Solitary fibrous tumor of the tongue

ABSTRACT Solitary fibrous tumor (SFT) is a benign mesenchymal neoplasm originally described in pleura with a rare presentation in the oral cavity. Herein, we report a case of a 28-year-old male patient who presented an asymptomatic slow-growing mass in the anterior part of the tongue. Intraoral examination revealed a well-circumscribed mass covered by normal mucosa with a fibrous consistency. Due to non-specific clinical findings, the initial diagnostic hypotheses include benign submucosal neoplasms such as leiomyoma, neurofibroma, SFT, and others. An excisional biopsy was performed. Microscopically, the tumor was surrounded by a thick fibrous capsule; hypo and hypercellular areas were arranged in a storiform pattern with a stroma formed by collagen and abundant vascularization. Tumor cells showed immunopositivity for CD34 and STAT-6 and no expression of CD99, AML, S-100, and Ki-67. According to these findings, the diagnosis of SFT was established. After 24 months, the patient is asymptomatic and has no evidence of recurrence. Although oral involvement is rare, SFT should be included in the differential diagnosis of oral submucosal lesions.

Doege-Potter syndrome associated to metastatic solitary fibrous tumor

ABSTRACT Solitary fibrous tumor (SFT) is a rare fibroblastic mesenchymal neoplasm with an estimated annual incidence of 0.35 per 100,000 individuals. Doege-Potter syndrome is a paraneoplastic syndrome related to solitary fibrous tumor clinically characterized by hypoglycemia, occurring in less than 5% of cases. Herein, we report a case of metastatic SFT associated with recurrent severe hypoglycemia. A 43-year-old male with a noncontributory medical history presented with a painless and progressive growing mass in the right thigh. The histological evaluation rendered the diagnosis of SFT, and tumor resection was performed. One year after the operation, on the oncological follow-up, he was admitted to the emergency unit, manifesting an early-morning seizure associated with a severe hypoglycemia. The laboratory findings of non-islet cell tumor hypoglycemia (NICTH) in the background of a relapsed metastatic solitary fibrous tumor were consistent with the diagnosis of Doege-Potter syndrome. Hepatic embolization associated with oral glucocorticoid was an efficient palliative treatment to control the hypoglycemic crisis and allow hospital discharge.

Case for diagnosis. Single-digit clubbing

Abstract A 58-year-old female patient presented with a single-digit clubbing on the second finger of her right hand two years previously. After investigation with imaging and incisional biopsy, superficial acral fibromyxoma was diagnosed. A brief review on single-digit clubbing and its causes is presented, focusing on superficial acral fibromyxoma.

Primary Cutaneous Solitary Fibrous Tumor on the Back

Solitary fibrous tumors (SFT) are uncommon mesenchymal tumors. SFT have several synonyms including localized fibrous tumor, benign mesothelioma, localized fibrous mesothelioma, and submesothelial fibroma. SFT usually occur in the pleura or other serosal surfaces, but SFT can also develop in extrapleural areas including the nasal cavity, orbit, retroperitoneum, and pelvis. Cutaneous SFT is extremely rare, and more likely to occur in the head and neck region. Histologically, this tumor can mimic a variety of benign and malignant tumors such as dermatofibroma, dermatofibrosarcoma protuberans, spindle cell lipoma or other mesenchymal tumors. Most cases of SFT show non-aggressive clinical courses, with low recurrence rates. Herein, we describe a case of primary cutaneous SFT which presented with huge mass on the back.

Tumor fibroso solitario gigante de pleura en paciente joven / Giant Solitary Fibrous Tumor of the Pleura in Young Patient / Tumor fibroso solitário gigante de pleura em paciente jovem

