Pseudosarcomatous and sarcomatous proliferations of the bladder

Pseudosarcomatous Fibromyxoid Tumor of the Prostate: A Rare Benign Lesion Mimicking Malignancy

Psuedosarcomatous fibromyxoid tumor (PSFT) is an uncommon, non-malignant yet locally aggressive pseudotumor found in the genitourinary system. Despite being a benign spindle cell tumor without any documented cases of metastasis, its local aggressiveness can pose a life-threatening risk. The lack of specific clinical symptoms and the infiltrative characteristics of the lesion may lead to misdiagnosis as sarcomatoid carcinoma or sarcoma. Therefore, it is crucial to distinguish PSFT histologically and through immunohistochemistry from other spindle cell tumors to avoid unnecessary investigations and treatments. This case emphasizes the difficulties in diagnosing this uncommon benign tumor because of its infrequent occurrence, limited literature, vague symptoms, and similarities in imaging results with inflammatory or infectious conditions, as well as sarcomatous neoplasms. Precise diagnosis plays a vital role in preventing unnecessary or insufficient treatment.

USP6-associated neoplasm as a tentative subset of postoperative spindle cell nodule

AIM

Postoperative spindle cell nodule (PSCN) is a pseudosarcomatous proliferative lesion of unclear molecular genetic origins.

METHODS AND RESULTS

We examined seven patients with PSCN, using routine haematoxylin-eosin (H&E) slide preparations and a series of immunostains. The latter targeted keratin, vimentin, α-smooth muscle actin (SMA), anaplastic lymphoma kinase (ALK [D5F3]), and other proteins. Ubiquitin-specific peptidase 6 (USP6) and anaplastic lymphoma kinase (ALK) gene rearrangements were also analysed by fluorescence in situ hybridization (FISH). There were histories of prior surgical intervention (n = 6) or trauma (n = 1) in all seven patients. All lesions were highly cellular and mitotically active spindle cell proliferations, with no cytologic atypia, nuclear pleomorphism, or aberrant mitoses. Immunohistochemical (IHC) staining disclosed focal, weak keratin positivity in two lesions, whereas vimentin (diffuse, strongly positive) and SMA (tram-track pattern) were present in each instance, and ALK (D5F3) was entirely negative. FISH analysis confirmed USP6 gene rearrangements in all seven cases, showing no ALK gene rearrangements. RNA sequencing results showed an MYH9::USP6 gene fusion in only one lesion (No. 6).

CONCLUSION

A subset of PSCN is marked by USP6 gene rearrangements, a genetic feature of nodular fasciitis (NF). Given its similarity to NF, a designation as USP6-associated neoplasm (UAN) seems reasonable, signifying a transient clonal neoplastic lesion.

Prognostic value of the sarcomatoid component in bladder cancer: A propensity score matching study

Sarcomatoid carcinoma of the bladder is rare, and little is known about the prognostic impact of the proportion of sarcomatoid components of the bladder. The present study aimed to assess the prognostic value of the proportion of sarcomatoid components with regard to death and recurrence rates in patients with bladder cancer (BC), and to validate the worse survival results of sarcomatoid carcinomas of the bladder using propensity score matching. Patients with sarcomatoid carcinoma of the bladder who were treated at the Affiliated Hospital of Qingdao University between August 2010 and May 2021 were included in the study. A 1:2 propensity score matching system based on age, sex and pathological T stage was used for sarcomatoid and non-sarcomatoid carcinoma matching. Finally, 114 patients with BC were included. Patients with sarcomatoid carcinoma had worse 5-year cancer-specific survival (CSS) (69.1 vs. 86.9%; log-rank P=0.008) and recurrence-free survival (RFS) (64.1 vs. 83.6%; log-rank P=0.001) rates compared with patients with non-sarcomatoid carcinoma, as had the subgroup with muscle invasion. Multivariate analysis revealed sarcomatoid carcinoma as an independent prognostic factor. Patients with a low proportion of sarcomatoid components (1-50%) had a better prognosis than patients with a high proportion (>50%), and no significant difference was found compared with the non-sarcomatoid group. Overall, a proportion of sarcomatoid components >50% was a predictor of CSS and RFS. Sarcomatoid components markedly increased the risk of death and recurrence in muscle-invasive BC, but not in non-muscle-invasive BC. A higher proportion of sarcomatoid components was significantly associated with poorer survival.

Complete Response of Rare Sarcomatoid Upper Tract Urothelial Carcinoma Variant: Case Report and Literature Review

Infiltrating urothelial carcinoma sarcomatoid variant is a rare variant of urothelial carcinoma. We report a case of a 68-year-old female with a history of hematuria. CT scan with contrast showed a mass in the 1/3 distal of the right ureter. The biopsy result showed a high-grade infiltrating urothelial carcinoma. A radical nephroureterectomy was performed but at the follow-up after 3 months, there was a recurrent mass and gemcitabine-cisplatin chemotherapy was given. Since a high-grade infiltrating urothelial carcinoma sarcomatoid variant was an aggressive tumor, we need to give more attention to evaluating this tumor.

