Primary primitive neuroectodermal tumour of the urinary bladder: a clinico-pathological study emphasising immunohistochemical, ultrastructural and molecular analyses

Single-cell RNA sequencing and spatial transcriptomics of bladder Ewing sarcoma

Bladder Ewing sarcoma/primitive neuroectodermal tumor (bladder ES/PNET) is a rare and highly malignant tumor associated with a poor prognosis, yet its underlying mechanisms remain poorly understood. Here, we employed a combination of single-cell RNA sequencing (scRNA-seq), spatial transcriptomics (ST), and functional analyses to delve into the pathogenesis of bladder ES/PNET. The investigation revealed the presence of specialized types of epithelial cells (referred to as bladder ES-Epi) and mast cells (referred to as bladder ES-Mast) within bladder ES/PNET in comparison to urothelial carcinoma. Notably, TNFRSF12A exhibited significant upregulation in bladder ES/PNET. Furthermore, mast cells possessed the ability to activate epithelial cells through the TNFSF12-TNFRSF12A ligand-receptor signaling pattern. In addition, Enavatuzumab can significantly inhibit the migratory ability of the Ewing sarcoma cell line RD-ES. This groundbreaking study provides unprecedented mechanistic insights into the progression of bladder ES/PNET and introduces a potential therapeutic avenue for treating this challenging malignancy.

Primary primitive neuroectodermal tumor of urinary bladder: a case report and literature review

Primary primitive neuroectodermal tumor (PNET) of the bladder is an extremely rare and highly aggressive neoplasm. We report a case of PNET of the urinary bladder associated with increased serum neuron-specific enolase (NSE) in the presence of relapse and metastasis. A 66-year-old male presented to our department due to painless gross hematuria. Computed tomographic urography (CTU) showed an intraluminal tumor in the anterior bladder wall. Biopsy revealed a malignant small round blue cell tumor. The patient denied radical cystectomy, and partial cystectomy was given together with resection of adjacent peritoneum. The patient was diagnosed with primary bladder PNET after pathological inspection with negative surgical margins. Additionally, he received 6 cycles of chemotherapy using etoposide and cisplatin (EP) regime, and showed recurrence and metastasis afterwards. Disease progression was seen after transurethral resection (TUR) of bladder tumor and radiotherapy. Pelvic and retroperitoneal metastasis triggered bilateral hydronephrosis, and then palliative treatment was given with bilateral percutaneous nephrostomy. Finally, he died 12 months after diagnosis. PNETs are highly aggressive tumors characterized by the expression of MIC2 and neural markers and the presence of EWS-FLI1 translocation. We recommend histologic, immunohistochemical, and cytogenetic analysis in all patients with small round blue cell bladder malignancy in order to rule out other small cell malignancies. Multimodal treatment, including surgery and adjuvant chemotherapy must be initiated. Patients aged ≤30 years underwent complete resection of tumor and standard chemotherapy showed a better prognosis, while those with metastasis, incomplete resection and inadequate response to chemotherapy showed poor prognosis. Moreover, an elevated NSE may indicate a poor prognosis.

Primitive neuroectodermal tumor of the penile urethra

Primitive neuroectodermal tumor (PNET)/Ewing's sarcoma tumors are a group of highly malignant tumors composed of small, round cells showing neuroectodermal differentiation that commonly affects soft tissue and bone. PNET involving the genitourinary system is rare and PNET of the penile urethra is rarer still. It exhibits a highly aggressive biological behavior with poor prognosis. We report a case of a 27-year-old male presenting with penile swelling and difficulty in passing urine. Examination revealed a firm penile urethral mass. Pathological and immunohistochemical results of the specimen obtained from urethroscopic biopsy followed by total penectomy confirmed the diagnosis of PNET of the urethra. He received combination chemotherapy: ifosfamide and etoposide (IE) + vincristine, Adriamycin, and cyclophosphamide (VAC). In conclusion, PNET has to be considered in the differential diagnosis of a penile urethral mass in young patients.