Resumen Introducción : el tumor fibroso solitario de pleura (TFSP) es una patología poco frecuente, corresponde a menos del 5 % de los tumores primarios de pleura, siendo aún más raros los tumores mayores de 15 cm y aquellos en pacientes menores de 35 años, ya que el pico de incidencia es entre los 60 a 70 años con un solo caso reportado en Colombia. Presentación del caso : paciente femenina de 33 años, sin exposición a asbesto o cigarrillo. Consultó por cuadro de disnea de moderados esfuerzos y dolor dorsal derecho. La tomografía axial computarizada (TAC) contrastada de tórax evidenció una gran masa sólida de contornos lobulados que comprometía el 70 % del hemitórax derecho de origen extrapulmonar y que comprimía la aurícula derecha, la inmunohistoquímica de la biopsia percutánea clasificó la lesión como tumor fibroso solitario. Fue llevada a toracotomía posterolateral derecha extendida, donde se encontró un tumor dependiente de la pleura parietal derecha resecado en su totalidad. Histopatología e inmunohistoquímica del producto de resección quirúrgica, compatibles con tumor fibroso solitario de pleura, tamaño 30 x 23 x 16 cm sin características de malignidad. La evolución posoperatoria fue satisfactoria, con un egreso hospitalario temprano. Discusión : en una paciente joven, el TFSP gigante es inusual, posterior a su diagnóstico, y a pesar de tener algunas características que sugerían malignidad: tamaño y origen en la pleura parietal, la resección quirúrgica fue el tratamiento indicado para este tumor, con posterior confirmación histopatológica compatible con tumor benigno.

Abstract Introduction : The solitary fibrous tumor of the pleura (SFTP) is an uncommon pathology. It corresponds to less than 5 % of the primary tumors of the pleura. Even much rare is to find one solitary fibrous tumor, of more than 15 cm in patients younger than 35 years since the incidence peak is between 60 to 70 years. There has been only one case reported in Colombia. Case presentation : The subject of study was a 33-year-old female patient, no exposure to asbestos or cigarette. The chief complaints of the patient were mild dyspnea and right dorsal pain. Thoracic contrast-enhanced computerized tomography showed a large solid mass of lobulated contours that compromised 70 % of the right hemithorax, of extrapulmonary origin compressing the right atrium. Immunohistochemistry of the percutaneous biopsy demonstrated a solitary fibrous tumor. The patient underwent an extended right posterolateral thoracotomy. We found and completely resected a tumor hanging on the right parietal pleura. Histopathology and immunohistochemistry of the product of the surgical resection were compatible with a solitary fibrous tumor of the pleura, 30 x 23 x 16cm in size, and no malignancy. The evolution after surgery was satisfactory with an early hospital discharge. Discussion : In a young patient, a giant TFSP is unusual. After diagnosis and despite having some characteristics that suggested malignancy: its size and origin in the parietal pleura, surgical resection was the appropriate procedure for this tumor, with subsequent histopathological confirmation compatible with a benign tumor.

Resumo Introdução : o tumor fibroso solitário de pleura (TFSP) é uma patologia pouco frequente, corresponde a menos do 5 % dos tumores primários de pleura, sendo ainda mais estranhos os tumores maiores de 15 cm e aqueles em pacientes menores de 35 anos, pois o pico de incidência é entre os 60 a 70 anos com um só caso reportado na Colômbia. Apresentação de caso : paciente feminina de 33 anos, sem exposição a asbesto ou cigarro. Consultou por quadro de dispneia de moderados esforços e dor dorsal direita. A tomografia axial computadorizada (TAC) contrastada de tórax evidenciou uma grande massa sólida de contornos lobulados que comprometia o 70 % do hemitórax direito de origem extrapulmonar e que comprimia a aurícula direita, imuno-histoquímica da biopsia percutânea classificou a lesão como tumor fibroso solitário. Foi levada à toracotomia posterolateral direita estendida, encontrando um tumor dependente da pleura parietal direita ressecado em sua totalidade. Histopatologia e imuno-histoquímica do produto de ressecção cirúrgica, compatíveis com tumor fibroso solitário de pleura, tamanho 30 x 23 x 16cm sem características de malignidade. A evolução pós-cirúrgica foi satisfatória, conseguindo um egresso hospitalar precoce. Discussão : em uma paciente jovem, o TFSP gigante é inusual, posterior a seu diagnóstico e apesar de ter algumas características que sugeriam malignidade; tamanho e origem na pleura parietal, a ressecção cirúrgica foi o tratamento indicado para este tumor, com posterior confirmação hispatológica compatível com tumor benigno.

Solitary fibrous tumor of the kidney: a report of two cases / Tumor fibroso solitário do rim: relato de dois casos

ABSTRACT Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm, composed of monotonous spindle cells, intermingled with collagen fibers. Kidney location is sporadic, with few reports in literature. We present two cases of 40- and 48-year-old males, one with incidental detection of a peripheral mass; another with hilar lesion perceived following investigation of hematuria. Both revealed a spindle-cell proliferation, without mitosis and necrosis. Immunohistochemical studies: positivity for CD34, CD99 and B-cell lymphoma 2 (Bcl-2). No sign of disease were evident nine and five months after surgery, respectively. SFT is mostly benign, but can show malignant behavior. Morphologic and immunohistochemical characteristics are essential for diagnosis.

