Hindawi Publishing Corporation Case Reports in Urology Volume 2016, Article ID 5145789, 5 pages http://dx.doi.org/10.1155/2016/5145789 Case Report Two Cases of Solitary Fibrous Tumor Involving Urinary Bladder and a Review of the Literature Eduardo Yukio Tanaka,1,2 Vitor Bonadia Buonfiglio,1,2 Joao Padua Manzano,1,2 Renée Zon Filippi,2 and Marcus Vinicius Sadi1,2 1 Federal University of Sao˜ Paulo, Sao˜ Paulo, SP, Brazil 2Hospital Israelita Albert Einstein, Sao˜ Paulo, SP, Brazil Correspondence should be addressed to Eduardo Yukio Tanaka; du [email protected] Received 12 June 2016; Revised 5 September 2016; Accepted 8 September 2016 Academic Editor: Fumitaka Koga Copyright © 2016 Eduardo Yukio Tanaka et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 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. 1. Introduction Computed tomography (CT) revealed a well-delineated and homogeneous retrovesical solid mass that measured 5× Solitary fibrous tumor (SFT) is a rare neoplasia of mesenchy- 3 cm in diameter (Figure 1). mal origin, initially described in visceral pleura and lately foundtohaveubiquitousdistribution[1].Mosttumorsare Magnetic resonance imaging (MRI) confirmed the pres- benign and, contrary to previous beliefs, they do not derive ence of this noninfiltrative solid tumor, between the rectum from the mesothelium but rather from dendritic interstitial and the bladder with a thin capsule of low signal in T2. cells, which express CD34 and have generalized distribution A transrectal ultrasound needle guided biopsy was per- in tissues, a feature that helps to recognize them in other formed with a presumptive diagnosis of a pelvic sarcoma. The organs [2, 3]. histology showed spindle-cell-shaped proliferation express- The urogenital tract involvement is very rare. We present ing CD34 antigen and vimentin. Immunochemistry was two cases of SFT of the bladder and review 22 cases published positive for Bcl-2 favoring the diagnosis of SFT. in the literature to date. Additional staging examinations, including chest X-ray andbonescan,didnotrevealmetastases.Colonoscopyshows 2. Case Report 1 no alteration. Extirpative surgery through an infraumbilical midline During a routine abdominal ultrasound examination, a incision was scheduled. The bladder and rectum could be well bulging of bladder floor with discrete left ureteral dilatation separated from the tumor and both organs were spared. The wasdetectedinanasymptomatic60-year-oldman.The pathology report described an 8,0 × 6,0 tumor weighting 101 patient’s medical history was unremarkable. Clinical exam- grams, with a regular surface and negative surgical margins. 3 ination revealed an enlarged prostate of 40 cm .Acomplete His postoperative recovery was uneventful. biochemical workup evaluation was normal and his PSA level Immunohistochemistry demonstrated expression of was 2.1 ng/mL. CD34 (Figure 3), Ki-67 (Figure 4), and STAT6 (Figure 5) but 2 Case Reports in Urology Figure 1: Magnetic resonance imaging T2-weighted imaging showed a mass of 5 cm in diameter on the posterior wall of the bladder. Figure 3: Immunohistochemistry of CD34. (pT2a) and a well-circumscribed mass measuring 4,0 cm × 4,0 cm. The diagnosis of a bladder SFT was rendered based on the histopathologic and immunohistochemical findings consisting of short-spindled cells with meager amounts of eosinophilic cytoplasm without necrosis. The tumor cells were immunoreactive to CD34, CD99, c-kit, and Bcl-2 and they were negative for CD117 (c-kit), anaplastic lymphoma kinase(ALK-1),smoothmuscleactin,desmin,cytokeratin, and S100 protein. Mitotic activity was <1mitosisper10HPFs. Figure 2: Hematoxylin and eosin stained section shows spindle- After 10 years of follow-up, his PSA is undetectable and there shaped cells. are no signs of the SFT recurrence in the bladder. 