A rare case of solitary fibrous tumour of the bladder

Abstract

Cite as: Can Urol Assoc J 2014;8(7-8):e552-3. http://dx.doi.org/10.5489/cuaj.1857 Published online August 11, 2014. AbstractSolitary fibrous tumour of the bladder is a rare mesenchymal neoplasm with a favourable prognosis. Its symptoms are usually secondary to obstructive symptoms rather than hematuria or other findings typical of other bladder neoplasms. We describe a case of solitary fibrous tumour of the bladder and review the literature. Case reportA 78-year-old man came to the emergency department because of hematuria and acute urinary retention. A cystoscopy revealed a solitary lesion at the bladder neck. A transurethral resection of the bladder tumour (TURBT) was performed. Pathologic analysis revealed a solitary fibrous tumour of the bladder without atypia. Immunohistochemistry showed positivity to CD34, Bcl-2, CD99 and vimentin and negativity for cytokeratins and S-100 protein. Five months after the first TURBT, the patient returned with recurrence and a repeat TURBT was performed. Pathological exam again revealed a solitary fibrous tumour. The patient is alive at 36 months, after the second TURBT. DiscussionSolitary fibrous tumour (SFT) of the bladder is a rare mesenchymal neoplasm. It is classified into 2 forms: pleural and extrapleural.1 It should not be confused with mesothelioma which is a tumour derived from the mesothelium. SFT is a mesenchymal tumour with a fibroblastic differentiation. 2 It was first described by Klemperer and Rabin in 1931, 3 but the first case in the urinary tract was reported in 1997. 4 About 15 cases of SFT of the bladder have been described in the literature. This type of tumour is usually asymptomatic and presents as a slow-growing well-delineated exophytic mass; therefore, obstructive symptoms are the most common. Furthermore, it can be source of paraneoplastic syndromes, like hypoglycemia secondary to insulin-like growth factor. 1,4 In our patient, the presentation was typical of any bladder neoplasm.The pathological analysis renders a proliferation of bland-looking spindly to oval epithelioid cells that form fascicles, between collagen bundles, and a prominent vasculature simulating an hemangiopericytoma (Fig. 1a). 1,4 Malignant counterparts are usually hypercellular lesions, cytologic atypia, necrosis and higher frequency of mitoses. 1Immunohistochemistry shows positivity to Bcl-2, CD34 (90-95%), CD99 (70%) and vimentin. It is probable that Bcl-2 is more sensitive than CD34 for the diagnosis (Fig. 1b). 4 Negativity for cytokeratin AE1/AE3, CD31 and S-100 protein is common. 1,4 In our case, the pathology report yielded positivity to CD34, bcl-2, CD99 and vimentin which strongly suggested a SFT. It was negative for muscle markers, cytokeratin, S-100 protein and anaplastic lymphoma kinase (ALK), which exclude other tumours, such as sarcomas with muscle differentiation, sarcomatoid carcinomas and neurofibromas.The differential diagnosis should be made with hemangiopericytoma, leiomyoma, nodular fasciitis, inflammatory myofibroblastic tumour, fibromatosis and benign ...

Solitary fibrous tumor of the urinary bladder: An unusual case report with literature review

“…The factors associated with increased likelihood of malignancy include infiltrative borders with regions of necrosis, high mitotic count, tumor size >10 cm, and poor histology [5] . Additionally, it can cause paraneoplastic syndromes, like hypoglycemia secondary to insulin like growth factor [6] . Risk stratification into low, intermediate or high risk of metastasis is done based on scoring systems that account for age at diagnosis, tumor size, mitotic count and tumor necrosis.…”

“…It is slow growing polypoid intraluminal or submucosal mass with or without extension into the perivisceral fat. Histologically under light microscope, mesenchymal neoplasms are composed of predominantly fibrous lesions containing proliferation of fusiform tumor cells (spindle shaped tumor cells) with large collagenized areas alternately distributed between the dense region (less collagen), and the loose region (abundant collagen), and hyalinized vessels [6] . One of the most common patterns consists of alternating hyper and hypocellular areas with a hemangiopericytoma like appearance [9] .…”

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

“…The diagnosis depends on histological and immunohistochemical examinations. The pathological analysis features proliferation of bland-looking spindle to oval epithelioid cells that form fascicles between collagen bundles with a prominent vasculature simulating hemangiopericytoma [ 29 ]. Hemangiopericytoma and SFT form a histologic spectrum of fibroblastic-type mesenchymal neoplasms with overlapping clinical, imaging, and cytopathologic features.…”

A small solitary fibrous tumor of the bladder

“…In the English literature 15 cases have been reported, [6,[8][9][10][11] all with symptoms related to tumor volume (up to 12 cm in diameter), and presence of radiologic findings. [12][13][14][15][16] Sometimes, a diagnosis of malignant soft tissue tumor was considered. Actual malignant bladder SFT has been described, [7] while to the best of our knowledge, this is the first case of a SFT of just 4 mm.…”