RESUMEN Tumor fibroso solitario (TFS) es una neoplasia mesenquimal infrecuente de células fusiformes monótonas, separadas por bandas de colágeno. Localización renal es poco habitual, con escasos casos descriptos. Reportamos dos casos de pacientes masculinos, de 40 e 48 anos, el uno con detección incidental de masaperiférica; el otro con lesión hiliar descubierta en la investigación de hematuria. Los dos revelaronproliferación fusocelular sin necrosis ni mitosis. Inmunohistoquímica: positividad para CD34, CD99 y linfoma de células B2 (Bcl-2). No hay evidencia de recidiva a los nueve y cinco meses de la cirugía, respectivamente. TFS es, por lo general, benigno, pero puede revelar comportamiento agresivo. Características morfológicas y inmunohistoquímicas son esencialespara el diagnóstico.

RESUMO Tumor fibroso solitário (TFS) é uma neoplasia mesenquimatosa rara composta por células fusiformes monótonas, intercaladas por fibras de colágeno. Localização renal é incomum, com escassos casos descritos. Relatamos dois casos do gênero masculino, com 40 e 48 anos, um com detecção incidental de massa periférica; outro com lesão hilar descoberta na sequência de investigação por hematúria. Ambos revelaram proliferação fusocelular sem mitoses nem necrose. Imuno-histoquímica: positividade para CD34, CD99 e linfoma de células B2 (Bcl-2). Não há evidência de recidiva nove e cinco meses após cirurgia, respetivamente. TFS é maioritariamente benigno, mas pode revelar comportamento agressivo. Características morfológicas e imuno-histoquímicas são essenciais para o diagnóstico.

Primary Intraparenchymal Central Nervous System Solitary Fibrous Tumor/Hemangiopericytoma Presenting with Intracerebral Hemorrhage: A Case Report

A 53-year old man who had a left hemiparesis from head injury of traffic accident 20 years ago visited an emergency room with suddenly developed semi-comatose mental status. Brain CT showed 8.6-cm sized solid and cystic mass on right temporal lobe that was associated with hemorrhage. Solid lesion showed a strong enhancement after an administration of contrast media. Because of severe mass effect, emergency operation was performed. The mass was an intraparenchymal lesion with yellowish cystic fluid and the firm reddish-brown solid lesion was hemorrhagic. The lesion was totally resected. Pathologically, anaplastic solitary fibrous tumor/hemangiopericytoma was diagnosed with 70/10 high power fields. Postoperative radiotherapy of 50 Gy was done. Postoperative 2 months later, the patient was recovered to alert mental state. We report this unusual case of non-dural based intraparenchymal solitary fibrous tumor/hemangiopericytoma with high mitotic index and acute massive hemorrhage. Rapid tumor growth of hypervascular tumor might have a chance of bleeding.

CT and MRI finding and clinical feature of extrapleural solitary fibrous tumor / 中国医师进修杂志

Objective To investigate the CT and MRI finding of extrapleural solitary fibrous tumor (ESFT) to improve the preoperative diagnostic ability of such tumors. Methods The clinical data and CT/MRI finding of 11 ESFT patients confirmed by pathology from January 2007 to June 2018 in Jiaxing Traditional Chinese Medicine Hospital Affiliated to Zhejiang Chinese Medicine University were retrospectively analyzed. CT scan was performed in 9 cases and MRI scan in 4 cases. Results Of the 11 patients with ESFT, 6 cases occurred in the abdominal cavity, 3 cases in the cavitas pelvis and 2 cases in the ocular region. All the tumors were solitary, and the maximum diameter of the lesion was (8.3 ± 4.2) cm. The boundary of the tumor was clear in 7 cases, and the boundary was not clear in 4 cases. The tumor form was circular or fusiform in 6 cases and lobulated in 5 cases (some tumors had notch sign). CT scanning presented isodensity or inhomogeneous low density, including 4 cases of cystic degeneration accompanied by inner grid separation, and 3 cases of patchy calcification. The enhanced scanning mass showed 6 cases of geographic enhancement and 7 cases of earthworm drilling soil. MRI T1WI showed slightly lower signal intensity; T2WI fat-suppression sequences showed slightly higher mixed signal intensity in 2 cases and an iso-to high mixed signal intensity in 2 cases; and DWI showed uneven high signal intensity in 3 cases. The solid part of the enhanced scanning showed'fast enhancement and slow washout'. Conclusions ESFT is usually manifested as isolated mass, and its CT and MRI finding has certain characteristics, especially in the diagnosis and differential diagnosis of the disease, such as geographic enhancement and earthworm drilling soil signs.

