Pseudosarcomatous fibromyxoid tumor of the urinary bladder and prostate: immunohistochemical, ultrastructural, and DNA flow cytometric analyses of nine cases

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.

Locally advanced solitary fibrous tumour of the prostate

Solitary fibrous tumours (SFTs) are rare mesenchymal neoplasms composed of spindle cells, most often occurring in the pleura. SFTs arising from the prostate are exceptionally rare, with only around 40 cases reported in literature to date. We report a man in his 60s who was referred to our clinic for elevated prostate-specific antigen and presented with mild obstructive lower urinary tract and defecatory symptoms. Prostate needle-core biopsy revealed neoplastic spindle cells that strongly expressed CD34. Cross-sectional imaging demonstrated a 12 cm locally advanced heterogeneous prostate mass with intravesical extension and mass effect on the anterior rectum. Radical cystoprostatectomy with orthotopic neobladder reconstruction was performed, and the diagnosis of primary prostatic SFT was made based on histological characteristics and immunophenotyping. We present diagnostic, clinical management and prognostic considerations in patients with primary prostatic SFT.

Development and validation of a prognostic nomogram for predicting overall survival in patients with primary bladder sarcoma: a SEER-based retrospective study

Background

Primary bladder sarcoma (PBS) is a rare malignant tumor of the bladder with a poor prognosis, and its disease course is inadequately understood. Therefore, our study aimed to establish a prognostic model to determine individualized prognosis of patients with PBS.

Patients and Methods

Data of 866 patients with PBS, registered from 1973 to 2015, were extracted from the surveillance, epidemiology, and end result (SEER) database. The patients included were randomly split into a training (n = 608) and a validation set (n = 258). Univariate and multivariate Cox regression analyses were employed to identify the important independent prognostic factors. A nomogram was then established to predict overall survival (OS). Using calibration curves, receiver operating characteristic curves, concordance index (C-index), decision curve analysis (DCA), net reclassification improvement (NRI) and integrated discrimination improvement (IDI), the performance of the nomogram was internally validated. We compared the nomogram with the TNM staging system. The application of the risk stratification system was tested using Kaplan–Meier survival analysis.

Results

Age at diagnosis, T-stage, N-stage, M-stage, and tumor size were identified as independent predictors of OS. C-index of the training cohort were 0.675, 0.670, 0.671 for 1-, 3- and 5-year OS, respectively. And that in the validation cohort were 0.701, 0.684, 0.679, respectively. Calibration curves also showed great prediction accuracy. In comparison with TNM staging system, improved net benefits in DCA, evaluated NRI and IDI were obtained. The risk stratification system can significantly distinguish the patients with different survival risk.

Conclusion

A prognostic nomogram was developed and validated in the present study to predict the prognosis of the PBS patients. It may assist clinicians in evaluating the risk factors of patients and formulating an optimal individualized treatment strategy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-021-00929-x.

Pseudosarcomatous myofibroblastic proliferations of the urinary bladder are neoplasms characterized by recurrent FN1-ALK fusions

Pseudosarcomatous myofibroblastic proliferation is a descriptive term that designates a group of clinically indolent genitourinary lesions that most commonly arise in the urinary bladder. Given that pseudosarcomatous myofibroblastic proliferation may show morphologic overlap with inflammatory myofibroblastic tumor, the relationship, if any, between the two entities has been unclear. Moreover, pseudosarcomatous myofibroblastic proliferations are known to be positive for ALK immunohistochemistry in a subset of cases, although an inconsistent association with ALK rearrangement (ranging from 0 to 60%) has been reported. The objectives of this study were to determine the frequency of ALK rearrangement and to identify fusion partners using fluorescence in situ hybridization (FISH) and targeted RNA sequencing studies in a contemporary series of 30 pseudosarcomatous myofibroblastic proliferations of the urinary bladder, as well as to investigate ROS1 status by immunohistochemistry. ALK immunohistochemistry was positive in 70% (21/30) of pseudosarcomatous myofibroblastic proliferations; ROS1 immunohistochemistry was consistently negative (0/28). ALK rearrangements were detected by FISH in 86% (18/21) of cases, correlating with ALK immunohistochemical positivity in all but 3 cases. Of eight cases confirmed to be ALK rearranged by FISH, targeted RNA-sequencing detected FN1-ALK fusions in seven (88%) cases, which involved exons 20-26 of FN1 (5') and exon 18-19 of ALK (3'). In conclusion, ALK rearrangements are frequent in pseudosarcomatous myofibroblastic proliferations, typically involving exon 19, and FN1 appears to be a consistent fusion partner. Given the significant clinicopathologic differences between inflammatory myofibroblastic tumor and pseudosarcomatous myofibroblastic proliferation, our findings provide further support for classification of pseudosarcomatous myofibroblastic proliferation as a distinct clinicopathologic entity, and propose the alternate terminology "pseudosarcomatous myofibroblastic neoplasm of the genitourinary tract."

A Rare Case of Inflammatory Myofibroblastic Tumor of the Prostate and Review of the Literature

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a rare type of soft-tissue neoplasm. IMT of the urinary tract is more common in the bladder and kidneys. Prostatic IMT is extremely rare.

CASE REPORT

We present a rare case of IMT of the prostate and a literature review on this condition. The patient was a 72-year-old man who presented with urinary symptoms. Transrectal needle biopsy of the prostate revealed prostatic adenocarcinoma with nodular hyperplasia. Radical prostatectomy revealed IMT without residual adenocarcinoma. On immunohistochemical examination, the tumor cells showed positive immunoreactivity for α-smooth muscle actin, CD10, CD34, and desmin but negative immunoreactivities for anaplastic lymphoma kinase (ALK), receptor tyrosine kinase (c-KIT), and S-100 protein. The patient underwent regular follow-up examination. No recurrence was observed 4 months after the diagnosis.

CONCLUSION

This was a case of IMT arising in the prostate. Pathologists should be aware of such an entity whenever they see spindle-cell lesions in the transrectal needle biopsy of the prostate.

A Rare Case of Inflammatory Myofibroblastic Tumor of the Prostate and Review of the Literature

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a rare type of soft-tissue neoplasm. IMT of the urinary tract is more common in the bladder and kidneys. Prostatic IMT is extremely rare.

