bladder wall more accurately than CT. Restricted diffusion and avid contrast enhancement help differentiate small bPGLs from leiomyomas, which have similar appearances on ultrasound and CT. Nuclear medicine techniques identify bPGLs and their metastases with high specificity, ⁶⁸Ga-DOTATATE PET/CT having largely replaced ¹²³I-mIBG SPECT/CT as the first line functional investigation. Imaging is essential to aid surgical planning, as endoscopic resection is often not possible or incomplete due to tumor location. For patients with advanced disease, ⁶⁸Ga-DOTATATE PET/CT and ¹²³I-mIBG SPECT/CT assess suitability for peptide receptor radionuclide therapy. Up to 63% of bPGL patients have a germline mutation, most commonly in the SDHB subunit gene, increasing their risk of developing pheochromocytomas and further paragangliomas; lifelong annual biochemical and periodic imaging screening from skull base to pelvis is therefore recommended.

Extra-adrenal paraganglioma of a urinary bladder in an adolescent male: A rare case report

Introduction and importance

Paraganglioma of the urinary bladder is unusual and reported rarely. The patient usually presents with the complaint of hematuria and fluctuating blood pressure.

Case presentation

We discuss the case of a 21-year old male, who had been experiencing gross hematuria, was found to have a mass on ultrasonography. Further evaluation with contrast-enhanced computerized tomography (CECT) revealed an irregular soft tissue density of endophytic mass arising from the left posterior wall of the urinary bladder. The histopathological examination of the excised mass was suggestive of a tumor of neural origin, which was further confirmed as paraganglioma by immunohistochemistry.

Clinical discussion

Imaging prior to the surgery must be done for a provisional diagnosis of paraganglioma to avoid fluctuating blood pressure during elective surgery. On histopathological examination tumor cells are arranged in the nest like fashion forming a specific ‘Zellballen’ pattern. Positive staining for synaptophysin and chromogranin in immunohistochemistry confirms the diagnosis.

Conclusion

It is difficult to diagnose paraganglioma of the urinary bladder with the aid of imaging only, particularly if the patient presents without specific symptoms of fluctuating blood pressure. So, a multidisciplinary approach is essential for the diagnosis and proper therapy of this entity. However, prompt surgical resection is the mainstay of treatment.

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Paraganglioma of the urinary bladder is a rare tumor.

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It is suspected if the patient presents with fluctuating blood pressure during micturition and imaging shows a mass.

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Histopathological examination and immunohistochemical studies of the lesion aid in reaching a definitive diagnosis.

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Surgical resection is the mainstay of treatment.

Micturition-triggered severe headache associated with bladder paraganglioma: A case report

BACKGROUND

Paragangliomas are rare neuroendocrine tumors, especially in the bladder. Although many paragangliomas are non-functional, functioning paragangliomas present with many non-specific signs and symptoms, such as hypertension and headache, complicating their diagnosis. Here, we report a case of micturition-induced severe headache associated with a bladder paraganglioma.Case description: This report describes a severe headache disorder triggered by micturition and associated with a bladder paraganglioma in a middle-aged woman. Her pain occurred consistently after micturition, beginning from the left side of the nose and gradually extended to the forehead and the parietal and occipital regions. The headaches lasted 5-10 min. Removal of the paraganglioma completely eliminated the patient's pain syndrome.

CONCLUSION

This case elucidates the association between micturition-triggered headaches and bladder paragangliomas. The presence of a post-micturition severe headache should suggest the possibility of a bladder paraganglioma.

Bladder paraganglioma: a case report

Bladder Paraganglioma is a rare type of bladder tumor (0.06%). It is typically benign and the most common symptoms are hematuria, hypertension and headache. About 14% of these tumors are malign and consequently radio and chemoresistants. Therefore, surgery is the mainstay of treatment. As they are likely to recur and to metastize lifelong follow-up is required. The authors report a rare case of a 53 years old man with hematuria and a previous history of micturition syncope who was diagnosed with bladder lesion. During the transurethral ressection of bladder he became severely hypertensive. Plasma metanephrines, and urinary vanillylmandelic acid, were still high and the exams suggested residual tumor. The patient underwent radical cistoprostatectomy. After 4 years of follow-up the patient remains disease free.

Bladder Preservation for Patients With Bladder Paragangliomas: Case Series and Review of the Literature

Bladder paragangliomas are rare tumors, with no prospective studies or guidelines on the management of this disease. We present a case series of 6 patients managed with bladder preservation over a median follow-up period of 124 months. We also present a review of the recent literature on bladder paragangliomas. We aim to provide a timely synthesis of the recent evidence on bladder paragangliomas as changing paradigms necessitate individualized treatment.

