Tumour-like lesions of the urinary bladder

A case report of atypical granular cell tumor of bladder

INTRODUCTION AND IMPORTANCE

The development of granular cell tumor (GCT) in urinary bladder is a very rare disorder.

CASE PRESENTATION

We reported a 50-year-old male, who was referred with vague pelvic pain. There was a hypoechoic mass with diameters of 30*25 mm in frontal wall of bladder in the sonogram.

CLINICAL DISCUSSION

The patient underwent transurethral resection of the bladder tumor. Subsequent pathology and immunohistochemistry findings supported the diagnosis of atypical GCT.

CONCLUSION

The patient was tumor-free at the follow up. It seems that GCT is usually benign in nature and can be treated by excisional surgery.

A Rare Case of Urinary Bladder Hamartoma Clinically Mimicking an Urothelial Carcinoma: A Case Report and Review of the Literature

Urinary bladder hamartoma is a rare benign proliferation with only 14 cases reported in the literature at present. Urinary bladder hamartoma is composed of a disorderly admixture of normal urinary bladder components, essentially represented by glands lined by transitional epithelium and a variable percentage of fibrous stroma, smooth muscle bundles, and adipose tissue. Urinary bladder hamartomas do not exhibit cytological or architectural abnormalities and show no necrosis or increase in mitotic activity. Clinical manifestations are usually represented by lower urinary tract symptoms, more or less frequently paired with gross hematuria. Several pediatric cases of urinary bladder hamartoma have been reported, sometimes with syndromic associations. Transurethral resection has been curative in all cases reported, with no evidence of recurrence. Here we report an additional rare urinary bladder hamartoma, clinically mimicking urothelial carcinoma, providing a review of the literature regarding this unusual entity.

Tumefactive Nonneoplastic Proliferative Pseudotumors of the Kidneys and Urinary Tract: CT and MRI Findings with Histopathologic Correlation

A diverse spectrum of pathologically distinct, nonneoplastic, proliferative conditions of the kidneys and urinary tract demonstrate a expansile growth pattern similar to that of neoplasms. The renal pseudotumors include myriad causes of infections as well as rare noninfectious causes such as sarcoidosis, amyloidosis, and immunoglobulin G4-related disease (IgG4-RD). Rare entities such as cystitis cystica, endometriosis, nephrogenic adenoma, and pseudosarcomatous myofibroblastic proliferation and distinct types of prostatitis comprise tumefactive nontumorous disorders that affect specific segments of the urinary tract. The pseudotumors of the kidneys and urinary tract demonstrate characteristic histopathologic and epidemiologic features, as well as protean clinical manifestations, natural history, and imaging findings. Many patients present with genitourinary tract-specific symptoms or systemic disease. Some cases may be incidentally discovered at imaging. Some entities such as perinephric myxoid pseudotumors, IgG4-RD, fibroepithelial polyp, and nephrogenic adenoma display specific anatomic localization and disease distribution. Imaging features of multisystem disorders such as tuberculosis, sarcoidosis, and IgG4-RD provide supportive evidence that may allow precise diagnosis. Fungal pyelonephritis, xanthogranulomatous pyelonephritis, IgG4-RD, actinomycosis, and endometriosis show markedly low signal intensity on T2-weighted MR images. Although some pseudotumors exhibit characteristic imaging findings that permit correct diagnosis, laboratory correlation and histopathologic confirmation are required for definitive characterization in most cases. A high index of suspicion is a prerequisite for diagnosis. Accurate diagnosis is critical for instituting optimal management while preventing use of inappropriate therapies or interventions. Surveillance CT and MRI are frequently used for monitoring the response of pseudotumors to therapy. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Phyllodes Tumor of the Bladder in a 2-Year-Old Boy - An Exceptional Finding

Background: Breast phyllodes tumor has a distinct histologic appearance. There are no pediatric phyllodes tumors of the bladder in English literature reported. Case report: A 2-year-old boy presented with a urinary infection and obstructive urinary symptoms. A 3-cm slow-growing bladder mass revealed by repeated transabdominal ultrasonography was initially considered a ureterocele. Cystoscopic and laparoscopic exploration using pneumovesicum confirmed the diagnosis of a bladder neck tumor. Histologically, the features were of a benign phyllodes tumor, morphologically similar to those seen in breast tissue. The patient received no further treatment and showed no recurrence or metastasis. Conclusion: Phyllodes tumor can cause a pediatric bladder tumor.

Nephrogenic Adenoma of the Prostatic Urethra Mimicking Prostatic and Bladder Carcinomas

A nephrogenic adenoma is a benign lesion consisting of the proliferation of tubules and glands in the urinary tract. The lesion, thought to be originated from renal tubules, is commonly seen in the urinary bladder. Microscopically, nephrogenic adenoma is composed of a proliferation of small tubules and microcysts encircled by a narrow rim of basement membrane-like hyaline material. There are tubules and microcysts lined by atrophic to undulating hobnail-appearing epithelial cells with bland nuclei and pale eosinophilic to clear cytoplasm. Focal cellular atypia characterized by somewhat coarse chromatin and prominent nucleoli may be present. The stroma is edematous and reveals a granulation tissue-like appearance. By immunohistochemical staining, nephrogenic adenoma is positive for PAX-2, PAX-8, P504S (α-methylacyl-CoA racemase), pan cytokeratin AE1/AE3, CK7, CAM5.2, epithelial membrane antigen (EMA), CD10, and napsin A. Occasionally the lesions are incidentally encountered in the prostatic urethra, which may lead to a misdiagnosis as prostatic adenocarcinoma, clear cell adenocarcinoma or urothelial carcinoma of the urinary bladder. Herein we present a case of nephrogenic adenoma which has been incidentally found in a transurethral resection of a prostate specimen for the management of benign prostatic hypertrophy. The evaluation of morphology, immunohistochemistry, and differential diagnoses have also been discussed.