CASE REPORT

We present a rare case of IMT of the prostate and a literature review on this condition. The patient was a 72-year-old man who presented with urinary symptoms. Transrectal needle biopsy of the prostate revealed prostatic adenocarcinoma with nodular hyperplasia. Radical prostatectomy revealed IMT without residual adenocarcinoma. On immunohistochemical examination, the tumor cells showed positive immunoreactivity for α-smooth muscle actin, CD10, CD34, and desmin but negative immunoreactivities for anaplastic lymphoma kinase (ALK), receptor tyrosine kinase (c-KIT), and S-100 protein. The patient underwent regular follow-up examination. No recurrence was observed 4 months after the diagnosis.

CONCLUSION

This was a case of IMT arising in the prostate. Pathologists should be aware of such an entity whenever they see spindle-cell lesions in the transrectal needle biopsy of the prostate.

A Fibromyxoid Stromal Response is Associated with Muscle Invasion in Canine Urothelial Carcinoma

Canine urothelial carcinoma (UC) is the most common type of cancer of the lower urinary tract and tends to affect elderly neutered female dogs, with a high predisposition for Scottish terriers. Tumour stroma, inflammation and necrosis are poorly characterized in canine UC and their role as prognostic factors is unknown. The aims of this study were to (1) assess histologically 381 canine UCs, with emphasis on myxoid tumour stroma, inflammation and necrosis and (2) assess possible associations between these features and the available epidemiological data as well as bladder wall muscle invasion. In 103 of 381 (27%) cases, the stroma was mixed collagenous and myxoid (fibromyxoid), which was strongly associated with invasive growth of muscle (P <0.0001). Peritumoural and intratumoural inflammation was present in 308 of 345 (89%) and 287 of 381 (75%) cases, respectively, and was mostly mild and lymphoplasmacytic. One hundred and fifteen of the 381 (30%) cases showed a variable eosinophilic inflammation and 58 of 381 (15%) presented with formations of one or several lymphoid follicles. Twenty-four percent (91 of 381) of cases had tumour necrosis, which was typically mild. In 83 of 91 (91%) cases, the necrosis was comedo-like. Moderate to severe tumour necrosis was associated with the presence of moderate to predominant fibromyxoid tumour stroma (P <0.02). The results of this study indicate that fibromyxoid stroma is common in canine UC and is a strong indicator for invasive growth of muscle, which is consistent with a poor prognosis. Based on histomorphology, tumour necrosis in canine UC is best described as comedonecrosis.

Pseudosarcomatous myofibroblastic proliferations of the genitourinary tract are genetically different from nodular fasciitis and lack USP6, ROS1 and ETV6 gene rearrangements

AIMS

Pseudosarcomatous myofibroblastic proliferations of the genitourinary tract have a debatable relationship with inflammatory myofibroblastic tumour (generally lacking ALK rearrangement); however, they share several overlapping features with nodular fasciitis of soft tissue. As rearrangement of the USP6 gene has been recently recognised as a recurrent alteration in soft tissue nodular fasciitis, and several other alternative gene fusions have been recently recognised in inflammatory myofibroblastic tumour, the aim of this study was to investigate whether USP6, ROS1 or ETV6 rearrangements were present in these lesions (12 cases).

METHODS AND RESULTS

Fluorescence in-situ hybridisation analysis was performed by the use of bacterial artificial chromosome-derived break-apart probes against USP6, ROS1, and ETV6. Two cases with adequate genetic material from recent paraffin tissue blocks were also tested by use of a solid tumour gene fusion detection assay via next-generation sequencing, targeting >50 known genes involved in recurrent fusions. None of the genitourinary pseudosarcomatous myofibroblastic proliferations was found to harbour USP6 (0/12), ROS1 (0/8) or ETV6 (0/7) rearrangements, and no gene fusions were detected in two cases studied by sequencing.

CONCLUSIONS

Despite overlap in histological and immunohistochemical features between pseudosarcomatous myofibroblastic proliferation and nodular fasciitis, these tumours lack the recently recognised USP6 rearrangements that occur in nodular fasciitis, as well as alternative fusions found in ALK-negative inflammatory myofibroblastic tumours. At present, this diagnosis remains based primarily on clinical, histological and immunohistochemical features.

Mesenchymal tumors of the prostate

Mesenchymal tumors of the prostate are rare but often cause considerable diagnostic difficulty when encountered. These may be either benign or malignant and can arise within the prostate gland or in adjacent tissues. This review covers prostatic stromal proliferations (prostatic stromal tumor of uncertain malignant potential and stromal sarcoma), solitary fibrous tumor, myofibroblastic proliferations, smooth muscle neoplasms (leiomyoma and leiomyosarcoma), gastrointestinal stromal tumor, schwannoma, rhabdomyosarcoma, sarcomatoid carcinoma, postradiation sarcoma, and mixed epithelial stromal tumor of the seminal vesicle. Differential diagnostic considerations are emphasized, including descriptions of helpful histological and/or clinical clues and the use of adjuvant diagnostic techniques.

Clinico-radiological and Pathological Characteristics of Inflammatory Myofibroblastic Tumors in Children: A Retrospective Study

Purpose

Inflammatory myofibroblastic tumors (IMTs) are rare, benign lesions most often seen in the lung of young adults but can occur in children, in various sites. They mimic, clinically and radiologically, malignant tumors - especially sarcomas and lymphomas. The aim was to review the clinical, radiological, and pathological data of children with a diagnosis of IMT referred to our department.

Materials and Methods

This retrospective study was conducted at the Department of Medical and Paediatric Oncology, Regional Cancer Centre, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir, India from January 2014 to December 2015.

Results

Among 288 pediatric tumors registered during the study, 5 (1.73%) had the diagnosis of IMTs. The main symptoms were abdominal distension and pain in 60% (three cases), breathlessness and cough in 20% (one case), and right axillary area swelling in 20% (one case). In three patients, complete surgical excision was done, whereas another patient with retroperitoneal mass had the residual disease and received chemotherapy followed by complete second surgery. In the case of mediastinal IMT, surgery was followed by local radiotherapy. At present, four patients are disease-free and one patient with mediastinal IMT has the residual progressive disease.

Conclusion

On presentation, IMT can constitute a formidable challenge, from diagnosis through to treatment.