The applicability and utility of immunohistochemical biomarkers in bladder pathology

Urinary bladder specimens are frequently encountered in the daily practice of surgical pathologists. The spectrum of pathologic entities encountered in bladder specimens is extraordinarily broad, and in some instances, immunohistochemical stains are used to help characterize challenging bladder lesions. Cost-effective biomarker selection tailored to the differential diagnosis facilitates an accurate diagnosis. This comprehensive review is prepared as a reference guide for the use of immunohistochemistry to categorize primary and secondary bladder neoplasms and to evaluate metastatic cancers for possible bladder origin.

Survival After Partial Cystectomy for Variant Histology Bladder Cancer Compared With Urothelial Carcinoma: A Population-based Study

BACKGROUND

The present study tested cancer-specific (CSM) and overall mortality (OM) after partial cystectomy (PC) for variant histology bladder cancer (non-urothelial carcinoma of the urinary bladder UCUB), relative to UCUB and relative to radical cystectomy (RC).

MATERIALS AND METHODS

Within the Surveillance, Epidemiology, and End Results registry (2001-2016), we identified patients with stage T1-T2N0M0 non-UCUB and UCUB who had undergone PC or RC. Non-UCUB included adenocarcinoma, squamous carcinoma, neuroendocrine carcinoma, and other histologic subtypes. First, CSM and OM after PC were compared between the non-UCUB and UCUB groups. Second, CSM and OM after PC were compared with RC in the non-UCUB group. Kaplan Meier plots and multivariable Cox regression models were used before and after inverse probability of treatment weighting.

RESULTS

Overall, 248 patients (16.3%) treated with PC had had non-UCUB. Of the 248 cases, 115 (46.5%), 50 (20%), 34 (14%), and 49 (19.5%) were adenocarcinoma, squamous carcinoma, neuroendocrine carcinoma, and other histologic subtypes, respectively. The comparison between PC in the non-UCUB and PC in the UCUB group showed higher CSM (hazard ratio, 1.4; P = .03) but the same OM rates (hazard ratio, 1.1; P = .7) in the non-UCUB group. The comparison between PC and RC for the non-UCUB group showed no CSM or OM differences.

CONCLUSIONS

PC for non-UCUB was associated with higher CSM compared with PC for UCUB. However, PC instead of RC for select patients with non-UCUB appears not to undermine cancer-control outcomes. Thus, the excess CSM is probably unrelated to cystectomy type but could originate from differences in the tumor biology. These results could act as hypothesis generating for the design of future trials.

Frequency and extent of cytokeratin expression in paraganglioma: an immunohistochemical study of 60 cases from 5 anatomic sites and review of the literature

The absence of cytokeratin expression in paraganglioma helps to differentiate it from other neuroendocrine neoplasms such as carcinoid tumor. Although rare cytokeratin positive paragangliomas have been reported, there are no large systematic studies of this phenomenon. The aim of this study was to determine the frequency and extent of cytokeratin expression in paragangliomas using a large cohort of cases from multiple anatomic sites. Immunohistochemical staining for keratin AE1/AE3 (mouse monoclonal, MAB3412; Millipore) and CAM 5.2 (mouse monoclonal, 349 205; Becton-Dickinson) was performed on whole-tissue sections from 60 resected paragangliomas from the head and neck (36), thorax (10), abdomen (8), intradural/epidural spine (5) and bone, left iliac (1). Cytokeratin expression was identified in only 2/60 (3.3%) cases. One was a mediastinal paraganglioma with moderate to strong expression of keratin AE1/AE3 and CAM 5.2 in <5% tumor cells. The other was a lumbar intradural paraganglioma positive for CAM 5.2 (moderate to strong, 80% of tumor cells) but negative for keratin AE1/AE3. All other paragangliomas (58/60, 96.7%) were negative for keratin AE1/AE3 and CAM 5.2. This study - the largest series of cytokeratin-stained whole-tissue sections of paragangliomas to date - supports the dictum that most paragangliomas are cytokeratin negative. Rare exceptions may be site-related.

Postmicturition syndrome: a neglected syndrome dangerous for the bladder and the heart

Postmicturition syndrome refers to symptoms caused by overdistension of the bladder or micturition. Bladder paraganglioma is a rare neuroendocrine neoplasm, which arises from the chromaffin tissue of the sympathetic nervous system embedded in the muscle layer of the bladder wall. Clinical presentation of catecholamine-secreting paragangliomas may mimic that of hyperfunctioning adrenal pheochromocytoma. Typical symptoms such as sweating, palpitations, headache, nausea, hypertension, or flushing are due to catecholamine release and are related to micturition or bladder overdistension. We herein report the case of a 22-year-old woman admitted to the Emergency Department because of cranial trauma secondary to a car accident. She referred history of micturition-related headache, nausea, sweating, and increase in blood pressure since she was 13 years old. The neurological investigation was normal. No urogenital tract investigation was performed and, on admission, blood pressure was 190/125 mmHg. During hospitalization, abdominal ultrasonography, performed to rule out secondary hypertension, unexpectedly showed a large vascular soft tissue mass in the bladder wall, compatible with a paraganglioma. Twenty-four hours of urinalysis of catecholamines revealed high values of urine metanephrines. Abdominal magnetic resonance imaging and histopathological evaluation of the surgical specimen, following resection of the bladder lesion, confirmed the diagnosis. Our case underlines the importance not to underestimate symptoms compatible with postmicturition syndrome, especially in young patients, to make early diagnosis of bladder paraganglioma.