Primitive neuroectodermal tumor of urinary bladder: A case report and literature review

RATIONALE

Primitive neuroectodermal tumor (PNET) of the urinary bladder is a highly aggressive tumor with high local recurrence and distant metastasis rates in cases of incomplete excision. We report a case of a young female patient, in whom early laparoscopic radical cystectomy combined with standard lymph node dissection and a modified vincristine, doxorubicin hydrochloride, and cyclophosphamide (VAC) chemotherapy regimen was controversial. Because PNET of the urinary bladder is a rare malignancy, the standard treatment regimen has not yet been established. It is not clear whether surgery combined with postoperative chemotherapy for PNET patients may be superior to surgery alone on long term survival.

PATIENT CONCERNS

The patient was a 45-year-old Chinese woman who complained of lower urinary tract symptoms, including urgency, frequency, and difficulty in urination, for 2 months.

DIAGNOSES

PNET.

INTERVENTIONS

The patient underwent laparoscopic radical cystectomy and standard lymph node dissection, combined with modified VAC chemotherapy regimens.

OUTCOMES

After undergoing radical surgery in 2018, the patient completed 6 courses of adjuvant chemotherapy. Abdominal and thorax computed tomography scanning was performed 3, 6, 9, and 12 months after the surgery was completely free of tumor. The patient is still alive with no signs of recurrent disease 2 years after diagnosis.

LESSONS

Radical surgery and standard lymphadenectomy combined with adjuvant chemotherapy may be essential to improve the prognosis of PNET of the urinary bladder.

First report of a primitive neuroectodermal tumor of the bladder in a newborn

Primitive neuroectodermal tumor (PNET) is part of the Ewing sarcoma family of tumors. The present case reports a primitive neuroectodermal tumor (PNET) of rare location in the bladder in a newborn. It was evaluated with prenatal ultrasound and postnatal tomography that revealed a mass in the posterior wall of the bladder.

The patient underwent partial cystectomy with subsequent analysis of the surgical piece removed, the histopathological study indicated a tumor of mesenchymal origin, and immunohistochemical staining confirmed the diagnosis of PNET of the bladder. Satisfactory result and short-term follow-up.

Primary adult primitive neuroectodermal tumor of the bladder: A case report and literature review

RATIONALE

A primary primitive neuroectodermal tumor (PNET) is a rare and highly malignant tumor that often occurs in the central nervous system of children and young adults. This tumor is rarely observed in the bladder.

PATIENT CONCERNS

In this paper, we describe the case of a 64-year-old man with a PNET of the bladder. He experienced dull pain in the lower left abdomen for 5 months (without any obvious inducement), which gradually became aggravated and intolerable.

DIAGNOSES

Partial cystectomy was performed, and a PNET of the bladder, which is extremely rare, was confirmed.

INTERVENTIONS

Following cystectomy, the patient's general postoperative state was poor and he could not tolerate chemotherapy. Thus, he was subjected to pelvic radiotherapy for 2 weeks.

OUTCOMES

His physical condition did not improve significantly after radiotherapy; however, we still plan to continue it. If the patient's physical condition improves, chemotherapy will be considered.

LESSONS

Most cases of PNETs are intravesical or at least mainly endophytic. However, in this case, the mucosal layer was barely involved, and the tumor mainly grew out of the bladder, which is very rare. The present case provides reference for the diagnosis of PNET.