Polypoid Carcinoma of the Oropharynx with Stromal Ossifying Myofibroblastic Proliferation: A Case Report and Literature Review

A 76-year-old man reported a worsening difficulty in swallowing, leading to the inability to eat. Physical examination and CT scan revealed a polypoid mass on the posterior oropharynx and obstructing the oropharyngeal space. Histologically, the surface was ulcerated. In the underlying necrotic rim, there was active granulation tissue, and a proliferation of voluminous, globoid elements with hyperchromatic and irregular nucleus, sometimes arranged in a alveolar aggregate. The core of the lesion contained spindle-like myoid elements in interwoven bundles, with trabeculae of osteoid matrix maturing into calcified bone. Immunohistochemistry documented positivity for cytokeratins, epithelial membrane antigen, and P63 in the globoid elements beneath the necrotic rim; strong and diffuse expression of vimentin, smooth muscle actin, and CD99 and BCL2 in the spindle elements; and complete negativity for cytokeratin 5/6, high molecular weight cytokeratin (clone 34βE12), S100, muscle-specific actin, desmin, CD117, and anaplastic lymphoma kinase. The lesion was morphologically and immunophenotypically classified as a polypoid oropharyngeal carcinoma with ossifying myofibroblastic stromal proliferation.

Embryonal rhabdomyosarcoma of the adult urinary bladder: a rare case report of misclassification as inflammatory myofibroblastic tumor

Embryonal rhabdomyosarcoma (ERMS) of the adult urinary bladder is a rare malignant tumour. Inflammatory myofibroblastic tumour (IMT) of the bladder is a benign genitourinary tumour that may appear variable histologically but usually lacks unequivocal malignant traits. Techniques like flow cytometry and immunohistochemistry may be used to differentiate these two tumours. Our patient, a 46-year-old male, had rapidly recurring lower urinary tract symptoms after two transurethral resections of the prostate. He subsequently underwent a transvesical prostatectomy which showed IMT on histology. However, his symptoms did not resolve and an open resection done at our institution revealed a 6 cm tumour arising from the right bladder neck. This time, histology was ERMS with diffuse anaplasia of the bladder. Rapid recurrence of urinary symptoms with prostate regrowth after surgery is unusual. Differential diagnoses of uncommon bladder malignancies should be considered if there is an inconsistent clinical course as treatment approaches are different.

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.

Non-epithelial neoplasms of the prostate

Non-epithelial prostatic neoplasms are infrequent and cover a broad array of entities that include both benign and highly aggressive tumours. Because they are very infrequent, there is often limited understanding of them, and the recognition of these entities, when encountered, may pose a diagnostic challenge, owing to histological overlap between them or their rarity. Most lesions in this category are mesenchymal in origin, such as prostatic stromal tumours arising from specialized prostatic stroma, smooth muscle tumours, both benign and malignant, and solitary fibrous tumours. Less commonly occurring tumours include neural, germ cell and melanocytic tumours that may be derived from cells not normally present in the prostate. Some tumours have well-established extraprostatic counterparts and, when encountered, are more commonly extraprostatic/secondary in origin; these include gastrointestinal stromal tumours and most haematopoietic tumours. The majority of tumours are characterized by a spindle cell pattern with significant overlap in morphological features. In this setting, appropriate use of immunohistochemistry and molecular studies are often necessary for accurate diagnosis, prognosis, or prediction for therapy. This review addresses and updates the clinicopathological features of the entire spectrum of non-epithelial tumours with an approach to the histological diagnosis.

Nonepithelial Tumors and Tumor-Like Lesions of the Prostate Gland

Many significant benign and malignant nonepithelial tumors and stromal tumor-like lesions arise in the prostate gland. Although such lesions are rare, their recognition by the pathologist is essential because their treatment and prognosis are quite variable. In this review, lesions of the specialized prostatic stroma, that is, lesions that can be seen in the stroma of the prostate but not in that of other organs, except for the phyllodes type of lesions, are discussed. Benign and malignant lesions of the soft tissues that occur in the stroma of other organs and are seen with some frequency in the prostate are also discussed. Few of the rarer soft tissue lesions are mentioned. Lesions and tumors with melanocytic differentiation, hematopoietic derivation, and germ cell tumors are described. It is hoped that this review will serve as a useful reference when encountering some of these lesions, all of which are referenced to their original and subsequent reports. Some non-English language references are also cited to reflect the international recognition of these lesions or to give credit to the author who first described the entity.

Significance of inflammatory pseudotumors in patients with a history of bladder cancer

OBJECTIVE

To study the significance of inflammatory pseudotumor (IPT) in patients with a history of bladder cancer.

METHODS

We surveyed our hospital database for patients who developed IPT during follow-up of bladder cancer. The original histologic blocks were reviewed and immunostained for vimentin, anaplastic large cell lymphoma (ALK), and pancytokeratin.

RESULTS

Between the years 1988 and 2005, a total of 809 patients were registered in the database, and 16 patients (2%) developed IPT during follow-up. All patients had initial high-grade tumor. Immunostaining for vimentin was positive in all patients, ALK was negative in all patients, and pancytokeratin positive in only 2 patients. During follow-up, 12 patients (75%) developed tumor recurrence, 9 patients (56%) tumor progression, and 6 patients (37.5%) died of bladder cancer. Median period from the finding of IPT to tumor recurrence was 16 months, to progression 7 months, and to mortality 26 months.

CONCLUSIONS

The finding of IPT in a patient with a history of bladder cancer is associated with a high risk of tumor recurrence, progression, and cancer-related mortality. Second- and possibly third-look bladder biopsies should be considered. The unique characteristics of IPT in patients with a history of bladder cancer suggest that this is a separate disease entity.

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.

Low-grade pelvic masses with spindle cell and fibroblastic proliferation: a case report

BACKGROUND

Abdominal-pelvic masses containing spindle cell and fibroblastic proliferation are very rare. Since scant studies have reported on the pathologic characteristics inherent in this disease, appropriate clinical management is undetermined.

CASE PRESENTATION

We report on an 87 year-old woman who presented with large abdominal pelvic masses, ascites, ureteral obstruction, and an elevated CA-125 serum level. The patient underwent surgical resection of the lesions and has since done very well. Final pathology revealed a low-grade ovarian tumor with spindle cell and fibroblastic proliferation.

CONCLUSION

To the best of our knowledge, this appears to be the only reported clinical case of a patient with this rare histology.

