Solitary fibrous tumor of urinary bladder: report of two cases

Solitary fibrous tumor of the bladder: Diagnostic challenges and surgical management in an elderly male, a case report and literature review

INTRODUCTION

Solitary fibrous tumors (SFTs) of the bladder are rare mesenchymal neoplasms that mimic other bladder tumors, requiring a multidisciplinary approach for diagnosis and management.

CASE PRESENTATION

An 81-year-old male with a 30-pack-year smoking history presented with clotting hematuria and acute renal failure. Imaging revealed a large bladder mass causing bilateral ureteral obstruction. Transurethral resection and immunohistochemical analysis confirmed an SFT. The patient underwent cystoprostatectomy with Bricker diversion, achieving full recovery.

DISCUSSION

Bladder SFTs are often misdiagnosed as other spindle cell tumors. Histopathology and CD34 immunopositivity are key for diagnosis. Although typically benign, recurrence and metastasis require long-term follow-up.

CONCLUSION

This case underscores the rarity of bladder SFTs and highlights the importance of accurate diagnosis and complete surgical excision for optimal outcomes.

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.

Two Cases of Solitary Fibrous Tumor Involving Urinary Bladder and a Review of the Literature

Solitary fibrous tumor (SFT) is a rare neoplasia of mesenchymal origin, initially described in visceral pleura and lately discovered to have ubiquitous distribution. SFT of the urogenital tract is uncommon and appears to have similar morphologic features and biologic behaviors as SFTs found elsewhere. We present two new cases of SFT of the bladder and review 22 similar cases published in the literature. Due to the general indolent behavior of these lesions, a complete but organ sparing surgical excision should be considered when technically feasible. Therefore, proper identification and characterization of SFT through morphological and immunohistochemical criteria on biopsy specimens are mandatory in the differential diagnosis from other more aggressive spindle-cell tumors, thus avoiding unnecessary radical surgery.

Mesenchymal tumours of the bladder and prostate: an update

Mesenchymal tumours of the urinary bladder and prostate are infrequent neoplasms. The body of literature is growing with isolated case reports and short series, and the majority of cases are benign neoplasms. Other than stromal tumour of uncertain malignant potential and prostatic stromal sarcoma, both neoplasms derived from the specific prostatic stroma, the mesenchymal neoplasms in these locations are identical to their counterparts seen in other organs. However, the limited amount of tissue generated by biopsy and rarity of mesenchymal lesions in these sites create unique diagnostic difficulties, while correct classification of the neoplasm often bears significant impact on prognosis and therapeutic strategy. In this review we summarise the diagnostic features, focus on the differential diagnosis, and highlight the potential diagnostic pitfalls of mesenchymal tumours of the bladder and prostate.

A case of concomitant occurrence of solitary fibrous tumor and urothelial high-grade invasive carcinoma of the urinary bladder

Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm, most commonly arising from the pleura. It has also been recently described to occur in extrapleural sites. To our knowledge, only 16 cases of SFT have been reported in the urinary bladder to date. We report the clinicopathological features of a vesical SFT occurring in a 60-year-old man who presented a concomitant invasive high-grade urothelial cell carcinoma. No similar association has been found in the accessible literature. The morphologic and immunohistochemical clues leading to the correct diagnosis of SFT have been correlated with the data of the literature, and the differential diagnosis is briefly discussed.

Soft tissue tumors of the anorectum: rare, complex and misunderstood

Anorectal soft tissue tumors are uncommon and often present both diagnostic and therapeutic challenges. Although many of these tumors are identified with imaging performed for unrelated reasons, most present with nonspecific symptoms that can lead to a delay in diagnosis. Historically, radical surgery (abdominoperineal resection) has been the mainstay of treatment for both benign and malignant anorectal soft tissue tumors. However, a lack of proven benefit in benign disease along with changes in technology has called this practice into question. In addition, the role of radiation and/or chemotherapy remains controversial. In this manuscript, we review the history and current status of anorectal soft tissue tumor management, with a particular focus on challenges in optimizing survival.

[Solitary fibrous tumor of the urinary bladder: a case report]

Solitary fibrous tumor (SFT) is one of the mesenchymal tumor usually occurs in the pleura. Extrapleural occurrence of SFT is uncommon. We herein report an extremely rare case of 72-year old man with SFT originated in the urinary bladder. The tumor was incidentally discovered as a mass of 8.5 mm in diameter by a pelvic MRI. Cystoscopy revealed the protruding submucosal tumor in the center of the trigon. Transurethral resection was carried out. Pathological examination revealed a tumor composed of spindle cells with rich vascularity surrounded by abundant collagen fibers. The immunohistochemical findings showed a strong positivity to CD 34 and relatively weak positivity to Bcl-2. MIB-1 index indicated less than 3%, thus the tumor was diagnosed as a solitary fibrous tumor. The patient has no evidence of disease 16 months after the surgery. The current case was the first report in Japan and the twelfth worldwide.

Solitary fibrous tumor: is there a molecular relationship with cellular angiofibroma, spindle cell lipoma, and mammary-type myofibroblastoma?