Genitourinary paraganglioma: Demographic, pathologic, and clinical characteristics in the surveillance, epidemiology, and end results database (2000-2012)

BACKGROUND

Extra-adrenal paragangliomas (PGLs) are infrequent, benign, and neuroendocrine tumors arising from chromaffin cells of the autonomic nervous system. Most PGLs are sporadic, but up to 32% are associated with inherited syndromes such as neurofibromatosis type 1, von Hippel-Lindau disease, and familial PGL. Although most PGLs develop above the umbilicus, they have been reported in the genitourinary (GU) tract. Owing to the paucity of literature on the rates of GU PGL, the objective of our study is to describe the demographic, pathologic, and clinical characteristics of GU PGL, and compare them to non-GU sites of PGL using the surveillance, epidemiology, and end results (SEER) database.

METHODS

The SEER 18 database was used to identify all cases of PGL from 2000 to 2012. Demographic, pathologic, and clinical characteristics were described using chi-square and t-test for categorical and continuous variables, respectively. The Kaplan-Meier method was used to compare overall survival (OS) between GU and non-GU PGL. Statistical significance was defined as P<0.05. All analyses were performed using excel and SAS/Stat version 9.4.

RESULTS

A total of 299 cases of PGL were retrieved from SEER, and 20 (6.7%) of the total PGL arose from the GU tract. The mean age at diagnosis was higher in non-GU than GU PGL (50.4±17.2 vs. 40.8±15.6, P = 0.026). Furthermore, 75% of GU PGLs developed in the bladder, followed by the kidneys/renal pelvis, and spermatic cord (20%). Non-GU PGL developed most frequently within the endocrine system (43%). PGL, overall, was more common in men than in women, and it was more common in whites than all other races. Although 55.5% of GU PGLs were organ confined, only 22.2% of non-GU PGLs were localized at diagnosis. All cases of PGL were treated with surgery. There were 2 cause-specific deaths in the GU PGL groups between 2000 and 2012. The 5-year OS was 93.3% for GU PGL vs. 65.5% in non-GU PGL (P = 0.062).

CONCLUSIONS

GU PGL remains rare with low incidence (6.7% of all PGL cases) in the US population between 2000 and 2012. Bladder PGL represents just 5% of all PGL. Moreover, GU PGL had better OS compared to PGL developing outside of the GU tract although the P-value only approached statistical significance. The bladder represents the most common site of involvement, and surgery is the mainstay of treatment for GU PGL. Clearer prognostic factors, including tumor grade and stage, are needed to better elucidate PGL management in the future; thus, pooled studies from various institutions with detailed clinical information are needed to delineate these prognostic factors.

[Specific types of bladder cancer]

Bladder cancer shows rare variants and special subtypes with diverse prognostic importance and therefore may necessitate different therapeutic approaches. For pathologists it is important to histologically diagnose and specify such variants. Nested variants of urothelial carcinoma with inconspicuous, well-formed tumor cell nests present with an aggressive course. The plasmacytoid variant, which morphologically resembles plasma cells is associated with a shorter survival time and a high frequency of peritoneal metastasis. Micropapillary urothelial carcinoma with small papillary tumor cell islands within artificial tissue retraction spaces and frequent lymphovascular invasion also has a poor prognosis. Other important rare differential variants listed in the World Health Organization (WHO) classification are microcystic, lymphoepithelioma-like, sarcomatoid, giant cell and undifferentiated urothelial carcinomas. Additionally, there are three special types of bladder cancer: squamous cell carcinoma, adenocarcinoma and small cell neuroendocrine carcinoma of the bladder. These tumors are characterized by pure squamous cell or glandular differentiation and are sometimes less responsive to adjuvant (chemo)therapy. Small cell carcinoma of the bladder mimics the neuroendocrine features of its pulmonary counterpart, shows an aggressive course but is sensitive to (neo-)adjuvant chemotherapy. The morphology and histology of the most important variants and special types are discussed in this review.