Pseudosarcomatous and sarcomatous proliferations of the bladder

Pseudosarcomatous fibromyxoid tumor (PFT), postoperative spindle cell nodule (PSN), sarcoma, and sarcomatoid carcinoma of the bladder are frequently difficult to distinguish histopathologically with significant differences in disease-related outcomes. A retrospective review of our pathology registry over the last 25 years identified 7 PFT, 10 PSN, 18 primary bladder sarcomas, and 17 sarcomatoid carcinomas. Most patients with PFT, PSN, sarcoma, and sarcomatoid carcinoma were diagnosed between the ages of 50 to 60 years with PFT and PSN most commonly detected in women. A previous history of urological instrumentation and bladder cancer was present in all patients with PSN but none of the patients with PFT. Pseudosarcomatous fibromyxoid tumors were characterized by a tissue culture-like proliferation of myofibroblastic cells with focal atypia and overall cytoarchitectural features mimicking nodular fasciitis. Sarcomas and sarcomatoid carcinomas exhibited cellular atypia, mitotic activity with atypical mitosis, and the presence of necrosis. Transurethral resection was sufficient to control all PFT and PSN with no evidence of distant metastatic spread. In contrast, local recurrences and distant metastases frequently occurred in patients with primary sarcoma and sarcomatoid carcinoma despite aggressive surgical management, which was often combined with neoadjuvant chemotherapy (50% and 65% disease-specific mortality, respectively). Pseudosarcomatous fibromyxoid tumor and PSN have unique clinical and pathologic features that allow their distinction from primary bladder sarcoma and sarcomatoid carcinoma.

Inflammatory pseudotumor of urinary bladder - a diagnostic and management dilemma

Inflammatory pseudotumors (IPT) are uncommon, benign, non-epithelial tumors of the urinary bladder. Only less than 30 cases have been reported so far in world's literature. The transititional cell carcinoma constitutes 90% of malignant epithelial tumors of urinary bladder. Large, endoscopically unresectable tumors require radical surgery. IPT resemble such tumors, morphologically, radiologically and clinically. The benign nature of this tumor warrants conservative surgical management, either transurethral resection or partial cystectomy. Awareness of this entity and its inclusion in the differential diagnosis may prevent unnecessary radical surgery. We report an unusual case of inflammatory pseudotumor of urinary bladder because of its diagnostic and management dilemma.

Inflammatory myofibroblastic tumors of the urinary tract: a clinicopathologic study of 46 cases, including a malignant example inflammatory fibrosarcoma and a subset associated with high-grade urothelial carcinoma

Inflammatory myofibroblastic tumor (IMT) of the urinary tract, also termed postoperative spindle cell nodule, inflammatory pseudotumor, and pseudosarcomatous fibromyxoid tumor, is rare and in the past was believed to reflect diverse entities. We reviewed a series of 46 IMTs arising in the ureter, bladder, and prostate, derived primarily from a large consultation practice. There were 30 male and 16 females aged 3 to 89 years (mean 53.6). Lesions were 1.2 to 12 cm (mean 4.2). There was a history of recent prior instrumentation in 8 cases. Morphology was similar to that previously described for IMT occurring in this region, with the exception of 1 case that focally appeared sarcomatous. Polypoid cystitis coexisted in 5 patients (11%). Mitoses were typically scant (0 to 20/10 hpf, mean 1). Necrosis was seen in 14 (30%) cases. Invasion of the muscularis propria was documented in 19 (41%). By immunohistochemistry (IHC), lesions at least focally expressed anaplastic lymphoma kinase (ALK) (20/35, 57%), AE1/3 (25/34, 73%), CAM5.2 (10/15, 67%), CK18 (6/6, 100%), actin (23/25, 92%), desmin (15/19, 79%), calponin (6/7, 86%), caldesmon (4/7, 57%, rare cells), p53 (10/13, 77%), and most lacked S100 (0/14), CD34 (0/13), CD117 (2/13, 15%), CD21 (0/5), and CD23 (0/3). ALK gene alterations were detected by fluorescence in situ hybridization (FISH) in 13/18 (72%) tested cases, including 2 with prior instrumentation; 13/18 (72%) showed agreement between FISH ALK results and ALK protein results by IHC. Most bladder IMTs were managed locally, but partial cystectomy was performed as the initial management in 7 cases and cystectomy in 1 (1 IMT was initially misinterpreted as carcinoma, 1 IMT was found incidentally as a separate lesion in a cystectomy specimen performed for urothelial carcinoma). Follow-up was available in 32 cases (range 3 to 120 mo; mean 33; median 24). There were 10 patients with recurrences (2 with 2 recurrences). Recurrences were unassociated with muscle invasion or with ALK alterations. In 2 cases, tumors of the urinary tract (TURs) showing IMT preceded (1 and 2 mo, respectively) TURs showing sarcomatoid carcinoma with high-grade invasive urothelial carcinoma accompanied with separate fragments of IMT. Even on re-review the IMT in these 2 cases were morphologically indistinguishable from other cases of IMT, with FISH demonstrating ALK alterations in the IMT areas in one of them. Both these patients died of their carcinomas. Lastly, there was 1 tumor with many morphological features of IMT and an ALK rearrangement, yet overtly sarcomatous. This case arose postirradiation for prostate cancer 4 years before the development of the lesion, with tumor recurrence at 4 months and death from intra-abdominal metastatic disease at 9 months. In summary, urinary tract IMTs are rare and share many features with counterparts in other sites, displaying similar morphology and immunogenotypic features whether de novo or postinstrumentation. Typical IMTs can be locally aggressive, sometimes requiring radical surgical resection, but none of our typical cases metastasized, although they can rarely arise contemporaneously with sarcomatoid urothelial carcinomas. For these reasons, close follow-up is warranted.

Review of the M.D. Anderson experience in the treatment of bladder sarcoma

OBJECTIVE

To assess the histologic subtypes, clinical presentations, treatment approaches, and treatment-related outcomes of patients with bladder sarcoma.

METHODS

Between January 1985 and July 2004, 19 patients (12 men and 7 women) with primary bladder sarcoma were evaluated at the University of Texas M.D. Anderson Cancer Center. Median follow-up duration was 72 months (range 3-141).

RESULTS

The median age of patients at presentation was 57 years (range 22-94). The histologic subtypes of bladder sarcoma were leiomyosarcoma (N = 14), angiosarcoma (N = 3), and unclassified sarcoma (N = 2). The clinical presentation consisted of gross, painless hematuria in 79% of patients, lower urinary tract symptoms in 16%, and microhematuria in 5%. The primary treatment modalities used were surgery in 16 (84%) patients, chemotherapy in 2 (11%), and palliation in 1 (5%). The rate of local and distal recurrence was 16% and 53%, respectively. The most common sites of distant metastases were the lungs, bone, brain, and liver. The 5-year disease-specific survival rate was 59%, with a median survival duration of 6 years. There was no statistically significant difference in disease-specific survival between patients with bladder leiomyosarcoma compared to other sarcoma subtypes (P = 0.149). Lymphovascular invasion (P = 0.03) and lymphatic metastasis (P = 0.03) were associated with disease-specific survival, and surgical margin status was associated with recurrence-free (P = 0.04), disease-specific (P = 0.03), and overall survival (P = 0.005).

