Abscess formation in the prevesical space and bilateral thigh muscles secondary to osteomyelitis of the pubis--basis of the anatomy between the prevesical space and femoral sheath

A 65-year-old man presented with abscess formation in the prevesical space and bilateral adductor muscles secondary to pubic osteomyelitis which was resolved by means of percutaneous drainage of the prevesical abscess. The pathway of abscess propagation can be explained on the basis of the anatomy between the prevesical space and femoral sheath.     

Solitary Fibrous Tumour of Thyroid: Report of Two Cases with Immunohistochemical Features and Literature Review

Solitary fibrous tumour (SFT) is a rare tumour principally found in adults in the pleural cavity. Extrapleural occurrences are rare. Two cases of SFT of the thyroid gland are described in this paper showing their distinctive microscopical architecture, namely “patternless growth pattern”. It is characterized by a bland spindle-cell proliferation alternating hyper- and hypo-cellular areas, keloid-like hyalinization and a focal hemangiopericytoma-like vascular pattern. Tumour cells revealed a diffuse strong positivity for CD34, CD99, bcl-2 and Vimentin, but negativity for Desmin, EMA, AE1/AE3, SMA, S-100 and CD31 antibodies. The differential diagnosis of thyroid SFT includes different types of spindle cell proliferation, benign and malignant mesenchymal tumours, medullary thyroid carcinoma, fasciitis-like papillary carcinoma, and undifferentiated (anaplastic) carcinoma. However, the morphologic and immunohistochemical findings of SFT are so characteristic that this diagnosis seldom represent a difficulty.     

Solitary fibrous tumor of renal pelvis

A 70-year-old Japanese man was referred because of a right renal mass of 2 years in duration. Imaging studies, including magnetic resonance imaging, revealed an ovoid mass, with relatively abundant vascularity, in the right renal pelvis. Right radical nephrectomy was done and a tumor measuring 6.0 x 4.5 x 4.0 cm was found in the renal pelvis. Solitary fibrous tumor (SFT) was highly suspected by histology. Immunohistochemical study using a monoclonal antibody directed against the human hematopoietic progenitor cell antigen (CD34) stain confirmed SFT. This is the first case of SFT of the renal pelvis. Although SFT is extremely rare in urogenital organs, this tumor must be included in the differential diagnosis when we encounter urogenital tumors consisting of mesenchymal elements.     

A locally aggressive solitary fibrous tumor of the leg: Case report and literature review

INTRODUCTIONThe solitary fibrous tumor (SFT) is a rare soft tissue tumor with a substantially benign clinical behavior. However, malignant neoplasms with local recurrence or distant metastases have been reported.PRESENTATION OF THE CASEThe authors present a case of an aggressive SFT of the leg, in a 55 years old Caucasian man. Radiological, histological and molecular findings are reported. The differential diagnosis, therapy and outcome of this rare tumor are also discussed.DISCUSSIONAn extensive review of literature showed SFT's clinical behavior as substantially benign, anyway aggressive or malignant neoplasms have been described. The potential risk of local recurrence and distant metastasis thus suggests wide surgical resection and careful long-term follow-up. Differential diagnosis may be quite laborious as SFT can mimic a variety of benign and malignant mesenchymal tumors; immunohistochemical analysis for CD34, CD99, vimentin and bcl-2 is then mandatory.CONCLUSIONOur clinical experience confirmed that SFT may have an aggressive behavior, however, conservative surgical treatment may be successful in the long term.     

Solitary fibrous tumor of the pelvis: an uncommon soft-tissue tumor. A case report

A rare case of Solitary fibrous tumor (SFT) of the pelvis is reported. A 76-years-old man presented with a low abdominal pain, acute urine retention and constipation. Imaging studies (US, CT MR) showed an 17 x 10 x 9 ovoid mass in the pelvis, dislocating bladder and rectum. Finally, trans-rectal needle biopsy suggested the diagnosis of SFT. En bloc excision of tumor and rectum (because of strong adhesions) was performed. Histological examination showed spindle and fibroblastic-like cells dispersed in collagenous areas with positive stains for CD34, bcl-2, CD99 and it confirmed diagnosis of SFT. No postoperative complications occurred, only vesico-sphincter dyssynergia was found by urodynamics. After 5 years, patient is disease-free. SFT is, usually, benign tumor with slow growth and excellent prognosis. Complete surgical resection is the only curative treatment. However, 10-15% of SFT are malignant and histological findings cannot always predict clinical behaviour. For this reason, careful and long term follow-up is necessary after surgery.     