First report on establishment and characterization of a carcinosarcoma tumour cell line model of the bladder

Carcinosarcoma of the urinary bladder is a very rare and aggressive subtype of bladder cancer with poor prognosis. Characteristically carcinosarcomas exhibit biphasic nature with both epithelial and mesenchymal differentiation. Limited information is available regarding its clinical features and appropriate treatments due to its rarity. Development of tumour models can further our understanding of bladder carcinosarcoma. We report establishment and characterization of the first-ever bladder carcinosarcoma cell line MaS-3. It is established by the outgrow method from 86 year-old caucasian male who underwent a radical pelvic resection after neoadjuvant radiotherapy. MaS-3 showed carcinosarcoma profile with high conformity with to the original tumour in terms of immunocytochemistry. Proteome analysis also aligned the MaS-3 cell line with the carcinosarcoma specimen rather than corresponding non-malignant tissue. Chemotherapy sensitivity testing revealed a great sensitivity of MaS-3 growth to 5-Fluorouracil, Gemcitabine and Cisplatin, with almost no impact of Irinotecan. Additionally, the suitability of MaS-3 for 3D in vitro experiments was also demonstrated. The newly established cell line MaS-3 shows typical characteristics of the tumour and may thus be a useful in vitro model system for studying the tumour biology and developing future of treatments of this rare but very aggressive entity.

Sarcomatoid variant urothelial carcinoma of the bladder: a systematic review and meta-analysis of the clinicopathological features and survival outcomes

Background

A systematic review and meta-analysis was performed to compare the clinicopathological features and survival outcomes between sarcomatoid variant (SV)-urothelial carcinoma of the bladder (UCB) and conventional UCB (C-UCB).

Methods

A comprehensive search of PubMed, Embase, and Cochrane Library was performed. Endpoints included clinicopathological features and survival outcomes (overall survival [OS], cancer-specific survival [CSS], and progression-free survival [PFS]). The survival benefits of neoadjuvant chemotherapy (NAC) or adjuvant chemotherapy (AC) for SV-UCB also have been studied.

Results

A total of 8 observational studies were included. Patients with SV-UCB had a higher rate of ≥ stage pT3 (odds ratio [OR], 2.06; 95% confidence interval [CI], 1.64–2.59; p < 0.001) and a lower rate of concomitant carcinoma in situ (OR, 0.25; 95% CI, 0.09–0.72; p = 0.010). The other clinicopathological variables were similar between SV-UCB and C-UCB. With unadjusted data, patients with SV-UCB had a significant inferior OS (HR, 1.24; 95% CI, 1.07–1.44; p = 0.004) and CSS (HR, 2.08; 95% CI, 1.63–2.66; p < 0.001). However, after adjusted, SV-UCB had worse OS (HR, 1.41; 95% CI, 0.95–2.08; p = 0.090) and CSS (HR, 1.54; 95% CI, 0.95–2.52; p = 0.080) approaching the borderline of significance. For SV-UCB, NAC (HR, 0.73; 95% CI, 0.51–1.05; p = 0.090) and AC (HR, 0.88; 95% CI, 0.66–1.17; p = 0.370) seemed to have no benefit on OS.

Conclusions

Compared to C-UCB, SV-UCB was associated with more advanced disease and more inferior OS and CSS. NAC and AC had no survival benefit for SV-UCB.

Mesenchymal Neoplasms of the Genitourinary System: A Selected Review with Recent Advances in Clinical, Diagnostic, and Molecular Findings

Mesenchymal neoplasms of the genitourinary (GU) tract often pose considerable diagnostic challenges due to their wide morphologic spectrum, relative rarity, and unexpected incidence at GU sites. Soft tissue tumors arise throughout the GU tract, whether from adventitia surrounding or connective tissues within the kidneys, urinary bladder, and male and female genital organs. This selected article focuses on a subset of these lesions, ranging from benign to malignant and encompassing a range of patterns of mesenchymal differentiation, where recent scholarship has lent greater insight into their clinical, molecular, or diagnostic features.

Robotic Assisted Laparoscopic Partial Cystectomy as Treatment for Pseudosarcomatous Fibromyxoid Tumor of the Bladder

This case is of a 26 year old female evaluated for gross hematuria and suprapubic pain found to have a large bladder tumor. She subsequently underwent successful robotic assisted laparoscopic partial cystectomy. Pathology revealed pseudosarcomatous fibromyxoid tumor, an uncommon lesion that occurs most frequently among young females and must be distinguished from other malignant lesions, as treatment may differ. Partial cystectomy via robotic approach has never been described in the literature as a treatment option for this type of bladder lesion. In this case, the patient did exceptionally well upon follow-up. As such, robotic assisted laparoscopic partial cystectomy is presented a viable option for treatment of select patients with pseudosarcomatous fibromyxoid tumor.