CONCLUSIONS

Bladder sarcoma is a highly aggressive malignancy, regardless of its histologic subtype. Surgical margin status is an important determinant of survival.

Pseudosarcomatous Myofibroblastic Proliferations of the Bladder

Inflammatory pseudotumor or pseudosarcomatous fibromyxoid tumor and postoperative spindle cell nodule of the bladder are unusual lesions of uncertain pathogenesis which share overlapping, if not identical, histologic features. We present our experience with 42 cases, the largest series to date, to study the etio-pathogenesis, histologic features, biologic behavior and relationship to "inflammatory myofibroblastic tumor" of childhood. Patients ranged in age from 7 to 77 years (mean 47 y) and males predominated (3.2:1). Most patients presented with hematuria (31/42). Common associations were smoking (10/30) and previous instrumentation or surgery (9/42). The clinicopathologic features of patients having or not having prior instrumentation were identical. Grossly the lesions were polypoid or nodular and involved any portion of bladder wall, most commonly the dome (9/27) and measured 1 to 10 cm (mean 4 cm). They were composed of spindled and stellate cells arranged in a myxoid background with numerous inflammatory cells. Myxoid hypocellular areas were more pronounced near the mucosal surface with greater cellularity and a fascicular arrangement in the deep aspect of the lesion. "Atypical" features included mitotic activity (0 to 20/10 HPF; mean 2/10 HPF; median 1/10 HPF; none atypical), necrosis (22/42), and extension into muscularis propria (28/32) or perivesicular fat (3/8). Lesions were positive for cytokeratin (31/33), SMA (23/34), desmin (21/35), and Alk-1 protein (12/26). FISH confirmed the Alk-1 translocation in 4/6 cases. Treatment included transurethral resection (30/42), partial cystectomy (9/42), and total cystectomy (3/42). Initial diagnostic error resulted in radiotherapy and chemotherapy in 3 patients. Follow-up was available in 28 patients. (range 3 to 93 mo; median 25 mo). Three patients developed recurrences, but none had metastases. Because the clinicopathologic features of lesions associated with and without instrumentation were similar and inseparable, we believe they are essentially the same entity, and propose the term pseudosarcomatous myofibroblastic proliferation. The preponderance of evidence which includes the extravesical growth, local recurrence, and Alk-1 gene translocation in some cases suggests perhaps a neoplastic process with limited growth potential. Even in the face of atypical histologic features (muscle invasion and necrosis) the prognosis is excellent. Despite the Alk-1 gene translocation, there continues to be sufficient evidence for regarding these as distinct from the so-called inflammatory myofibroblastic tumor of childhood.

ALK expression in pseudosarcomatous myofibroblastic proliferations of the genitourinary tract

AIMS

Pseudosarcomatous myofibroblastic proliferation of the genitourinary tract is rare and may develop after trauma or spontaneously. The aim of this study was to characterize further the clinicopathological features of these lesions and to examine their relationship to inflammatory myofibroblastic tumour (IMT).

METHODS AND RESULTS

Twenty-seven cases of pseudosarcomatous myofibroblastic proliferation were analysed. There were seven males and 20 females; median age was 37 years (range 16-88). Most lesions were from the bladder (n = 21), while others were in the urethra, vulva, vagina, rectum and retrovesical space. Median tumour size was 30 mm (range 6-120 mm). Seven cases (25%) had a history of prior trauma or surgery. Three cases recurred locally but not destructively. The tumours had fasciitis-like features including bland spindle cells with evenly distributed chromatin, admixed inflammatory cells (mainly lymphocytes) and often a myxoid stroma. Immunohistochemistry showed positivity for smooth muscle actin in 14/20 cases, keratin in 8/19, desmin in 7/20 and anaplastic lymphoma kinase (ALK) in 10/21 cases. Fluorescent in situ hybridization was performed in six ALK+ cases; all were negative for ALK gene rearrangement.

CONCLUSIONS

Pseudosarcomatous myofibroblastic proliferations of the genitourinary tract may show ALK immunopositivity but do not show consistent ALK rearrangement. Given subtle morphological differences and more consistently benign behaviour, their relationship to inflammatory myofibroblastic tumour at other sites remains uncertain.

Inflammatory pseudotumor of urachus mimicking invasive carcinoma of bladder

Inflammatory pseudotumor of the bladder is a rare benign lesion of unknown etiology. We present a new case of pseudotumor of the urachus in a 16-year-old boy with no significant urologic history. This benign condition mimics invasive malignant tumors of the urinary bladder, and aggressive surgery is the basic treatment modality.

Cardiac pseudosarcomatous fibromyxoid tumor: a review of the literature

A cardiac pseudosarcomatous fibromyxoid tumor (PFT) is described in a previously healthy 35-year-old man, together with a review of the literature. Pseudosarcomatous fibromyxoid tumor is within the spectrum of inflammatory (myofibroblastic) pseudotumors. It has previously been described predominantly within the genitourinary tract and respiratory tract. Inflammatory pseudotumor is rare as a cardiac tumor, and cardiac PFT is not previously reported. No recurrence or metastatic disease has been reported after resection of PFTs elsewhere in the body, and this tumor seems to have a benign clinical course.

An approach to the classification of spindle cell proliferations in the urinary bladder

Spindle cell proliferations of the urinary bladder are uncommon but may cause significant diagnostic difficulty resulting from the degree of morphologic overlap between clinically benign and malignant lesions. These difficulties may be amplified in small biopsies because some of the more specific diagnostic features may not be present for evaluation. In addition, the number of different diagnostic terms applied to the same entity has added confusion to this diagnostic area. This review discusses the nomenclature, morphologic criteria, and immunohistochemical features used to classify spindle cell proliferations occurring in the urinary bladder, including those with myofibroblastic, smooth muscle, skeletal muscle, epithelial (sarcomatoid urothelial carcinoma), fibroblastic, and neural differentiation. A separate discussion of 5 challenging differential diagnostic scenarios is also presented.