Solitary fibrous tumor of the liver with CD 34 positivity and hypoglycemia

We report a new case of solitary fibrous tumor (SFT) of the liver, an extremely rare neoplasm. Including the present case no more than ten cases are reported in the English-language literature. To date there is no definite proof of the origin of this tumor. Both mesothelial and fibroblas-tic genesis has been postulated. The monoclonal antibody CD 34 has recently been used for the characterization of SFT. SFT would appear to be histogenetically related to a CD 34 — positive fibroblastic stem cell. A 61-year-old woman was admitted to our department with epigastric and right hypochondriac pain, weight loss, and hypoglycemia. Ultrasonography and computed tomography demonstrated a large heterogeneous mass in the right hepatic lobe. A right hepatectomy was performed. The tumor weighed 2850 g and microscopic section revealed a peculiar random pattern, the so-called patternless pattern of spindle tumor cells separated by abundant thick collagen bands. The tumor presented a number of highly cellular areas composed of plump spindle cell with hyperchromatic nuclei and rare mitotic figures. Ninety percent of the neoplastic cells displayed strong immunoreactivity for CD 34/My 10. The postoperative course was uneventful and the patient is alive and well without recurrence 6 years after surgery. Received for publication on June 16, 1997; accepted on Oct. 27, 1997     

Solitary fibrous tumor of the thoracic spinal cord

A 63-year-old woman presented with a rare case of primary solitary fibrous tumor (SFT) occurring in the extramedullary thoracic spinal cord. T1-weighted magnetic resonance (MR) imaging showed the tumor as a mildly hypointense area with homogeneous enhancement by gadolinium. T2-weighted MR imaging showed a hypointense mass with peritumoral edema. The tumor arose from one of the posterior spinal roots, with no attachment to the dura. The tumor was clearly circumscribed from the surrounding cord tissue and easily removed. Histological examination showed the tumor predominantly consisted of spindle cells separated by abundant collagen matrix fibers. Tumor cells were strongly positive for vimentin and CD34, but negative for glial fibrillary acidic protein, S-100 protein, epithelial membrane antigen, myelin basic protein, and keratin. SFT should be considered in the differential diagnosis of spindle cell central nervous system neoplasms, although SFT is extremely rare in the spinal cord.     

Solitary fibrous tumor of the adrenal gland with renal cell carcinoma and angiomyolipoma at the same time; a case report

Solitary fibrous tumor (SFT) is a neoplasm of pleura and its occurrence in the retroperitoneal space is rare. We report a case of SFT of the adrenal gland associated with ipsilateral renal cell carcinoma (RCC) and angiomyolipoma (AML). A 48-year-old woman was referred to our hospital for a left renal AML. Computed tomography (CT) in our hospital showed a left adrenal mass (25 x 20 mm). Because the adrenal tumor was nonfunctioning, she was followed at outpatient clinic. Four years later, CT showed an increase in the left adrenal tumor size (42 x 30 mm) and a left RCC. Left adrenectomy and partial nephrectomy for RCC and AML were simultaneously performed. Histological examination revealed adrenal SFT and clear cell carcinoma and AML of the kidney. We present a brief review on histological characteristics of retroperitoneal SFT and its occurrence in the adrenal grand region.     

肾孤立性纤维性肿瘤的影像学及病理学特征（附1例报告并文献复习）

目的：探讨肾孤立性纤维性肿瘤的影像学特征、病理学特征。方法：对1例直径1cm肾孤立性纤维性肿瘤患者术前进行彩色超声、CT及MRI检查,术后进行病理学观察及免疫组化标记,并结合相关文献进行分析。结果：影像学检查提示为肾实质性肿瘤。术后病理检查显示梭形肿瘤细胞排列无明显特征,但含有较丰富的薄壁血管和灶性胶原纤维束;瘤细胞表现温和,界限不清晰,胞质红染,核仁不明显,核分裂象少见,免疫组织化学检查：CD34、vimentin、bcl-2、CD99、CD10均阳性,CD31、SMA、desmin、S-100、PCK、EMA、CD21、CD23均阴性,Ki-67增殖指数为5％。结论：原发性肾孤立性纤维性肿瘤临床十分罕见,小肿瘤的影像学表现可能有某些特征,但仍需要病理学检查确诊。     