Urinary Bladder Paragangliomas: Analysis of Succinate Dehydrogenase and Outcome

Paragangliomas of the urinary bladder can arise sporadically or as a part of hereditary syndromes including those with underlying mutations in the succinate dehydrogenase (SDH) genes, which serve as tumor suppressors. SDH deficiency can be screened for by absence of immunohistochemical detection of SDHB. In this study of 11 cases, clinical follow-up was available for 9/11 cases. The cases were reviewed and graded based on the grading system for adrenal pheochromocytomas and paragangliomas (GAPP) criteria. Immunohistochemistry was performed for Ki67 and SDHB. Proliferative index was calculated by quantification of Ki67-positive cells at hot spots. The medical record was accessed for documentation of germline SDH mutations. Urinary bladder paragangliomas had a female predilection (8/11 cases), and 5/11 cases exhibited metastatic behavior. Patients with metastatic disease tended to be younger (mean age 43 vs 49 years), have larger lesions (5.8 vs 1.5 cm), and presented with catecholamine excess (4/4 vs 2/6 patients with non-metastatic lesions). Patients with metastatic disease had a higher mean Ki67 proliferation rate (4.9 vs 1.3 %) and GAPP score (mean of 5.8 vs 3.8) (p = 0.01). IHC for SDHB expression revealed loss of expression in 2/6 cases of non-metastatic paragangliomas compared to 4/5 patients with metastatic paragangliomas. Interestingly, of these four patients, two had a documented mutation of SDHB, one patient had a SDHC mutation, and another patient had a history of familial disease without mutation analysis being performed. Our study, suggests that SDH loss was suggestive of metastatic behavior in addition to younger age at diagnosis, larger tumor size, and higher Ki67 proliferation rate and catecholamine type.

Neuroendocrine Tumors of the Urinary Bladder According to the 2016 World Health Organization Classification: Molecular and Clinical Characteristics

Neuroendocrine neoplasms of the urinary bladder are a rare type of tumor that account for a small percentage of urinary bladder neoplasms. These tumors of the urinary bladder range from well-differentiated neuroendocrine neoplasms (carcinoids) to the more aggressive subtypes such as small cell carcinoma. Despite the rarity of the neuroendocrine tumors of the bladder, there has been substantial investigation into the underlying genomic, molecular, and the cellular alterations within this group of neoplasms. Accordingly, these findings are increasingly incorporated into the understanding of clinical aspects of these neoplasms. In this review, we provide an overview of recent literature related to the 2016 World Health Organization Classification of Neuroendocrine Tumors of the Urinary Bladder. Particular emphasis is placed on molecular alterations and recently described gene expression. The neuroendocrine tumors of the urinary bladder are subdivided into four subtypes. Similar to their pulmonary and other extrapulmonary site counterparts, these have different degrees of neuroendocrine differentiation and morphological features. The clinical aspects of four subtypes of neuroendocrine tumor are discussed with emphasis of the most recent developments in diagnosis, treatment, and prognosis. An understanding of molecular basis of neuroendocrine tumors will provide a base of knowledge for future investigations into this group of unusual bladder neoplasms.

Updates in Benign Lesions of the Genitourinary Tract

The genitourinary tract is a common site for new cancer diagnosis, particularly for men. Therefore, cancer-containing specimens are very common in surgical pathology practice. However, many benign neoplasms and nonneoplastic, reactive, and inflammatory processes in the genitourinary tract may mimic or cause differential diagnostic challenges with malignancies. Emerging clinicopathologic, immunohistochemical, and molecular characteristics have shed light on the pathogenesis and differential diagnosis of these lesions. This review addresses differential diagnostic challenges related to benign genitourinary tract lesions in the kidney, urinary bladder, prostate, and testis, with emphasis on recent advances in knowledge and areas most common in diagnostic practice.

Paraganglioma of Urinary Bladder Presenting as An Early Preeclampsia with Successful Perinatal Outcome After Surgery: A Case Report and Review of Literature

Paraganglioma in urinary bladder associated with pregnancy is extremely rare with a prevalence of less than 1%. We report a case of 25-year-old pregnant female who presented with gross haematuria and clot retention during first trimester. MRI pelvis showed a mass antero- inferior to bladder. Transurethral resection biopsy revealed paraganglioma of the urinary bladder. Her workup showed neither raised plasma free normetanephrine levels. Patient underwent partial cystectomy during second trimester. Postoperatively, she is normotensive with normal serum free normetanephrine levels. At term, she delivered a healthy female child. This case highlights a successful perinatal outcome with timely intervention, adequate preoperative control of hypertension and counselling. We report a case of paraganglioma of urinary bladder presenting as an early preeclampsia with successful perinatal outcome after surgery.

Association of urinary bladder paragangliomas with germline mutations in the SDHB and VHL genes

OBJECTIVE

Our primary goal was to examine the clinical characteristics of a series of patients with urinary bladder paragangliomas (UBPGLs), focusing particularly on their genetic backgrounds.

MATERIALS AND METHODS

We analyzed the medical records of patients who presented to the National Institutes of Health with UBPGL from 2000 to 2013 to determine their clinical characteristics and outcomes, biochemical phenotype, tumor size, and genetic background.