Sarcomatoid Carcinoma of the Urinary Bladder

Sarcomatoid carcinoma of the urinary bladder (SCUB) is a rare and aggressive subtype of bladder cancer that has a poor prognosis. Limited information is available regarding its clinical features and appropriate treatments. A systematic literature search for published reports on SCUB was performed in the MEDLINE database using the key words "bladder cancer," "sarcomatoid carcinoma," and "carcinosarcoma.". The search resulted in the identification of 276 reports published from January 1960 to January 2014, of which 40 were ultimately included in the present review. No prospective study or clinical trial of SCUB was reported in English language studies. Of these studies, 2 cancer registry studies and 13 large case series, which had included ≥ 8 cases were identified. Seven single-institution studies contained adequate clinical follow-up information, and the rest had mainly focused on the pathologic features of the disease. Both the registry and the single-institution studies showed that patients with SCUB presented with a high histologic grade, advanced-stage disease, and a poor prognosis. Comparing the single-institution studies to the Surveillance, Epidemiology, and End Results cohorts, significant differences were found in the age at diagnosis, male-to-female ratio, tumor stage, treatment pattern (cystectomy, radiation, and chemotherapy), and outcomes, likely reflecting differences in referral and practice patterns. The tumor stage was identified as a significant predictor for cancer-specific survival. The results of the present study suggest that SCUB is not as rare as previously thought. Patients with SCUB should be referred to specialists or centers with extensive experience with this rare and serious disease.

Primary Sarcomatoid Tumor of the Bladder: A Different Entity but the Same Approach?

Bladder cancer remains a frequent cancer worldwide, and most tumors are diagnosed at localized stages. Urothelial carcinoma (UC) accounts for 90% of bladder cancer cases. Sarcomatoid carcinoma (SaC) of the bladder is a rare variant (0.5% of total bladder cancers) characterized by 2 components based on histology; the epithelial and mesenchymal phenotypes, which can be easily differentiated by immunohistochemistry. SaC has similar epidemiologic features to UC but different behavior, aggressiveness, and prognosis. In this review, we summarize the main differences between UC bladder cancers and SaC subtypes. The therapeutic strategies used in SaC today do not differ much from those used for the urothelial variant. However, there is still no standard treatment--the result of a lack of clinical trials for the sarcomatoid variant. Further multicenter comparative studies are needed to devise a better treatment strategy for patients with this rare histologic tumor subtype.

Pseudosarcomatous myofibroblastic proliferation of the urinary bladder: a rare entity

Pseudosarcomatous myofibroblastic proliferations are very unusual entities of unknown etiology. Despite its benign nature, this entity can easily be misdiagnosed (both clinically and histologically) as a malignant neoplasm. Hereby, we report a case of a 15-year-old woman who presented to our hospital with a broad-based polypoid mass located in the left posterior wall of the urinary bladder. The patient underwent a transurethral resection of the lesion. Morphologic and immunohistochemical findings suggested the diagnosis of pseudosarcomatous myofibroblastic proliferation. The patient is free of recurrence 5 years after surgery.

Postoperative spindle cell nodule of the bladder: A case report and review of the literature

Postoperative spindle cell nodule (PSCN) of the bladder is a rare condition. It is a type of benign lesion frequently misdiagnosed as sarcomatoid carcinoma on the basis of similar cell morphology. The present report describes a tumor affecting a 71-year-old male who had undergone three transurethral resections. Pathological results suggested a diagnosis of sarcomatoid carcinoma, and therefore a radical cystectomy was performed. However, the tumor was later identified as a PSCN. In order to prevent such misdiagnosis, this study reviews relevant articles concerning postoperative spindle cell nodules of the bladder and compares PSCN and sarcomatoid carcinomas to identify specific characteristics of PSCN. Finally, the report emphasizes the importance of careful pathological examination in rare cases such as PSCN and sarcomatoid carcinoma.

Low-grade myofibroblastic proliferations of the urinary bladder

CONTEXT

Myofibroblastic proliferations of the urinary bladder, which share some similarities with nodular fasciitis, were first reported in 1980. Since then, they have had several designations, the most frequently used being inflammatory myofibroblastic tumor. Based on both histopathologic and prognostic grounds, some authors prefer the term pseudosarcomatous myofibroblastic proliferation, at least for some of the proliferations. These same scientists also assimilate the so-called postoperative spindle cell nodules with the pseudosarcomatous myofibroblastic proliferations. Little is known about these low-grade myofibroblastic proliferations.