Solitary Fibrous Tumor in the Retroperitoneal Space: Report of a Case

Solitary fibrous tumors (SFTs) are spindle-cell neoplasms originally described in the pleura. It is now known that these tumors can develop in many sites. This report describes the case of a well-circumscribed tumor located around the superior mesenteric artery (SMA), which was initially thought to be either a superior SMA aneurysm, a lymphoma, or a neurogenic tumor. Histological examination demonstrated the tumor to be composed of a cellular proliferation of ovoid to spindle cells with a fine collagenous matrix in the short fascicles. Immunohistochemical staining was strongly positive for CD34 and negative for factor VIII, cytokeratin, desmin, and muscle-specific actin (HHF-35). These findings suggested a diagnosis of SFT in the retroperitoneal space. To our knowledge, this is the first report of an SFT located around the SMA. Based on the above findings, it is important to include SFT in the differential diagnosis of retroperitoneal tumors located around the SMA. Received: August 13, 2001 / Accepted: March 5, 2002 Reprint requests to: M. Kume     

肾脏孤立性纤维瘤临床、影像学及病理诊断(附2例报告及文献复习)

目的:探讨肾孤立性纤维瘤的临床、影像学及病理特征,并进行诊断和鉴别诊断,提高对该肿瘤的诊断水平。方法:对2例肾孤立性纤维瘤进行临床症状,影像学资料以及病理分析,并结合文献讨论。结果:2例肿瘤均位于左肾,1例来源于肾实质,1例与左肾盂关系密切,临床、影像学诊断为左肾癌,均行左肾根治性切除术,肿瘤大体为球形或表面略分叶状的包块,边界清楚,包膜完整。镜下梭形细胞呈束状、旋涡状或不规则状排列,部分与胶原纤维混杂,部分呈血管外皮瘤样结构。细胞无明显异型,核分裂象未见。免疫组化示肿瘤细胞CD34及CD99阳性,S100,SMA,CKpan,P63,HMB45均为阴性,确诊为肾脏孤立性纤维瘤,2例均随访6个月无复发转移。结论:肾孤立性纤维瘤是一种少见的肾脏肿瘤,临床及影像学上易误诊为肾癌或肾盂癌,免疫组化CD34阳性表达是其病理学特征性表现,根治性切除及术后长期随访是治疗肿瘤的必要手段。     

Recurrent intracranial solitary fibrous tumor with cerebrospinal fluid dissemination. Case report

Solitary fibrous tumor (SFT) is a benign and rare neoplasm. To date, only 37 patients with intracranial SFTs have been reported. Although a number of the tumors were recurrent and some later underwent malignant transformation, none of these lesions progressed to cerebrospinal fluid (CSF) dissemination. In this paper the authors report a case of SFT in which the lesion recurred several times and ultimately was disseminated by the CSF. The patient was a 63-year-old woman with multiple intracranial and spinal tumors. Fifteen years before this presentation, at the age of 48 she had been hospitalized for resection of a falcotentorial tumor. During the ensuing 15 years she underwent multiple surgeries and sessions of radiation therapy for recurrent lesions. The exclusive location of her tumors in the subarachnoid space at the end of this 15-year period indicate CSF dissemination of the tumor. The tumor that was resected when the patient was 48 years old and the latest resected lesion were analyzed by performing immunohistological CD34, epithelial membrane antigen, vimentin, S100 protein, and reticulin staining, and determining the MIB-1 labeling index (LI). Most of the results were identical, and both tumors were diagnosed as SFT according to a staining pattern that showed a strong and diffuse positive reaction for CD34. Nevertheless, the authors noted that the MIB-1 LI increased from less than 1% in the original tumor to 13% in the latest tumor. The increased proliferation of MIB-1 indicates that the malignant transformation could have occurred during tumor recurrence with CSF dissemination.     

Intracranial anaplastic solitary fibrous tumor/hemangiopericytoma: immunohistochemical markers for definitive diagnosis