Solitary fibrous tumor (SFT) is a mesenchymal tumor characterized by ovoid cells, branching blood vessels, stromal hyalinization, and CD34 immunoreactivity. Studies have shown loss of 13q in a group of morphologically similar entities, including cellular angiofibroma, mammary-type myofibroblastoma, and spindle cell lipoma. The histologic and immunophenotypic overlap between SFT and the latter group of tumors suggests that these tumors may be genetically linked. We tested a group of 40 SFTs to assess for loss of RB1 (13q14) by fluorescence in situ hybridization (FISH). All 38 SFTs with evaluable signals failed to show loss of RB1 (13q14) by FISH. All cases of cellular angiofibroma (1/1), spindle cell lipoma (6/6), and mammary-type myofibroblastoma (4/4), which were used as a control group, showed monoallelic or biallelic loss of RB1. The absence of RB1 loss in SFTs suggests that they are not related to cellular angiofibroma, mammary-type myofibroblastoma, or spindle cell lipoma.

Solitary fibrous tumor of the male pelvis: findings at CT with histopathologic correlation

We present CT imaging findings with pathologic correlation in a rare case of a solitary fibrous tumor arising in the pelvis in a 34-year-old man. This tumor presented as a hypervascular heterogeneously enhancing deep pelvic mass at CT. Although CT initially suggested the prostate as the site of origin for this tumor, no prostate involvement was found at surgery; CT accurately excluded bladder and rectal involvement.

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.

Solitary fibrous tumor (SFT) of the pelvis

Solitary fibrous tumors (SFTs) are well recognized in the pleura, but their occurrence at other sites has only become appreciated in recent years, as a consequence of which extrapleural examples often go unrecognized and misdiagnosed. Because of their rarity, overall experience concerning this tumor has not been significant and reports detailing radiological findings are few. We herein report an unusual case of a large retroperitoneal pelvic SFT with features of high vascularity negating successful surgical resection.

Primary myxoid solitary fibrous tumor involving the seminal vesicle

Although focal myxoid change is a well-recognized feature of solitary fibrous tumor (SFT), predominantly myxoid SFT are exceedingly rare. Reported herein is the case of a 65-year-old man with SFT containing abundant myxoid matrix, arising from the capsule of the right seminal vesicle. To the authors' knowledge this is the first myxoid SFT involving the male genito-urinary system. Recognition of the myxoid variant of SFT is crucial, given possible confusion with a variety of myxoid spindle cell neoplasms with different biological potential in the pelvic cavity.

Solitary fibrous tumor in bladder wall

The solitary fibrous tumor is a rare mesenchymal tumor, occurring preferentially in pleura, which has recently been described in extrathoracic sites. There are 6 reports on primary solitary fibrous tumor of bladder. They affect preferably men with mean age around 57 years, are usually asymptomatic and, despite eventually presenting morphologic features of malignancy, tumor resection is considered curative. We report the seventh case of solitary fibrous tumor in bladder wall, discussing differential diagnoses, and call the attention to this rarely occurring entity, which has benign behavior and should be managed conservatively.

[Solitary fibrous tumor. Two additional cases with urologic implications]

Solitary fibrous tumour is a well defined pathological entity originally described as a tumour of the pleura, but the occurrence of this neoplasm has increasingly been described at other sites. At present the development of these tumours is recognized as possible in virtually all anatomical sites. The rarity of this type of pathology has not allowed up to the present time clarification of the histogenesis, clinical behaviour, treatment and prognosis of these tumours. Differential diagnosis becomes important, especially in extra-thoracic sites so as not to mistake them for much more aggressive mesenquimal tumours. Two additional cases of this neoplasm are presented, one of them responsible for obstructive uropathy, accidentally found in a patient suffering renal trauma. The second tumour was located in the spermatic cord. A review of the theme is presented based on the available literature.

Solitary fibrous tumor of the lower urogenital tract: a report of five cases involving the seminal vesicles, urinary bladder, and prostate

Solitary fibrous tumor (SFT) is not as site-restricted as once believed. Initially described as a tumor of the pleura, SFT is now recognized at various extrathoracic sites. We report 5 cases of extrapleural SFT involving the male lower urogenital tract. The tumors involved the seminal vesicles (2 cases), urinary bladder (2 cases), and the prostate (1 case). The patients with bladder tumors were asymptomatic. The patients with seminal vesicle involvement presented with hematuria or groin pain. The patient with prostate involvement presented with urinary retention. The prostate tumor was large, and it could not be completely excised because of its extensive spread beyond the prostate into the pelvis. The other 4 tumors were completely excised, and none has recurred during limited follow-up. By histological criteria, 4 of the tumors were benign, and 1 was malignant. Even though the classic histological features of SFT were well developed in each case, all 5 tumors were initially misdiagnosed, including 3 benign tumors that were misclassified as sarcomas. These 5 cases confirm the male lower genitourinary tract as yet another site of origin for SFTs, challenge the notion that extrapleural SFTs invariably are benign, and draw attention to the problem of recognizing SFTs when they arise in unexpected sites.