4. Discussion no expression of ALK, EMA, S100, 1A4, HHF 35, CD117, and CD99. The tumor consisted of irregularly dispersed cells in Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm a so-called patternless. The cells were rounded and spindle- that accounts for less than 2% of all soft-tissue tumors shaped with little pleomorphism and few vesicular nuclei usually involving the pleura, pericardium, and peritoneum. and were intermingled with thick collagen fiber bundles. Klemperer and Rabin reported the first five cases of primary In parts, cystic degenerative changes and vascular and SFT in 1931 [23]. For a long time, SFTs were described as pseudovascular formations with broad rims of hyalinized “benign fibrous mesotheliomas” of the pleural cavity and collagen were observed (Figure 2). No reactivity was detected these tumors were erroneously thought to be exclusively using a CD117 (c-kit) antibody, consistent with the diagnosis confined to the serosal surfaces, due to an assumed mesothe- of a SFT. The proliferation index (Ki-67) was less than 2% lial origin [24]. It is now well established that SFTs are (Figure 4) suggesting a probable benign biologic behavior. ubiquitous neoplasms with both pleural and extrapleural Two years after surgery, the patient is well with no signs of distribution [25–28]. These tumors have been reported to tumor recurrence. arise from many organs including orbit, meninges, paranasal sinuses and upper respiratory tract, thyroid, sublingual gland, 3. Case Report 2 lung, mediastinum, pericardium, gastrointestinal tract, liver, kidney, peritoneum, adrenal gland, spinal cord, ovary, uterine A 60-year-old man with a rising PSA of 4,9 ng/mL was cervix/vagina, bladder, prostate, scrotum, testicular tunica found to have a perivesical mass in the left side of bladder vaginalis, skin, soft tissue, and periosteum. The first case on transrectal ultrasound (US). An US guided biopsy of involving the urinary tract was reported in 1997 [2]. the prostate and bladder was performed simultaneously. The SFT occurs equally in both sexes and the age of pre- histopathology showed a prostate acinar adenocarcinoma sentation varies from the second to sixth decade. Clinically Gleason Score 7(3 + 4) and a bladder hemangiopericytoma. it is a slow-growing, painless, well-delineated exophytic The patient underwent a nerve-sparing retropubic radical mass. Fewer than 5% of SFT presents with paraneoplastic and partial cystectomy to remove the perivesical bladder syndromes such as hypoglycemia secondary to insulin-like lesionduringthesamesurgicalprocedure.Recoverywas growthfactor[2].Inourreviewof22casesofSFTofthe uneventful and the patient was discharged on the 3rd post- urinary bladder previously described in the English literature operative day. (Table 1), 36% of the patients had voiding difficulty, 32% The final pathology report showed prostate acinar ade- had hematuria, 18% had incidental imaging finding, and 14% nocarcinoma with Gleason Score 7(3 + 4) of the right lobe presented with lower abdominal discomfort. Case Reports in Urology 3 Table 1: Reported 24 cases of SFT originating in urinary bladder. ´ andez [2] 59 M Voiding difficulty Excision3.5 24 Authors Age (years) Sex Symptoms Tumor size (cm) Treatment Follow-up (months) ın and Fern ´ 1617 Bruzzone et al.18 [16]19 Pata et al.20 [17] Wang et al. [18]21 Cheng et al. 74 [19]22 Seike et al. [20]23 Otta et Spairani al. et M [21]24 al. [22] 76 72 Chills, 67 diaphoresis, and acute abdominal Our pain case with hematuria M 41 Our M case 60 M 78 F M 10 M Low abdominal 60 pain, acute urine retention 60 M M Incidental MRI finding Low abdominal pain Incidental TC finding 17 Voiding difficulty Hematuria Incidental US finding Excision Incidental US finding 0.85 Wide excision, bladder 16 preservation 5.2 Partial cystectomy and segmental resection NA of the intestine Transurethral resection NA 60 18 Transurethral resection Partial 4 cystectomy and radical Wide 8 prostatectomy excision, Partial 9 bladder cystectomy preservation Transurethral resection 16 120 3 24 36 11 12 Bainbridge3 et al. [4] Bainbridge et4 al. [4]5 Westra et al. [5]6 Westra et 50 al. [5]7 42 Corti et8 al. [6] Lam9 et al. F [7] Huang et al. 67 [8]10 M Kim 6711 et al. [9] Leite Ishikawa et et al.12 al. [10] [11] M Tsurukawa 50 et al. [12]13 M Voiding 44 Heinzelbecker difficulty: et 7014 Tzelepi incidental et al.cystoscopy al. [14]finding [13] during M15 Mart 56 64 61 Incidental M Wang Increase 60 et MRI in M al. finding urinary (prostate [15] frequencycancer 24 surveillance) M M 59 M M Pelvic pressure F Recurrent Pelvic hypoglycemic pain, attack dysuria, and and lower urinary abdominal bleeding discomfort 50 F Urinary frequency, Incidental urgency, MRI tenesmus finding (prostatecancer screening) M Painless 15 gross hematuria