ALK-1 expression in inflammatory myofibroblastic tumor of the urinary bladder

Inflammatory myofibroblastic tumor (IMT) of the bladder is an uncommon myofibroblastic spindle cell proliferation. Because of its cytologic features and infiltrative nature, it may be difficult to distinguish histologically from sarcomatous proliferations such as sarcomatoid urothelial carcinoma, leiomyosarcoma, and embryonal rhabdomyosarcoma. Recently, anaplastic lymphoma kinase (ALK) gene translocations or ALK protein expression in IMT has been reported, especially in patients of relatively young ages. However, there are only a few reports mentioning IMT of the bladder. We sought to determine the frequency of ALK expression among IMTs of the urinary bladder. We examined 16 cases of IMTof the bladder in 14 patients to elucidate the incidence of ALK-1 expression by immunohistochemistry and its diagnostic usefulness. The age of patients with IMT ranged from 18 to 76 years, with an average age of 42.8 years. The tumors from 10 of 14 patients (12 of 16 cases) were positive for ALK-1. ALK-1-positive cases ranged in age from 18 to 73 years (mean, 39.2 years; median, 38 years) and ALK-1-negative cases from 41 to 76 years (mean, 41.5 years; median, 44.5 years). Two locally recurrent cases were positive for ALK-1 in both the primary and recurrent lesion. ALK-1 immunostaining was detected only in the cytoplasm, with granular or subplasmalemmal linear features, suggesting ALK gene translocation. ALK-1 immunostaining was also performed in 8 sarcomatoid urothelial carcinomas, 5 genitourinary leiomyosarcomas, and 2 stromal tumors of uncertain malignant potential of the prostate, all of which were negative. These results support that ALK-1 immunostaining is useful to differentiate IMT from other malignant spindle cell neoplasms of the bladder. There were no histologic differences between ALK-1 positive and negative IMTs.

Lésions bénignes diverses de la vessie et de la voie excréto urinaire

Miscellaneous benign lesions of the bladder are composed of morphologic aspects of the urothelial mucosa. They are epithelial lesions (von Brunn nests, glandularis cystitis, nephrogenic adenoma, polypoid cystitis and epidermoid metaplasia), myofibroblastic proliferations and heterotopias (endometriosis, endocervicosis, endosalpingiosis and ectopic prostatic tissue). Etiology, morphologic aspects and differential diagnosis are discussed.

Pseudosarcomatous fibromyxoid tumor of the prostate

A very rare case of benign infravesical obstruction due to a pseudosarcomatous fibromyxoid tumor of the prostate is presented. This entity is clinically and histologically difficult to distinguish from a malignant lesion. A discussion of the histopathological features and a review of the literature is given.

Clinical presentation and outcome of high-grade urinary bladder leiomyosarcoma in adults

OBJECTIVES

To determine the clinical presentation and outcome of patients with high-grade bladder leiomyosarcoma.

METHODS

Between July 1986 and April 1998, 36 adult patients (mean follow-up 56 months) with a diagnosis of urinary bladder leiomyosarcoma were evaluated at the University of Texas M. D. Anderson Cancer Center. We retrospectively reviewed the records of these patients for information on clinical features, treatment, and outcome.

RESULTS

The mean age of the patients was 63 years. Twenty-six patients were white men in their seventh decade. The most common symptom at presentation was gross hematuria (81% of patients), followed by increased urinary frequency (28%), and dysuria (19%). Thirty-five patients were treated surgically for bladder leiomyosarcoma; of these, 12 (34%) developed recurrent disease (5 with local recurrence and 7 with distant metastasis), with a median time to diagnosis of recurrent disease of 8.3 months. The most common site of distant failure was the retroperitoneum. The disease-specific survival rate at 1, 3, and 5 years was 88.6%, 62.0%, and 62.0%, respectively. Multivariate analyses demonstrated that only the Memorial Sloan-Kettering Cancer Center disease stage system was a significant predictor of survival of patients with bladder leiomyosarcoma (P = 0.018).

CONCLUSIONS

In patients with high-grade leiomyosarcoma of the bladder, radical cystectomy in the face of localized disease, whether at the initial presentation or after neoadjuvant chemotherapy, can result in a 5-year, disease-specific survival rate of 62.0%.

[Pseudosarcomatous fibromyxoid tumor of the prostate: report of a case]

The authors report a case of pseudosarcomatous fibromyxoid tumor of the prostate. It is always a benign lesion, whose mains differentials diagnoses are sarcomas of the prostate. Diagnosis is based on histological examination. Treatment is surgical.

Inflammatory pseudotumor and sarcoma of urinary bladder: differential diagnosis and outcome in thirty-eight spindle cell neoplasms

We assessed diagnostic criteria among 38 spindle cell tumors of the urinary bladder and obtained follow-up in 36 patients. Patients comprised 28 males and 10 females aged 2.5 months to 87 years. Hematuria was the commonest presenting symptom (27 patients). After review and immunohistochemical workup, 17 patients had inflammatory pseudotumor (myofibroblastic tumor), 4 postoperative spindle cell nodule, 1 leiomyoma, 13 sarcoma (7 low-grade; 6 high-grade), and 3 carcinoma. Mean age was 38 years for pseudotumor (range 15 to 74), 65 for postoperative spindle cell nodule, 51 for sarcoma, and 76 for carcinoma. Size of pseudotumor averaged 4.4 +/- 0.7 cm (range 1.5 to 13.0), similar to sarcoma, 4.0 +/- 0.6 cm (range 0.5 to 7.0). Similar proportions of benign tumors and sarcomas had muscularis propria invasion. The criteria that best differentiated sarcoma from inflammatory pseudotumor were presence of necrosis at the tumor-detrusor muscle interface in muscle-invasive cases, and nuclear atypia. Sarcoma also had less prominent microvasculature, less variable cellularity, consistently > or =1 mitotic figure per 10 high-power fields, and predominant acute inflammation without plasma cells. p53 protein nuclear immunostaining was moderate, unlike the rare to absent staining in pseudotumors. Because all 12 sarcomas were desmin-negative, we did not call them leiomyosarcoma; they overlapped with benign tumor in epithelial, mesenchymal, and actin immunostaining. Among 12 sarcoma patients, 2 died of tumor (at 3 months). Two of four experienced tumor recurrence after partial cystectomy (2 and 26 months). No pseudotumors recurred after transurethral resection or partial cystectomy, although one patient, 5 months after transurethral resection, had histologically identical pseudotumor that the surgeon considered residual. Another patient with pseudotumor, not a candidate for tumor ablation after transurethral resection, had continued tumor growth and he died of urosepsis. In conclusion, inflammatory pseudotumor, although overlapping with sarcoma in presentation, age range, and size, does not metastasize and remains histologically distinct from low-grade sarcoma.