RESULTS

Of the 27 patients with UBPGLs who were identified, 17 (63%) had underlying genetic mutations. Overall, 14 (51.9%) patients had a germline mutation in the succinate dehydrogenase subunit B gene (SDHB), and 3 (11.1%) had mutations in the von Hippel-Lindau gene (VHL). Of the 21 patients who had biochemical data available before their first operation, 19 (90.5%) presented with a noradrenergic biochemical phenotype; 7 (33.3%) patients had tumors that also secreted dopamine. In addition, 1 patient (4.8%) had elevated metanephrine levels, and 2 (9.5%) had normal biochemical data. In total, 13 (48.1%) patients in the series were diagnosed with metastatic disease, at either first presentation or follow-up; 6 of these patients (46.1%) had SDHB mutations.

CONCLUSIONS

UBPGLs typically present with a noradrenergic phenotype and are frequently associated with underlying germline mutations. Patients presenting with these rare neuroendocrine tumors should be screened for these mutations. In addition, patients with UBPGLs should be followed up closely for metastatic development regardless of genetic background, as almost half of the patients in this series presented with metastatic disease and less than half of them had SDHB mutations.

The Application of Immunohistochemical Biomarkers in Urologic Surgical Pathology

Context

Tumors of the genitourinary tract can be diagnostically challenging, particularly in core biopsies and cystoscopic biopsies with limited material. Immunohistochemistry is a valuable tool to use when morphology alone is insufficient for diagnosis.

Objectives

To review tumors and benign lesions of the kidney, urinary bladder, prostate gland, testis, and paratesticular structures with an emphasis on difficult differential diagnoses, as well as staining patterns in normal tissue. Recommended immunohistochemical stain panels are discussed that can assist in the diagnostic workup.

Data Sources

Review of current literature.

Conclusions

Immunohistochemistry is a valuable tool, assisting in the diagnosis of problematic tumors and benign lesions of the genitourinary tract.

Small cell carcinoma of the urinary bladder: a contemporary review with a special focus on bladder-sparing treatments

Small cell carcinoma of the urinary bladder (SCCUB) is a rare and aggressive disease. To date, no standard treatment has been proposed due to the lack of prospective studies resulting from the rarity of this disease. Recently published studies of relatively large patient cohorts, however, have shed some light on the management of SCCUB patients. In this article, the authors review the epidemiology, pathogenesis, diagnosis and treatment (based on disease stage), and they then discuss the optimal therapeutic strategy for SCCUB patients, particularly for those with limited, locoregional disease. The authors conclude that multidisciplinary approaches are needed for the optimal management of this aggressive disease. The authors also discuss bladder-sparing approaches for SCCUB patients, compared to those for conventional bladder urothelial carcinoma patients.

Ganglioneuroma with leiomyomatosis of the urinary bladder: A rare tumour causing frequent micturition and dysuria

We present the case of a 34-year-old female, complaining of frequent micturition and progressive dysuria. By cystoscopy and computerized tomography, we found that she had multiple sub-mucosal protuberant lesions in the entire bladder. After surgical excision, she has thus far showed no further signs of the disease. The postoperative histopathologic examination revealed a ganglioneuroma and leiomyomatosis. Urinary bladder paraganglioma is an unusual tumour; when it is combined with leiomyomatosis, it is extremely rare. We describe the main clinical presentation, diagnostic procedures, and pathologic features. We also review the English literature.

GATA3 expression in paragangliomas: a pitfall potentially leading to misdiagnosis of urothelial carcinoma

GATA3 is a zinc-finger transcription factor, which is expressed in various normal and neoplastic tissues. Amongst tumors, it labels urothelial carcinoma, collecting duct carcinoma of the kidney, breast carcinoma, lymphoma and, uncommonly, endometrial carcinoma. Few studies have investigated its positivity in various neoplasms that may mimic urothelial neoplasms. In this study, we evaluated GATA3 expression in urinary bladder paragangliomas, which may closely mimic urothelial carcinomas. We retrieved 12 cases of paragangliomas from the urinary bladder and 20 cases of paragangliomas from non-urologic sites using the Hopkins Pathology Data Base system. GATA3 was positive in 10 of the 12 (83%) urinary bladder paragangliomas studied on routine slide sections. Most (6/12) of the staining was diffusely strong (3+) staining, whereas the rest (4/12) that were positive showed mixed intensities (strong 3+ to moderate 2+). The 20 paragangliomas from other sites were constructed into tissue microarrays, wherein three cores from each tumor were taken. Fifteen out of 20 (75%) paragangliomas outside of the bladder were positive for GATA3 staining. Moderate (2+) or strong (3+) staining was seen in 13/20 (65%) of extravesical paragangliomas, ranging from 5 to 100% of the cell labeling (mean 59%, median 60%). In the remaining 7/20 (35%) cases, only weak (2/7) or negative (5/7) immunoreactivity for GATA3 was seen. An additional 15 cases of metastatic paraganglioma from various primary sites were retrieved with 12 of 15 (80%) metastatic paragangliomas staining positively for GATA3. Overall, for paragangliomas, regardless of site, 78.7% were positive for GATA3. Recognition of this finding will aid pathologists in preventing a misdiagnosis of a urothelial tumor based on GATA3 expression, which is critical given the differences in treatment, follow-up and prognosis between bladder paragangliomas and urothelial carcinoma.