Primary round cell sarcomas of the urinary bladder with EWSR1 rearrangement: a multi-institutional study of thirteen cases with a review of the literature

Primary Ewing sarcoma (ES) of the urinary bladder is a rare and aggressive small blue round cell malignant neoplasm associated primarily with translocation involving EWSR1 and FLI1 genes located in the 22nd and 11th chromosomes, respectively. To date, 18 cases have been published in the literature as single-case reports, based chiefly on CD99 positivity (17 patients). Molecular confirmation by fluorescence in situ hybridization was performed in 9 patients, and FLI1 immunohistochemical (IHC) analysis was not performed in any of these published cases. Herein, we present thirteen patients of more comprehensive primary round cell sarcomas of the urinary bladder with EWSR1 rearrangement. Clinicopathologic parameters including demographics; clinical presentation; histopathologic, IHC, and molecular profiles; and management and follow-up data of 13 patients with primary round cell sarcomas with EWSR1 rearrangement (Ewing family of tumor) of the urinary bladder were analyzed. The studied patients (n = 13) included 6 females and 7 males; their age ranged from 4 years to 81 years (median = 30 years). The most common clinical presentation was hematuria (n = 7), followed by hydronephrosis (n = 2, one with renal failure). The tumor size ranged from 2.9 cm to 15 cm in maximum dimension. Conventional ES architecture and histology was observed in 6 cases, and diverse histology was observed in 7 cases (adamantinomatous pattern [n = 1], alveolar pattern [n = 1], ganglioneuroblastoma-like pattern [n = 2], and small cell carcinoma-like pattern [n = 3]). All the tumors were muscle invasive (invasion into the muscularis propria). IHC analysis showed that all tumors expressed FLI1, CD99, and at least one neuroendocrine marker. Focal cytokeratin staining was positive in 2 patients, and RB1 was retained in all patients. EWSR1 rearrangement was seen in 12 of 12 tumors (in 12 patients) tested. A combined multimodal approach that included surgery with chemotherapy was instituted in all patients. Follow-up was available for 11 patients (ranging from 5 to 24 months). Six patients either died of disease (n = 3) or other causes (n = 3). Five patients were alive with metastases to the liver (n = 1), liver and lung (n = 2), liver and abdominal wall (n = 1), and kidney (n = 1). Based on our experience with the largest series to date and aggregate of the published data, ES/round cell sarcomas with EWSR1 rearrangement occurring in the bladder have bimodal age distribution with poor prognosis despite aggressive therapy. Owing to its rarity and age distribution, the differential diagnosis is wide and requires a systematic approach for ruling out key age-dependent differential diagnoses aided with molecular confirmation.

An unusual natural history of a rare bladder tumor: Primitive neuroectodermal tumor

A primary primitive neuroectodermal tumor (PNET) of the urinary bladder is a very rare bladder tumor. There are few described cases in the literature to date. We presented a 70-year-old man with primary nonmetastatic bladder PNET. The diagnosis was confirmed according to immunohistochemistry evaluation. The patient underwent bladder-sparing protocol using radiotherapy and standard systemic multidrug chemotherapy (vincristine + doxorubicin + cyclophosphamide). At the end of three years of follow-up, we performed radical cystoprostatectomy due to newly diagnosed high-grade transitional cell carcinoma of the bladder at the site far from the primary bladder PNET. In conclusion, multimodal bladder sparing protocol including radiotherapy and standard systemic chemotherapy can be used for the management of primary bladder PNET with acceptable oncological outcomes.

Complete resection of a primitive neuroectodermal tumour arising in the bladder of a 31-year-old female after neoadjuvant chemotherapy

Primitive neuroectodermal tumours (PNET) that arise in the urinary bladder are an extremely rare occurrence. Very few cases have been reported so far in the literature1-13 and we report another case here in a 31-year-old-female. The patient presented with polyuria, gross hematuria, followed by development of anuria, and was discovered to have a 9.4 cm mass arising in the posterolateral aspect of the bladder. Histologically, the tumour showed small, round, blue cells. Further analysis using break-apart fluorescent in situ hybridization (FISH) revealed non-random chromosomal translocations of the ews gene suggestive of Ewing sarcoma (ES)/PNET. The patient completed seven cycles of neoadjuvant chemotherapy, which significantly reduced the size of the lesion. Due to the location of the lesion, surgical resection of the entire bladder and urethra with use of a continent cutaneous reservoir was performed. Here, the management of a 31-year-old female with ES/PNET arising from the bladder is reported.