Pseudosarcomatous myofibroblastic tumor and myosarcoma of the urogenital tract

OBJECTIVE

Pseudosarcomatous myofibroblastic tumors (PMTs) of the urogenital tract are rare but distinctive lesions. Despite their benign behavior, they are frequently misinterpreted as leiomyosarcomas and rhabdomyosarcomas in preoperative biopsies and even in resected specimens because of their atypical spindle-cell features. Precise diagnosis of PMTs is important to avoid unnecessary radical therapy. We analyzed urogenital myoid tumors to clarify which of their characteristics are useful for the differential diagnosis.

METHODS

We evaluated 7 urogenital myoid tumors consisting of 3 PMTs, 2 leiomyosarcomas, and 2 rhabdomyosarcomas. We studied the expression of various immunohistochemical muscle-cell markers including desmin, muscle-specific actin, alpha-smooth muscle actin, high-molecular-weight caldesmon, and myogenin.

RESULTS

Desmin, muscle-specific actin, and alpha-smooth muscle actin were noted variably in all tumor types, whereas high-molecular-weight caldesmon was expressed only in leiomyosarcomas, and myogenin was expressed only in rhabdomyosarcomas.

CONCLUSION

High-molecular-weight caldesmon and myogenin are useful for differentiating urogenital PMTs from myosarcomas.

Neurofibroma of the bladder wall in von Recklinghausen's disease

Neurofibromatosis, or von Recklinghausen's disease, is an autosomal dominant disease with multiple neurofibroma and café-au-lait spots. However, neurofibroma in the bladder wall is a rare condition in von Recklinghausen's disease. A 31-year-old man with neurogenic voiding dysfunction due to sacral meningocele and acute urinary retention with neurofibroma of the bladder wall is presented with detailed radiologic evaluation. Patients with von Recklinghausen's disease should be carefully evaluated if urological symptoms exist.

Increase in expression of Hsp47 and collagen in hereditary gingival fibromatosis is modulated by stress and terminal procollagen N-propeptides

HGF is a rare oral condition characterized by a slow, progressive enlargement of the gingiva, involving both the maxilla and mandible. HGF provides a model for the study of regulatory features of conditions characterized by connective tissue hyperplasia. In this study, the culture characteristics of gingival fibroblasts derived from patients of the same family with HGF (n = 4) were similar with regard to cell cycle analysis. Flow cytometric DNA content analysis revealed uniform DNA diploidy for fibroblasts cultured from NG and HGF. NG cells showed a low S-phase fraction (19.8%) and G2/M fraction (5.8%) and a relatively high G1 phase fraction (74%). In contrast, HGF cells from all members of the tested kindred, exhibited diploid cells with a higher S-phase (40.9%) and G2/M (10.1%) fraction and a relatively low G1 phase fraction (40.9%). Furthermore, we demonstrated that the expression and production of Hsp47 parallels the increased levels of collagen secretion observed in HGF. In addition, we show that Hsp47 and collagen are coordinately regulated following stress via a feedback mechanism mediated by N-terminal procollagen propeptides. Utilizing confocal microscopy and antibodies directed against GST-fusion proteins encompassing the pro alpha1(I) N-propeptide globular domain (NP1) (residues 23-108), it was apparent that this regulatory mechanism does not involve significant interaction with Hsp47's chaperoning of procollagen.

Sarcomatoid carcinoma of the urinary bladder: a clinicopathologic and immunohistochemical analysis of 14 patients

Sarcomatoid carcinoma of the urinary bladder is a rare entity, in which both the histogenesis and biological behavior remain controversial. We herein describe the clinicopathologic and immunohistochemical profiles of sarcomatoid carcinomas and discuss the significance of cell adhesion molecules in the development of this peculiar neoplasm. The authors examined formalin-fixed and paraffin-embedded tissue samples from 14 patients with sarcomatoid carcinoma of the urinary bladder. An immunohistochemical analysis was performed by using antibodies against epithelial and mesenchymal antigens as well as adhesion molecules. Most patients suffered from an advanced stage of the tumor, extending to the muscular layer (7 cases) or to the perivesical tissues (5 cases). Microscopically, all 14 tumors were composed predominantly of a carcomatoid component and an obviously carcinomatous component. The sarcomatoid component was composed of a mixture of spindle cells, round cells, and pleomorphic giant cells. The carcinomatous components consisted of papillary or nonpapillary high-grade transitional cell carcinoma (TCC). The zones of gradual transition between the carcinomatous and the sarcomatous elements were focally apparent in each tumor. The findings of an immunohistochemical examination indicated that both carcinomatous and sarcomatoid components expressed epithelial antigens (pankeratin or EMA), even though the staining pattern varied from case to case. As for cell adhesion molecules, the carcinomatous components were positive for E-cadherin (8 of 12), CD44s (8 of 12), and CD44v6 (6 of 12). Although the sarcomatoid components were also positive for E-cadherin (5 of 12), CD44s (4 of 12), and CD44v6 (3 of 12), these rates were lower than those in the carcinomatous components. Six patients died of their disease between 5 and 36 months after the diagnosis was made. The recognition of sarcomatoid carcinomas has important therapeutic and prognostic implications. It seems appropriate to treat these neoplasms in the same manner as conventional high-grade TCCs with similar degrees of invasion. We consider that sarcomatoid carcinomas should be regarded as a high-grade carcinoma that shows a prominent pseudosarcomatous dedifferentiation. The sarcomatoid component of sarcomatoid carcinomas may result from either anaplastic changes or dedifferentiation related to the process of losing cell adhesion molecules.

Urinary bladder. Mimics of neoplasia and new pathologic entities

A wide range of epithelial and mesenchymal pseudoneoplastic disorders of the urinary bladder may clinically and pathologically mimic a malignant neoplasm. These lesions usually require a tissue biopsy for definitive diagnosis. It is important to be aware of these lesions and their spectrum of morphologic appearances to avoid overdiagnosis and inappropriate aggressive therapy.

Synovial sarcoma of the prostate with t(X;18)(p11.2;q11.2)

A case of monophasic synovial sarcoma of the prostate in a 37-year-old man is reported. Histologically, the tumor was chiefly composed of uniform spindle and oval cells, which often formed interlacing fascicles resembling those of fibrosarcoma. In some areas, the compact fascicles of tumor cells alternated with hypocellular myxoid tissue bearing a superficial resemblance to peripheral nerve sheath tumors, whereas small portions of the tumor showed a pericytomatous pattern consisting of polygonal cells arranged around dilated, thin-walled blood vessels. By immunohistochemistry, vimentin was detected in most cells, and a focal reactivity for epithelial membrane antigen was also observed. The tumor cells, however, were negative for keratin, S-100 protein, neuron-specific enolase, CD34, desmin, muscle-specific actin, and alpha-smooth muscle actin. Cytogenetic analysis and fluorescence in situ hybridization (FISH) using the cultured tumor cells demonstrated a translocation t(X;18)(p11.2;q11.2), an aberration specific for synovial sarcoma. To the authors' knowledge, this is the first report of a primary prostatic synovial sarcoma confirmed by cytogenetic analysis.