Urinary bladder malignant paraganglioma with vertebral metastasis: a case report with literature review

Paraganglioma is a rare neuroendocrine neoplasm observed in patients of all ages, with an estimated incidence of 3/1,000,000 population. It has long been recognized that some cases are familial. The majority of these tumors are benign, and the only absolute criterion for malignancy is the presence of metastases at sites where chromaffin tissue is not usually found. Some tumors show gross local invasion and recurrence, which may indeed kill the patient, but this does not necessarily associate with metastatic potential. Here, we report a case of vertebral metastatic paraganglioma that occurred 19 months after the patient had undergone partial cystectomy for urinary bladder paraganglioma. We believe this to be a rarely reported bone metastasis of paraganglioma arising originally within the urinary bladder. In this report, we also provide a summary of the general characteristics of this disease, together with progress in diagnosis, treatment, and prognosis.

Incidental paraganglioma of the urinary bladder in a 66-year-old woman

A 66-year-old female patient was referred to drology department when a bladder mass was incidentally found on a transvaginal ultrasound scan. Cystoscopy revealed a small, smooth mass just above the trigone which appeared to be covered with normal urothelium. The histology from this growth after transurethral resection revealed a paraganglioma of the bladder. We will discuss the management of this case and literature review of this finding in this study.

A clinical review of small-cell carcinoma of the urinary bladder

Small-cell carcinoma of the urinary bladder is a rare and aggressive type of bladder cancer that has a poor prognosis. The incidence has been gradually increasing because of the aging population. Owing to its rarity there are no available treatment guidelines. Several retrospective studies and 1 prospective study have provided some insight into therapy for this disease. A multimodal approach that includes chemotherapy, local radiation therapy, and definitive surgery in resectable cases appears to be an optimal management approach.

[Transurethral enucleation of bladder paraganglioma]

Paraganglioma of the urinary bladder is a rare neoplasm that derives from ganglion cells located in the bladder wall and may morphologically simulate a urothelial carcinoma. The authors present the case of a vesical paraganglioma incidentally detected by ultrasound, and entirely removed by transurethral approach from detrusorial wall. Conventional approaches include surgery (partial cystectomy) or laparoscopic procedures, with inspection by transurethral endoscopy; in this case we wanted to avoid the combined approach considering the lesion diameter and the possibility of an easy removal.

Composite paraganglioma-ganglioneuroma of the urinary bladder: a rare neoplasm causing hemodynamic crisis at tumour resection

A 64-year-old man presented with gross painless hematuria. Cystoscopy revealed a submucosal bladder neck mass covered by normal urothelium. During transurethral resection, the patient developed hemodynamic crisis including sinus bradycardia. Histopathologic examination revealed a primary bladder composite paraganglioma-ganglioneuroma (CPG). The patient underwent partial cystectomy and is symptom-free after one year. Bladder CPGs are extremely rare neoplasms that may result in life-threatening catecholamine secretion, especially during tumour manipulation. These tumours require complete surgical excision and should be included in the differential diagnosis of any solitary bladder mass covered by normal urothelium, especially when there is a history of hypertension or micturition attacks.

Nest-Like Features in Bladder, Simulating the Nested Variant of Urothelial Carcinoma

Nest-like structures are the cardinal lesion of different benign and malignant bladder entities. These entities emphasize the biological relevance of the subtle morphological nest plasticity. The authors present 25 benign and malignant neoplasms, sharing the presence of florid nest-like growth and the scarcity or absence of superficial papillary components. Differential diagnostic clues are discussed.

Bladder paraganglioma in adults: MR appearance in four patients

PURPOSE

To document the magnetic resonance imaging (MRI) characteristics of paraganglioma of the urinary bladder in adults.

MATERIALS AND METHODS

The MRI findings and clinical features of pathologically-proven bladder paraganglioma in four patients (three men, one woman; age range, 39-62 years; mean age, 46.8 years) were reviewed retrospectively. All patients underwent MRI in a 1.5 T instrument. The MRI features of the lesions were analyzed, with emphasis on the size, shape, location, margin, signal intensity, degree of MRI enhancement, and apparent diffusion coefficient (ADC) values.