SATB2 as a Marker of the Proximal Nephron: Expression in Nephrogenic Adenoma and Correlation With Other Renal Tubular Markers

Nephrogenic adenoma (NA) is an infrequent reactive urothelial lesion. The expression of immunohistochemical renal tubular markers has been reported in NA, although a proximal or distal nephron phenotype has not been established. Special AT-rich sequence-binding protein 2 (SATB2) is a marker of a colorectal origin of adenocarcinomas, occasionally reported in renal samples. We have analyzed SATB2 expression in NA, with correlation with other tubular markers, as well as in the normal kidney. Fifty cases of NA were immunostained with PAX8, SATB2, proximal nephron markers [CD10, renal cell carcinoma (RCC) marker, alpha-methylacyl-CoA racemase (AMACR), and CD15], and distal markers (Ksp cadherin, cytokeratin 7, E-cadherin (E-cad), and cytokeratin 19). Ten normal kidney sections were stained with a double method combining SATB2 plus CD10, RCC marker, AMACR, Ksp cadherin, cytokeratin 7, or E-cad. All NA were immunoreactive for PAX8 and 57% for SATB2. Every case was positive for proximal and distal nephron markers: 100% for cytokeratins 7 and 19, 84.1% E-cad +, 81.6% AMACR +, 68.9% Ksp cadherin +, 63% CD15 +, 53.3% CD10 +, and 28.6 % RCC +. In the normal kidney, SATB2 was detected in the straight part of the proximal tubules and the thin descending loops of Henle. NA shows a multiphenotypic pattern with coexpression of both proximal and distal nephron markers, and constant expression of PAX8, cytokeratins 7 and 19. SATB2 is often positive in NA, which should be kept in mind to avoid a possible misdiagnosis of intestinal adenocarcinoma. SATB2 is a marker of the normal proximal nephron.

Molecular genetic and clinical characteristic analysis of primary signet ring cell carcinoma of urinary bladder identified by a novel OR2L5 mutation

To get a better understanding of the genetic basis of primary signet ring cell carcinoma (SRCC) of the bladder, which is highly rare and not yet explored. First, by using immunohistochemistry to find histological pathological characteristics. Second, a massively parallel whole-exome sequencing (WES) was performed on a 58-year-old male patient who had painless macroscopic hematuria and was pathologically diagnosed with primary SRCC of the bladder, followed by comparing with genes of ordinary urothelial cancer (UC) from TCGA. Furthermore, a population-based analysis using the SEER database was performed to investigate the prognosis (SRCC vs. UC). We identified 63 copy number variations (CNVs) with gain counts and 181 CNVs with loss counts. Totally 4515 mutations were discovered in C > T with a success rate of greater than 89%. The most frequently mutated pathway was RTK-RAS which has 85 genes involved in carcinogenic signaling. Final screening on predisposing genes is performed after filtering based on ACMG. Moreover, several driver genes, including NBN, KCTD18, SPATA13, ANKRD36, OR2L5, MALRD1, and LSMEM1, were detected. Sanger sequencing of germline DNA revealed the presence of a mutant base A/G of OR2L5 in the sequence, which was discovered for the first time in primary SRCC of the bladder. Furthermore, the immunohistochemical profile showed that primary SRCC of the bladder were positive for CK7, CK20, GATA-3, and expression of CK(AE1/AE2), EMA, and Ki67. In the SEER-based study, the patients with primary SRCC of the bladder got a worse prognosis compared to those with UC with median months overall survival (OS) 14 vs. 41, respectively, P = 0001, even after adjusting the variables in the Cox regression model, the SRCC of the bladder showed worse survival HR = 1.119, 95% CI = (1.081-1.328), P = 0.0001. These results imply that suppression of potential driver mutations may be a viable adjuvant treatment approach for primary SRCC in the bladder in place of standard chemotherapy, a possibility that warrants further clinical investigation.

Ureteral morphology and pathology during urolithiasis in cats

Cats exhibit high susceptibility to urinary organ-related diseases. We investigated the healthy ureter morphologies and compared these with ureters that were surgically resected distal to a urolithiasis obstruction in cats. Healthy ureters (total length 9.88 ± 0.38 cm) developed adventitia composed of collagen fibers (ADCF), containing a longitudinal muscular layer, toward the distal segment. The healthy ureter was the smallest in the middle segment (4.71-6.90 cm from the urinary bladder) with significantly decreased luminal and submucosal areas compared to those in the proximal segment. Diseased cats exhibited a high incidence of calcium oxalate urolithiasis with renal dysfunction, regardless of age, sex, and body size. Diseased ureters showed increased perimeters, inflammation, and decreased nerves in ADCF. Collagen fibers were increased in the submucosal area, intermuscular spaces, and ADCF, particularly near the obstructed lesion. The mean resected ureter length was 5.66 ± 0.49 cm, suggesting a high obstruction risk in the middle segment. The middle segment also increased the cross-sectional area of the ureter and ADCF, regardless of the distance from the obstructed lesion. The ureters in several cases either lacked the transitional epithelium, or exhibited transitional epithelial hyperplasia, and some of these formed the mucosal folds. In conclusion, we demonstrated the following characteristics and histopathological features of cat ureters: decreases in the ureter size, lumen area, and submucosa area from proximal to middle segment in healthy; ADCF changes in urolithiasis, including increased connective tissues with inflammation and decreased nerves. These data are important to understand the pathogenesis of feline ureteral obstruction.