Frozen Cytology of Meningeal Malignant Solitary Fibrous Tumor/Hemangiopericytoma

A 51-year-old woman presented with severe dizziness. The brain magnetic resonance image revealed a 5.5 cm multiloculated mass with a thick rim in the left temporal lobe. Cytological examination of frozen diagnosis of the mass showed hypercellular sheets of round and rhabdoid cells in a hemorrhagic background, and two mitotic figures were observed. Histologically, the excised dura-based mass consisted of predominantly round cells with small foci of rhabdoid tumor cells in a pseudoalveolar pattern in a hemorrhagic background, and the cells showed nuclear positivity for signal transducer and activator of transcription 6 as well as frequent mitosis. The mass was diagnosed as a grade 3 solitary fibrous tumor (SFT)/hemangiopericytoma (HPC). The cytological diagnosis of SFT/HPC is challenging because of the heterogeneous cytological findings, such as histological heterogeneity, and because there are no standardized cytological criteria for malignant SFT/HPC. Cytological findings, such as singly scattered small cells, hypercellularity, rare ropy collagen, and round and rhabdoid cells with pseudoalveolar pattern, may assist in the diagnosis of malignant SFT/HPC.

Malignant Hepatic Solitary Fibrous Tumor

Hepatic solitary fibrous tumors (SFTs) are mostly benign and rare because of information regarding the clinical symptoms, treatment, and prognosis of their malignant forms is currently lacking. A literature review concerning malignant SFTs revealed that there were a few cases where patients experienced abdominal right upper quadrant (RUQ) pain as their first clinical symptom, and metastases were found after being diagnosed with hepatic SFT. Here, we report a patient who was previously healthy without any clinical symptoms such as RUQ pain or weight loss, but had the appearance of a metastatic mass as the first clinical presentation before a primary hepatic SFT was detected.

Malignant solitary fibrous tumor: a clinicopathological study on 11 cases / 中华普通外科杂志

Objective To study the clinical features,pathological characters,treatment and prognosis of patients with malignant solitary fibrous tumor (MSFT).Methods Retrospective analysis was made on the clinical data of 11 MSFT patients undergoing surgical resection in Beijing Shijitan Hospital from Jan 2010 to Dec 2017.Overall survival (OS) and disease-free survival (DFS) were assessed using Kaplan-Meier methods.Results One patient died of duodenal fistula within a month after surgery,and the other 10 patients recovered with no severe complications.Immunohistochemically,the tumor cells are all positive for CD34 (11/11) and vimentin (10/10) in a different degree.The median OS and DFS for the 10 patients were 49 and 26 months respectively.The 1-,3-,and 5-year OS rates were 89％,56％,42％ respectively.The 1-,3-,and 5-year DFS rates were 79％,34％,23％ respectively.Conclusion MSFT is a malignancy with high recurrence rate.Tumor recurrence was the main cause of death for patients with MSFT.

Endoscopic management of sinonasal hemangiopericytoma: case report and literature review

ABSTRACT Introduction: Hemangiopericytoma is a rare vascular tumor of the sinonasal region, associated with epistaxis and nasal obstruction as the main symptoms. When located in this region, it has special clinical characteristics that differentiate it from others. Case presentation: The following paper reports the case of a 43-year-old female patient presenting with right nasal obstruction and 6 months of evolution associated with mucopurulent rhinorrhea and recurrent right side epistaxis. Physical examination showed a right obstructive mass originating from the cribriform plate. Computed tomography of the paranasal sinuses revealed a complete blockage of the right nasal cavity by a homogeneous content, with soft tissue density and no evident contrast enhancement. The lesion extended superiorly to the cribriform plate but without intracranial or orbital extension. The patient was treated with endoscopic surgery and anatomopathological study revealed sinonasal hemangiopericytoma. The patient had complete remission and subsequent 3-year follow-up without recurrence. Conclusion: The recommended treatment for hemangiopericytoma is total surgical excision with free margins. The results are generally good and the risk of recurrence seems to be associated with incomplete tumor excision. A literature review is presented and its main characteristics are discussed.