Successful complete resection of Ewing sarcoma arising from the bladder in a 10-year-old boy after chemotherapy

Ewing sarcoma (ES) of the bladder is extremely rare. Here we report the successful treatment of the youngest case of ES arising from bladder encountered to date and a literature review. A 10-year-old boy who presented with polyuria and lower abdominal swelling was found to have a 13 cm mass arising from the bladder localized to the center of the lower abdomen. Biopsy confirmed ES. Following chemotherapy, the mass shrank to 5 cm and was found to be localized to the right side of the bladder with invasion of the right vas deferens. One-third of the right side of the bladder and part of the right vas deferens were resected. No viable cancer cells were detected in the resected specimen, and the surgical margins were reported to be negative. The patient is currently well with no recurrence or metastases after 11 months. There are 12 cases of Ewings sarcoma arising from the bladder reported in the English literature; two cases in children. Our case will be the third pediatric case and the youngest.

Primitive neuroectodermal tumor/Ewing's sarcoma of the urinary bladder: a case report and its molecular diagnosis

We report a rare case of primitive neuroectodermal tumor/Ewing's sarcoma (PNET/ES) arising from the urinary bladder. A 65-year-old man presented with hematuria and dysuria. Computed tomography revealed an enlarged invasive tumor at the base of the bladder. No additional abnormal findings were disclosed by other diagnostic imaging methods. The surgical specimens showed small round cell tumor with positive staining for MIC2 gene product (CD99). EWS-FLI1 fusion transcripts were detected by reverse transcriptase polymerase chain reaction and direct sequencing, confirming the diagnosis of PNET/ES. The patient developed swollen pelvic lymph nodes as well as multiple lung metastases at 8 months postoperatively. No effective results could be obtained even with systemic chemotherapy consisting of vincristine, ifosfamide, doxorubicin and etoposide (VIDE) based on the EUROpean Ewing tumour Working Initiative of National Groups 1999 (EURO-E.W.I.N.G. 99) multinational trial. The patient died of acute superior mesenteric artery thrombosis at 22 months postoperatively. PNET/ES could have been included in past cases of small cell carcinoma because of the difficulty in its differential diagnosis. Exact diagnosis is crucial for deciding the treatment strategy for rare bladder tumors consisting of small round cells.

Primary primitive neuroectodermal tumor of the urinary bladder: a case report and literature review

Primitive neuroectodermal tumor (PNET) arising in the urinary bladder is extremely rare. Here, we report a case of primary PNET of the urinary bladder in an aged Asian man that showed an aggressive clinical course. A 74-year-old man presented with frequency, dysuria, and gross hematuria. Pelvic computed tomography showed a mass in the urinary bladder. Microscopically, the tumor revealed sheets of uniform, small, round, blue cells, and immunohistochemical examination demonstrated primary PNET of the urinary bladder. Palliative chemotherapy was administered. After three courses of chemotherapy, his disease progressed and he died 4 months after diagnosis.

Peripheral primitive neuroectodermal tumor of the urinary bladder in an Arab woman with history of squamous cell carcinoma: a case report

Introduction

Peripheral primitive neuroectodermal tumors of the urinary bladder are rare and tend to occur in an older age group than do their counterparts in bones and soft tissue.