Intracranial anaplastic hemangiopericytoma (AHPC) is a rare and malignant subset of solitary fibrous tumor/hemangiopericytoma (SFT/HPC) as per the WHO 2016 Classification of Tumors of the Central Nervous System. AHPC portends a poor prognosis and is associated with higher rates of recurrence/metastasis in comparison with SFT/HPC. Accordingly, it is critical to continue to define the clinical course of patients with AHPC and in so doing further refine clinicopathologic/immunohistochemical (IHC) criteria needed for definitive diagnosis. Herein, we describe clinical/histological characteristics of six patients with AHPC. In addition, we reviewed and analyzed the expression of various IHC markers reported within the literature (i.e., a total of 354 intracranial SFT/HPCs and 460 meningiomas). Histologically, tumors from our six patients were characterized by a staghorn-like vascular pattern, mitotic cells, and strong nuclear atypia. Immunohistochemically, all tumors displayed positive nuclear staining for STAT6; other markers, including CD34 and Bcl-2, were expressed only in three patients. Analysis of IHC expression patterns for SFT/HPC and meningioma within the literature revealed that nuclear expression of STAT6 had the highest specificity (100%) for SFT/HPC, followed by ALDH1 (97.2%) and CD34 (93.6%). Of note, SSTR2A (95.2%) and EMA (85%) displayed a high specificity for meningioma. Anaplastic SFT/HPC is a tumor with poor prognosis that is associated with higher rates of recurrence and metastasis in comparison with SFT/HPC. Given that anaplastic SFT/HPC requires more aggressive treatment than meningioma despite of a similar presentation on imaging, it is crucial to be able to distinguish between these tumors.

     

Solitary fibrous tumors arising in abdominal wall hernia sacs.

Solitary fibrous tumor (SFT) of the peritoneum is an unusual spindle-cell neoplasm. SFT was originally described in the pleura; however it is now diagnosed in multiple extrathoracic sites. Most believe that the tumor is of mesenchymal origin and should be classified as a variant of fibroma. SFT of the pleura and peritoneum have also been called fibrous mesothelioma, and the cell of origin is felt to be a pluripotential submesothelial mesenchymal cell. Primary tumors arising in hernia sacs are rare, and we report on two patients with hernia SFT. The first is a 67-year-old man who had a diffusely thickened distal left inguinal hernia sac. Within the sac was copious myxoid material mimicking pseudomyxoma peritonei. Herniorrhaphy and orchiectomy were performed. The second is a 44-year-old woman with a midepigastric mass attached to a ventral hernia. Wide local excision was performed. Both tumors demonstrated plump spindle cells, one with myxoid background and the other with keloidal collagen. Calretinin immunostaining was positive in both tumors, whereas CD34 was negative. This suggests tumor origin from a submesothial pluripotential cell that maintains potential for mesothelial differentiation. Surgical excision is the treatment of choice with the degree of resectability being a powerful predictor of outcome.     

Solitary fibrous tumor of central nervous system masquerading as meninigioma: Report of a rare case

IntroductionSolitary fibrous tumor (SFT) is a rare neoplasm of mesenchymal origin that occurs most often in the visceral pleura. It rarely occurs in the central nervous system (CNS). If they occur intracranially, they are extra-axially located and develop from the meninges.Case ReportHerein, we present a case of SFT in a 45 years old female. MR imaging showed isointense to hypointense signal intensity, and marked enhancement. Microscopically, the tumors showed characteristic “patternless-pattern” architecture. Elongated tumor cells formed fascicles alternating with hypocellular densely collagenous stroma. Immunohistochemistry for STAT6, CD34, BCL2 and CD99 favours the definitive diagnosis of SFT.ConclusionIn general, complete surgical resection may offer the best chance of a favourable clinical outcome. Their biological features remain largely unknown. Hence, the clinical management and prognosis is often challenging due to the lack of comprehensive data.     

Solitary fibrous tumor of the meninges in the posterior cranial fossa: magnetic resonance imaging and histological correlation--case report

A 58-year-old female presented with a rare case of intracranial solitary fibrous tumor (SFT) manifesting as progressive ataxic gait and hearing loss on the left persisting for 6 months with recent symptoms of increased intracranial pressure. Computed tomography demonstrated a large isodense irregular-shaped mass in the left posterior cranial fossa. T2-weighted magnetic resonance imaging showed two components appearing as very low intensity and high intensity. Extreme-lateral suboccipital craniotomy was performed. Gross total resection was achieved except for some dural attachment in the jugular foramen. All symptoms and signs subsided after surgery. Histological, immunohistochemical, and electron microscopic examinations led to a diagnosis of SFT. The strongly hypointense areas on the T2-weighted images were hypocellular region characterized by disorganized spindle cells and thick bands of collagen. The hyperintense areas on the T2-weighted images were hypercellular region mimicking hemangiopericytoma. Strong immunoreactivity for CD34 was also helpful in the diagnosis. Electron microscopy revealed absence of pinocytic vesicles and dense laminae which are characteristic of hemangiopericytoma. The magnetic resonance imaging appearance of SFT seems to be pathognomonic.     