RESUMEN Introducción: El hemangiopericitoma es un tumor vascular poco frecuente en la región nasosinusal que se asocia con epistaxis y obstrucción nasal como principales síntomas. Cuando se presenta en esta región, tiene características clínicas especiales que lo hace diferente de otras localizaciones. Presentación del caso: A continuación se presenta el caso de una paciente de 43 años de edad, con síntomas de obstrucción en fosa nasal derecha y 6 meses de evolución asociados con rinorrea mucopurulenta y epistaxis recurrente del lado derecho. El examen físico mostró una masa obstructiva en el lado derecho con origen en la placa cribriforme. Una tomografía computarizada de los senos paranasales reveló un bloqueo completo de la cavidad nasal derecha por un contenido homogéneo, con densidad de partes blandas, sin captación de contraste evidente. La lesión se extendía hacia el lado superior de la placa cribriforme, sin extensión intracraneal u orbitaria. La paciente fue tratada con cirugía endoscópica y el estudio anatomopatológico reveló un hemangiopericitoma sinonasal. La paciente tuvo remisión completa y se realizó seguimiento por 3 años sin recurrencia. Conclusión: El tratamiento recomendado para el hemangiopericitoma es la escisión quirúrgica total con márgenes libres, cuyos resultados son generalmente buenos. El riesgo de recurrencia parece estar asociado con una escisión tumoral incompleta. Se presenta una revisión de literatura, así como comentarios sobre sus características principales.

Extrapleural solitary fibrous tumor with uncommon histology: a clinicopathologic analysis of 7 cases / 中华病理学杂志

Objective@#To investigate the clinicopathologic characteristics, immunophenotypes, and differential diagnostic features of extra-pleural solitary fibrous tumor (SFT) with uncommon histology.@*Methods@#Seven cases of extra-pleural SFT with uncommon histology were collected during January 2015 and December 2016 in Zhejiang Provincal People′s Hospital; the clinical and radiologic features, histomorphology, immunophenotype and prognosis were analyzed. EnVision method was used for immunohistochemical staining of STAT6, CD34 and other differential diagnosis associated markers.@*Results@#There were five male and two female patients, age from 23 to 54 years (mean=39 years). Three tumors were located in the soft tissue of head and neck, two in trunk subcutaneous soft tissue, one in sella region, and one in the kidney. Grossly the tumors ranged from 0.4 to 8.0 cm (mean=3.1 cm). Microscopically, all three head and neck cases resembled giant cell angiofibroma/giant cell subtype SFT, and one case showed sheet-like pattern of the multinucleated syncytial cells, creating a biphasic arrangement similar to myofibroma. Both truncal tumor resembled lipomatous type SFT, with one similar to dermatofibrosarcoma protuberans and the other to atypical spindle cell lipomatous tumor. The sella tumor showed morphology of a conventional SFT with high grade sarcomatous transformation. The renal tumor demonstrated a malignant SFT with entrapped benign renal tubules, mimicking a biphase synovial sarcoma or a malignant mixed epithelial and stromal tumor. By immunohistochemistry, all seven SFTs showed diffuse and strong nuclear reactivity to antibody against STAT6.@*Conclusions@#Extra-pleural SFTs show a significant heterogeneity of morphology and biological behavior which could cause differential confusion.Careful attention to its characteristic histomorphology with the use of STAT6 immunohistochemistry can help distinguish this tumor from its many mimickers.

A Case of Solitary Fibrous Tumor in the Cheek

Solitary fibrous tumor is a rare spindle cell neoplasm of mesenchymal origin that occurs most commonly in the pleura. This tumor can be found in various extrathoracic sites that contain soft tissue. There are few reports of solitary fibrous tumors in the head & neck and only 5 cases of solitary fibrous tumors of the cheek have been reported. A 53-year-old man visited our department complaining of a firm mass in the left cheek. We suspected a schwannoma originating from the infraorbital nerve. The mass was removed via a gingivobuccal approach and was diagnosed as a solitary fibrous tumor.

Solitary fibrous tumor of the lacrimal gland mimicking pleomorphic adenoma / Tumor fibroso solitário de glândula lacrimal simulando adenoma pleomórfico

ABSTRACT Solitary fibrous tumor (SFT) is a rare mesenchymal spindle-cell neoplasm commonly found in the pleura; it is rare in the orbit and extremely rare in the lacrimal gland. We herein report a case of SFT of the lacrimal gland that mimicked a pleo morphic adenoma. We discuss the clinical, radiological, histopathological, and immunohistochemical findings that provided insight and rationale to accurately diagnose this case.