Case presentation

We report a case of peripheral primitive neuroectodermal tumor of the urinary bladder in a 67-year-old woman of Arab origin. She had undergone transurethral resection followed by chemotherapy because of pulmonary metastasized muscle-invasive squamous cell carcinoma of the bladder in 2005. One year later, she first presented with a history of repeated hematuria in our institution. Performing cystoscopy any tumor could be detected. Control cystoscopy two months later showed a tumor mass of 3 cm in diameter at another location than described for the first tumor. After perforating by transurethral resection partial bladder resection had to be done. Tissue specimen after pathological analysis revealed a peripheral primitive neuroectodermal tumor with tumor cells reactive to cluster of differentiation 99, neuron-specific enolase and S100 protein and stained negative for other markers such as cytokeratins, epithelial membrane antigen, desmin, smooth muscle actin, chromogranin and leucocyte common antigen. Staging computerized tomography was especially free from any hint on organ metastasis, but the patient died due to a cardiac problem only a few months later.

Conclusions

To the best of our knowledge, we report the eighth case of bladder peripheral primitive neuroectodermal tumors in literature and the first concerning an Arab patient. It is also the first presentation of a peripheral primitive neuroectodermal tumor patient with a history of squamous cell carcinoma of the bladder. As in other cases, expression of single-chain-type 1 glycoprotein and neural markers was positive and the disease was at an advanced stage at the time of diagnosis.

Divergent differentiation in urothelial carcinoma and other bladder cancer subtypes with selected mimics

Conventional urothelial carcinoma accounts for most carcinomas of the urinary tract lining. However, neoplastic urothelium has the capacity to demonstrate enormous plasticity. A variety of unusual architectural patterns of urothelial carcinoma, such as the nested, microcystic and inverted variants, can be mistaken for reactive processes or benign tumours. Others such as the micropapillary, plasmacytoid and discohesive variants, can mimic metastatic tumour from other sites. The micropapillary variant in particular is more aggressive. In addition, urothelial carcinoma has a propensity to demonstrate divergent differentiation with glandular, squamous, small cell neuroendocrine, lymphoepithelioma-like, sarcomatoid or other elements. Pure squamous carcinoma or adenocarcinoma (the latter in particular) can be difficult to distinguish from contiguous or metastatic spread. Some variants have prognostic and potential therapeutic implications. Molecular genetic evidence has emerged recently supporting a close relationship between urothelial carcinoma and various divergent elements. Sarcomatoid carcinoma and its differential diagnosis with other spindle cell lesions of urinary tract will be covered in a separate review.

A case of a ewing sarcoma family tumor in the urinary bladder after treatment for acute lymphoblastic leukemia

We report the first case of a tumor of the Ewing sarcoma family of tumors arising from the urinary bladder 3 years after chemotherapy for acute lymphoblastic leukemia. A 16-year-old boy complained of macrohematuria and dysuria during the posttreatment follow up of his acute lymphoblastic leukemia. Ultrasonography and computed tomography revealed a 1-cm sized intravesical tumor. The tumor was transurethrally resected with no residual tumor at the margin. Histopathologic analyses revealed a small round blue cell tumor with positive staining for CD99 antibody. EWS-FLI1 fusion transcripts were detected in the tumor tissue by reverse transcriptase polymerase chain reaction. These findings support the diagnosis of Ewing sarcoma family of tumor. After adjuvant multidrug chemotherapy, the patient has shown no evidence of disease for more than 2 years.

Soft tissue tumors of the urinary bladder Part II: malignant neoplasms

Most bladder tumors arise from the urothelium. However, there are several uncommon but significant malignant bladder lesions that must be differentiated from urothelial carcinomas and from benign lesions of the bladder. The second half of this two-part review will describe rare nonurothelial malignant tumors of the urinary bladder including leiomyosarcoma, rhabdomyosarcoma, angiosarcoma, malignant fibrous histiocytoma (undifferentiated sarcoma), primitive neuroectodermal tumor, malignant peripheral nerve sheath tumor, hemangiopericytoma, and alveolar soft-parts sarcoma. Common clinical presentations, morphologic characteristics, and immunohistochemical features are described to aid the practicing pathologist in the identification of these entities. Because the distinction between malignant and benign lesions has significant therapeutic and prognostic implications, key factors for differentiating them are presented.