RESULTS

The bladder paragangliomas were located in the posterior vesicle wall (n=2), in the dome of the bladder wall (n=1), or the inferoanterior wall (n=1). On MR images, the tumors were round (n=1) or oval-shaped (n=3) and all exhibited well-circumscribed margins and broad-based attachment to the bladder wall. On T1-weighted images, the lesions demonstrated homogeneous hyperintensity (n=4) compared to the gluteus maximus muscle; while on T2-weighted images, they showed slight hyperintensity (n=4). On contrast-enhanced MR images, all lesions showed intense enhancement. On diffusion-weighted imaging (DWI), the lesions showed hyperintensity (n=4) and the mean ADC value was 0.973×10(-3) mm2/s.

CONCLUSION

Bladder pheochromocytoma appears as a round or oval-shaped intensely enhancing lesion with T1 hyperintensity; these characteristics may facilitate the preoperative determination.

Non-functional paraganglioma of the urinary bladder: a case report

INTRODUCTION

Paragangliomas that originate from the urinary bladder are extremely rare. In most series, bladder paragangliomas often cause micturitional attacks. Treatment modalities include transurethral resection and cystectomy (partial or total). Prognosis of bladder paraganglioma is similar to that of adrenal pheochromocytoma.

CASE PRESENTATION

A 55-year-old Chinese woman presenting with the sole complaint of lower abdominal pain for one month was admitted to our hospital. Ultrasound and computed tomography revealed a mass on the dome of the bladder measuring 4.0 x 3.0 cm. The tumor was completed removed by laparoscopic partial cystectomy. Histological examination of the tumor indicated paraganglioma of the urinary bladder. The clinical features, diagnosis, management and pathological findings of paraganglioma of the urinary bladder are discussed.

CONCLUSIONS

Bladder paraganglioma should be considered as a differential diagnosis to neoplasm in the urinary bladder, although there is no characteristic symptom. Laparoscopic partial cystectomy may be the first choice in treating paraganglioma of the urinary bladder, offering several advantages such as less invasion, rapid recovery and early discharge from the hospital.

Paratesticular paraganglioma: a rare cause of an intrascrotal mass

We describe a case of a paratesticular paraganglioma in a 33-year-old man who presented with a scrotal mass and underwent a right testicular exploration. Metastasis is the only definite criterion for diagnosis of a malignant paraganglioma; however, lymphovascular invasion was noted in this case, which warranted a close clinical surveillance. The patient is currently well with no evidence of disease 18 months after radical orchiectomy. Paratesticular paragangliomas are extremely rare tumors with 6 cases reported in English literature. The histogenesis of these tumors is unknown. Though the histology and immunohistochemistry resemble those of paragangliomas at any other location, these tumors raise a plethora of differential diagnoses especially with the more commonly occurring tumors. Herein the relevant histopathologic differential diagnoses are discussed along with a brief review of literature.

Urothelial Carcinoma and its Variants

Bladder cancer is the ninth most common cancer worldwide, and the most common malignancy affecting the urinary tract, with approximately 330,000 new cases and more than 130,000 deaths per year. Bladder cancer is primarily attributable to smoking, which accounts for 65% of male and 30% of female cases in some developed countries. Other major risk factors include analgesic abuse, some types of chemotherapy, occupational exposure to chemicals, and in Egypt and some Asian regions, endemic infection with Schistosoma haematobium. Approximately 90% of bladder tumors are classified as urothelial carcinoma (UC), also referred to as transitional cell carcinoma (TCC), and are believed to originate from transformation of the normal urothelium. UCs often exhibit elements of squamous or glandular differentiation. The spectrum of microscopic forms of urothelial carcinoma has been expanded recently to include several histologic variants, the recognition of which is important to avoid diagnostic misinterpretation, to predict outcome, and to guide the selection of the most appropriate therapeutic approach. This article reviews characteristic pathologic features and key clinical aspects of UC and its most common variants.

Urinary bladder paraganglioma in a case of von Hippel-Lindau disease

Pheochromocytoma is a well-known association in patients with von Hippel-Lindau disease. However, extra-adrenal pheochromocytoma or paraganglioma with this association is rare. We describe a patient with von Hippel-Lindau disease who presented with haematuria and was diagnosed to have a urinary bladder paraganglioma, which is an extremely rare tumour. Herein we report this case which, to the best of our knowledge, represents the first case highlighting the association of urinary bladder paraganglioma with von Hippel-Lindau disease.