OBJECTIVES

To review the literature about low-grade myofibroblastic proliferations occurring in the urinary bladder.

DATA SOURCES

Textbooks and literature review. We obtained most of the clinicopathologic peculiarities from a patient population composed of the most-relevant, previously reported cases.

CONCLUSIONS

The low-grade myofibroblastic proliferations of the urinary bladder are rare lesions affecting males more often than they do females. The most-common signs and symptoms are hematuria and dysuria. Histopathologically, they are spindle cell proliferations in a loose myxoid stroma, even though compact proliferations or hypocellular fibrous patterns can be found. Immunohistochemistry is quite nonspecific, except for ALK-1 positivity (20%-89%). Fluorescence in situ hybridization has demonstrated clonal genetic aberrations involving the ALK gene in 50% to 60% of cases. After surgery, only 6% of patients experience local recurrence, without metastases or deaths from the disease. Malignant transformation has been reported exceptionally. These myofibroblastic proliferations are probably part of a continuum with, at one end, benign pseudosarcomatous proliferations and, at the opposite end, more-aggressive lesions. Because of the frequently indolent clinical course, aggressive treatment would be unjustified.

[Pseudosarcomatous myofibroblastic proliferation of the bladder]

Myofibroblastic proliferations of the bladder in adults are unusual lesions with a benign course. These proliferations, whether spontaneous or secondary to instrumentation, have identical morphology and behaviour. Histologically, similar lesions have been reported in the literature using different names, such as inflammatory pseudotumour, pseudosarcomatous fibromyxoid tumour, nodular fasciitis, postoperative spindle cell nodule... Recently, some authors proposed that these lesions are similar enough to be considered the same entity, designated as "pseudosarcomatous myofibroblastic proliferation" and insisted on the necessity to distinguish them from the inflammatory myofibroblastic tumour of the childhood. The latter, recently recognized as tumour, has a malignant potential and is capable of giving metastases. We describe the case of a 17-year-old man who presented a vesical mass. The histopathological study concluded to a pseudosarcomatous myofibroblastic proliferation. We discuss, through a literature review, the relationship of this lesion with inflammatory myofibroblastic tumour and its main differential diagnoses.

[Case report: a patient with bladder sarcoma exclusively treated with transurethral resection with long-term follow-up]

Sarcoma is a rare malignant lesion in the urinary bladder and remains unknown of its natural history. We report a case of primary bladder sarcoma with long-term follow-up. A 35-year-old man suddenly presented with severely gross hematuria. Computer tomography was showed solitary lesion at the anterior wall of the urinary bladder without distant metastases. Transurethral resection of the bladder tumor (TURBT) was performed. Pathologic findings demonstrated sarcoma in the urinary bladder without remnant lesions. Immunohistochemical staining using conventional antibodies was not classified as the origin of this sarcoma. There have been no signs of recurrence during twenty years' follow-up after the treatment.

Inflammatory myofibroblastic tumors of the genitourinary tract--single entity or continuum?

PURPOSE

Inflammatory myofibroblastic tumor of the genitourinary tract is a spindled soft tissue lesion that is often mistaken for sarcoma. These tumors have been described in numerous sites in the body and have been assigned many names. The relationship between inflammatory myofibroblastic tumor and other morphologically similar entities has been a long-standing source of controversy. We investigated whether inflammatory myofibroblastic tumors in adults and children are the same entity, and whether inflammatory myofibroblastic tumor is part of a biological spectrum that includes benign and malignant entities at opposite ends.

MATERIALS AND METHODS

We performed an extensive review of the literature.

RESULTS

The literature suggests that with evidence of anaplastic lymphoma kinase rearrangement and expression, the lesion is neoplastic rather than reactive, differentiating it from previously described lesions.

CONCLUSIONS

Inflammatory myofibroblastic tumor of the genitourinary tract should be considered a neoplasm of uncertain malignant potential, and routine surveillance and close clinical followup are recommended. Aggressive therapy (radical cystectomy, radiation or chemotherapy) is unwarranted given the indolent and often benign clinical course for the majority of cases. To understand the diagnostic and prognostic implications future emphasis should be placed on the link between genetic abnormalities, and clinical course, therapeutic response and ultimate outcome.

Pseudosarcomatous myofibroblastic proliferation of the urinary bladder

Pseudosarcomatous myofibroblastic proliferation (PMP) of the bladder is a rare, benign, and proliferative lesion of the submucosal stroma. We report a 38-year-old female patient who was initially diagnosed with urothelial carcinoma of the urinary bladder under intravenous pyelography. Bladder tumor was resected by the transurethral method, and pathology disclosed a picture compatible with pseudosarcomatous myofibroblastic proliferation. However, local recurrence was found 2 months later, and tumor resection was performed again. The patient has been followed-up at our outpatient department for a year without any evidence of recurrence.