Solitary Fibrous Tumor of the Greater Omentum,Mimicking Gastrointestinal Stromal Tumor of the Small Intestine: A Case Report

Solitary fibrous tumor (SFT) is one of the mesenchymal tumors, which rarely arises in the abdominal space. We report a very rare case of abdominal SFT, mimicking another mesenchymal tumor. A 52-year-old Japanese man was referred to our hospital for further evaluation and treatment of gallbladder polyp. Contrast-enhanced computed tomography (CT) showed an enhanced nodule within the gallbladder, and incidentally, also showed a well-circumscribed mass adjacent to the small intestine. The mass was depicted as slightly high density in plain CT, and with contrast-enhancement, the mass was partially stained in early phase and the stained area spread heterogeneously in delayed phase. Magnetic resonance imaging showed that the abdominal mass was depicted as slightly high intensity on T2-weighted imaging and low intensity on T1-weighted imaging. With double-balloon endoscopy and capsule endoscopy, we did not find any tumor inside the small intestine. These visual findings lead us to diagnose it as gastrointestinal stromal tumor of the small intestine with extraluminal growth. We planned to resect both the gallbladder polyp and the intraperitoneal tumor at the same time for pathologic diagnosis and treatment. When the operation was performed, we found a milk-white lobulated tumor on the greater omentum and the tumor was entirely resected. Microscopically, the gallbladder polyp was diagnosed as tubular adenoma, and the omental tumor was diagnosed as SFT. It is important to bear in mind that omental SFTs sometimes mimic other mesenchymal tumors and should be included in the differential diagnosis of abdominal tumor not revealed by endoscopy.Key words: Mesothelial tumor, Extrathoracic locationSolitary fibrous tumor (SFT) is one of the mesenchymal tumors, which was initially thought to usually arise in the pleura. In recent days, however, there have been several previously reported cases of extrapleural SFT; for example, orbit, thyroid, breast, and so on.¹ Nevertheless, SFTs arising in the abdominal space are still rare; in particular, there have been few reports of omental SFT in the past literature. We herein report a case of SFT of the greater omentum, which mimicked another mesenchymal tumor.     

Severe hypoglycaemia associated with a giant solitary fibrous tumor of the pleura

Solitary fibrous tumors (SFT) of the pleura are a rare neoplasm, with benign biological behaviour. Recurrences are rare, and no distant metastases are described in the literature. SFT can secrete hormone-like substances, responsible for paraneoplastic syndromes. The authors describe a case of severe hypoglycaemia due to insulin-like growth factor II (IGF-2)'s secretion by a giant SFT of the pleura. Hypoglycaemia was controlled by the resection of the tumor. Diagnosis and surgical management of these neoplasms are also discussed.     

A case of benign retroperitoneal cyst of Müllerian type in kidney transplant patient

Müllerian cysts of the retroperitoneum, which considered to be a subtype of urogenital cysts, are extremely rare disease entities. Herein we have presented successful excision from a second kidney transplantation from a brain-dead donor to a 38-year-old woman with previous kidney graft failure. During the second cadaveric kidney transplantation operation, two fist-sized cysts were found in the left retroperitoneal pelvic space extending from the left common iliac artery to the prevesical region, which compromised the iliac vessels for vascular anastomosis. After complete cyst excision, vascular anastomoses were performed. Histologically, the cysts were lined with benign Müllerian-type epithelium. We report a rare case of benign retroperitoneal cyst of the Müllerian type, which was incidentally found during kidney transplant surgery.     

Solitary fibrous tumor of the breast: A case report and the review of the literature

Solitary fibrous tumors (SFT) are rare mesenchymal neoplasms. They were first described as spindle‐cell tumors originating from the pleura, but they may arise in any anatomical site. SFT of the breast is an exceedingly rare clinical entity. Our literature review yielded only 21 cases reported so far. We describe a case of a SFT of the breast in a premenopausal patient who presented with a gradually enlarging palpable breast mass. Diagnostic evaluation and management are discussed along with a review of the relevant literature. There are no pathognomonic imaging findings of SFT of the breast. Complete surgical resection with clear margins is the gold standard of treatment. Thorough immunohistochemical analysis is crucial to obtain a definitive diagnosis. Although most SFTs run an indolent course, in some cases the clinical behavior can be unpredictable and a long‐term follow‐up for all patients is therefore mandatory.