Small cell carcinoma of the urinary bladder--histogenesis, genetics, diagnosis, biomarkers, treatment, and prognosis

Small cell carcinoma of the urinary bladder is a rare but highly aggressive malignancy with a dismal prognosis. Most patients present with advanced disease at the time of diagnosis. Hematuria is the most frequent presenting symptom. Histologically, small cell carcinoma of the urinary bladder is indistinguishable from its pulmonary counterpart. Coexistence with other types of carcinoma is common. Histogenesis is uncertain; there are several competing theories, including origin from stem cells, from urothelial cells, and from neuroendocrine cells in normal or metaplastic urothelium. The molecular pathogenesis remains unclear. Immunohistochemical staining can be extremely helpful in establishing the diagnosis, and in investigating the use of potential therapeutic strategies. Currently, combinations of surgical resection, chemotherapy, and radiation therapy represent the main treatment options. The recent observation of c-kit and epidermal growth factor receptor expression in more than 25% of patients with urinary bladder small cell carcinoma opens new avenues for further investigation. Improvement in survival may depend upon the identification of new molecular markers to facilitate earlier diagnosis and the development of novel targeted therapies. In this paper, we review general aspects of small cell carcinoma of the urinary bladder, focusing on the ways in which our understanding of this entity has been positively influenced by studies of the histopathologic and immunohistochemical findings, and by investigations of genetic alterations in this disease.

Soft tissue tumors of the urinary bladder, Part I: myofibroblastic proliferations, benign neoplasms, and tumors of uncertain malignant potential

Most bladder tumors arise from the urothelium. However, there are several uncommon but significant bladder lesions that must be differentiated from urothelial carcinomas. These include both benign and malignant spindle cell lesions. The first half of this 2-part review will describe benign myofibroblastic proliferations including inflammatory myofibroblastic tumor and postoperative spindle cell nodule; benign neoplasms including leiomyoma, hemangioma, neurofibroma, and schwannoma; and tumors of uncertain malignant potential including paraganglioma, granular cell tumor, and perivascular epithelioid cell tumor. Common clinical presentations, morphological characteristics, and immunohistochemical features are described to aid the practicing pathologist in the identification of these entities. This review also describes current theories as to the pathogenesis of inflammatory myofibroblastic tumor and postoperative spindle cell nodule and details the current molecular markers identifying several of these lesions.

Neuroendocrine lesions of the genitourinary tract

Neuroendocrine differentiation in tumors of the upper and lower urinary tracts, prostate, and testis is rare. The current review surveys the most significant pathologic and clinical features of primary neuroendocrine lesions at these sites, with emphasis on the cell types from which they derive. As many tumors in this spectrum often bear strong morphologic resemblance to similar neoplasms in other organs, the importance of considering secondary involvement of the genitourinary tract cannot be overstated.

Small-cell carcinoma of the urinary bladder: diagnosis and management

Small-cell carcinoma of the urinary bladder (SCCUB) accounts for less than 1% of all cancers arising in the urinary bladder. Current diagnosis and management of SCCUB are often patterned after small-cell lung cancer (SCLC). However, SCCUB therapy is different from that for SCLC. For example, many patients with SCCUB undergo local resection, which is rarely performed in SCLC. As in SCLC, platinum-etoposide combination chemotherapy is employed as the main systemic treatment option for SCCUB. Chemotherapy is usually combined with other therapeutic modalities, especially in patients whose disease is limited to the locoregional area. Owing to the rarity of this malignancy, no prospective study has been performed that establishes the efficacy and duration of chemotherapy or the relative efficacy of platinum-etoposide versus other chemotherapeutic regimens. This article provides a comprehensive review of the current status of SCCUB diagnosis and management, as well as some unique insights into this rare tumor.

Carcinoid tumors of the urinary tract and prostate

CONTEXT

Carcinoid tumors are exceedingly rare in the genitourinary tract and may occur in the kidney, urinary bladder, urethra, or prostate.

OBJECTIVE

To review the clinical and pathologic features of carcinoid tumors occurring in the urinary tract and prostate.

DATA SOURCES

We searched the English language literature using MEDLINE and Ovid.

CONCLUSIONS

Carcinoid tumors of the urinary tract and prostate share similar morphologic features with their counterparts in other organs. The differential diagnosis includes metastatic carcinoid tumor, paraganglioma, and nested variants of urothelial and prostatic carcinomas. Correlation of the clinical presentation and histopathologic features (including the immunohistochemical profile) will ensure accurate diagnosis of these rare tumors.

Laparoscopic resection of urinary bladder paraganglioma: a case report

The case report of a 55-year-old woman with an incidentally diagnosed urinary paraganglioma of the bladder is presented. The patient had no irritative voiding symptoms, hematuria or hypertension. She was diagnosed to have an immobile solid mass on the left side neighboring the lower segment of the uterus. Transvaginal ultrasonography revealed a well-limited ovoid mass with solid and cystic areas adjacent to the urinary bladder and the uterus. Tumor markers were within normal range. Laparoscopy was performed for the treatment of the mass and complete excision of the cyst was accomplished. Frozen section was performed revealing a benign cystic structure but the identification of the origin was left to definitive histopathological examination which showed paraganglioma of the bladder. Immunohistochemically, the tumor cells were strongly positive for chromogranin A and synaptophysin and there was focal positiveness for neuron specific enolase although vimentin and cytokeratin were negative.