Carcinosarcoma and sarcomatoid carcinoma of the bladder: clinicopathological study of 41 cases

PURPOSE

Carcinosarcoma of the bladder is a rare neoplasm characterized by an intimate admixture of carcinoma and malignant soft tissue neoplasm. The clinical usefulness of separating carcinosarcoma (carcinoma with sarcomatous component) from sarcomatoid carcinoma (carcinoma with spindle cell carcinomatous component) is uncertain, and it comprises the subject of this report.

MATERIALS AND METHODS

We reviewed the clinical and pathological records of 10 men and 5 women a mean of 66 years old with carcinosarcoma, and 21 men and 5 women a mean of 66.5 years old with sarcomatoid carcinoma of the bladder, as documented in the files of the Mayo Clinic between 1936 and 1995.

RESULTS

Of the 15 patients in the carcinosarcoma group 9 had urothelial carcinoma, small cell carcinoma, 3 had squamous cell carcinoma and 2 had more than 1 type. The sarcomatous component included chondrosarcoma in 3 cases, leiomyosarcoma in 3, malignant fibrous histiocytoma in 3, osteosarcoma in 2, fibrosarcoma in 1, rhabdomyosarcoma in 1 and more than 1 type in 2. All disease was high stage at presentation. Treatment included cystectomy in 11 patients with (4) and without (7) radiation therapy, and transurethral resection in 4 with (1) and without (3) radiation therapy. Mean followup available in 14 cases was 34 months (range 1 to 144). A total of 11 patients died of cancer at 1 to 48 months (mean 17.2) and 2 survived for 8 to 131 months. Of the 26 patients in the sarcomatoid carcinoma group 18 had urothelial carcinoma, 1 had squamous carcinoma, 2 had urothelial carcinoma combined with squamous cell carcinoma and 5 had spindle cells only with no recognizable epithelium. All but 1 case was high stage at diagnosis. Treatment included transurethral resection in 17 patients with (7) and without (10) radiation therapy, including 1 who also received chemotherapy, and only cystectomy in 5, including 2 who also underwent radiation therapy and 1 who also received chemotherapy. Mean followup available in 21 cases was 49 months (range 1 to 420). A total of 17 patients died of cancer at 1 to 73 months (mean 9.8), 1 was alive at 140 months and 3 died of unrelated causes.

CONCLUSIONS

Carcinosarcoma and sarcomatoid carcinoma of the bladder are highly aggressive malignancies with a similar outcome regardless of histological findings and treatment. Pathological stage is the best predictor of survival.

Sarcomas and related proliferative lesions of specialized prostatic stroma: a clinicopathologic study of 22 cases

Sarcomas and related proliferative lesions of the specialized prostatic stroma have been the subject of case reports and, thus, have not been well characterized. We reviewed the clinicopathologic features of 22 cases and studied the immunohistochemical profile of 9. Patient age ranged from 25 to 86 years; mean age was 54 years, and peak incidence was in the 6th and 7th decades. The most common clinical presentation was urinary retention, then abnormal results of digital rectal examination, hematuria or hematospermia, and a palpable rectal mass. The cases were grouped into two categories: prostatic stromal proliferation of uncertain malignant potential (PSPUMP, 18 cases) and prostatic stromal sarcoma (PSS, 4 cases) based on the degree of stromal cellularity and the presence of mitotic figures, necrosis, and stromal overgrowth. Four histologic patterns of PSPUMP were identified: (1) hypercellular stroma with scattered cytologically atypical cells associated with benign glands, (2) hypercellular stroma with minimal cytological atypia associated with benign glands, (3) hypercellular stroma with or without cytologically atypical cells, associated with benign glands in a "leaflike" growth pattern that resembled phyllodes tumors of the mammary gland, and (4) hypercellular stroma without cytologically atypical stromal cells and without glands. Prostatic stromal sarcoma showed greater cellularity, mitoses, necrosis, and stromal overgrowth than PSPUMP and consisted either of stromal elements with benign glands in a pattern that resembled malignant phyllodes tumors of the mammary gland (3 cases) or of purely stromal elements (1 case). Positive immunohistochemical reactions were noted using vimentin in 9 of 9 cases, CD34 in 8 of 8, HHF-35 in 2 of 8, smooth muscle actin in 3 of 9, desmin in 4 of 8, S-100 protein in 0 of 9, estrogen receptor in 1 of 7, and progesterone receptor in 6 of 7. None of the cases classified as PSS were positive for HHF-35, smooth muscle actin, or desmin. Of the 13 patients classified as having PSPUMP who did not undergo definitive local therapy at the time of diagnosis, recurrent signs or symptoms were seen in six (46%), necessitating additional therapy. Distant metastases to lung and bone developed in one patient classified as having PSS. Clinical and pathologic findings in this patient suggested a progression from PSPUMP to PSS. We conclude that sarcomas and related proliferative lesions of the specialized prostatic stroma encompass a spectrum of histologic features and may be grouped into two clinicopathologic categories: PSPUMP and PSS. Based on their distinctive histologic appearance and immunohistochemical profile, PSPUMP and PSS can be differentiated from other mesenchymal lesions of the prostate.

Solitary fibrous tumor of urinary bladder: report of two cases

The clinical and pathologic features of two cases of solitary fibrous tumor arising from urinary bladder wall are described. To our knowledge, solitary fibrous tumors have not been previously reported at this site. Both tumors showed typical histologic features of solitary fibrous tumor, were CD34 immunostain positive and pursued a benign clinical course on short term follow-up.

Pseudosarcomatous fibromyxoid tumor of the bladder: biphasic contrast-enhanced helical CT findings

We report a case of pseudosarcomatous fibromyxoid tumor of the bladder in a 23-year-old man with a 2 month history of painless gross hematuria, which was studied by biphasic contrast-enhanced helical CT. CT demonstrated a 2 cm diameter polypoid enhancing mass in the anterior bladder wall. The lesion measured 103 and 91 HU on early and delayed images, respectively. Increased contrast enhancement was attributed to a histologically highly vascular myxoid stroma.