RESUMO Os autores relatam um caso de tumor fibroso solitário (TFS) de glândula lacrimal simulando um adenoma pleomórfico. O TFS é um raro tumor mesenquimal de células fusiformes, comumente encontrado na membrana pleural, raramente en contrado na órbita e extremamente raro na glândula lacrimal. Os autores discutem os achados clínicos, radiológicos, histológicos e imunohistoquímicos que são a chave para o correto diagnóstico desta rara entidade.

Solitary fibrous tumor/hemangiopericytoma of central nervous system: a clinicopathologic analysis of 71 cases / 中华病理学杂志

Objective@#As solitary fibrous tumor (SFT) and hemangiopericytoma (HPC) share the same molecular genetics features, the 2016 WHO classification of central nervous system (CNS) tumors had created the combined term SFT/HPC and assigns three grades. This study aims to investigate the clinicopathologic characteristics, diagnosis, differential diagnosis and prognosis of CNS SFT/HPC.@*Methods@#Seventy-one cases of CNS SFT and HPC were retrospectively reclassified and studied. Histopathological, immunohistochemical and imaging features were analyzed. The follow-up data were analyzed.@*Results@#There were 37 male and 34 female patients. The median age was 48 years (range, 3-77 years). Twelve cases (17%) were WHO grade Ⅰ, 26 (37%) were WHO grade Ⅱ and 33 (46%) were WHO grade Ⅲ. Microscopically the tumor could show traditional SFT phenotype, HPC phenotype or mixed phenotype. Immunochemically, 97%(69/71) were positive for STAT6, with 96%(66/69)showing diffuse strong staining. Approximately 90% were diffusely positive for bcl-2, CD99 and vimentin. The expression rate of CD34 decreased with increasing tumor grade, and the mean expression rate was 78%. SSTR2a was variably expressed in 10% (7/71) of cases including one case showing strong cytoplasmic staining. A few cases expressed EMA, CD57 and S-100 focally. The Ki-67 index ranged from 1% to 50%. Thirty four patients were followed up for 8-130 months; 12 patients(35%)had recurrences, and two (6%) had liver metastases.@*Conclusions@#CNS SFT/HPC is relatively uncommon. There was significant morphological overlap or transition between different grades. STAT6 is a specific marker for the diagnosis of this tumor. Surgical resection is the preferred treatment. WHO grade Ⅱ and Ⅲ SFT/HPC show rates of local recurrence and systemic metastasis, with liver being the most common site of extracranial metastasis.

Expression and significance of STAT6 in solitary fibrous tumor / 中华病理学杂志

Objective@#To study the clinicopathologic features, the differential diagnosis and the expression of STAT6 in solitary fibrous tumor (SFT).@*Methods@#Eighty cases of SFT were evaluated. The expression of STAT6, CD34, CD99 and bcl-2 protein was studied in these cases and in other groups of soft tissue tumors by immunohistochemical EnVision method. The results were analyzed and relevant literature were reviewed.@*Results@#The expression rate of STAT6 in SFT was 97.5% (78/80) and that in other soft tissue tumors was 3.3% (3/90). The difference was significant (P<0.05). The expression rates of CD34, CD99 and bcl-2 were 88.8% (71/80), 76.3% (61/80) and 75.0% (60/80) in SFT, respectively, which were significantly different from STAT6 expression rate (P<0.05).@*Conclusions@#The expression of STAT6 in SFT has high sensitivity (97.5%) and specificity (96.7%). The expression of STAT6 in SFT is higher than that of CD34, CD99 and bcl-2. STAT6 may be a useful marker for clinical diagnosis of SFT.

Radiographic Diagnosis of Spinal Solitary Fibrous Tumor / 中国医学影像学杂志

Purpose To explore the CT and MRI manifestations of spinal solitary fibrous tumor (SFT) to improve the accuracy of imaging diagnosis.Materials and Methods CT and MRI manifestations of eight pathologically confirmed SFT were retrospectively analyzed.CT and MRI scan were performed in 8 cases.The location,shape,size,density/signal,margin,condition of the internal lesion,adjacent bone destruction and reinforcement characteristic were also analyzed.Results Of the 8 patients,4 cases were pathologically confirmed benign and the other 4 cases were malignant.6 cases showed trans-intervertebral foramen dumbbell shaped soft tissue masses,1 case showed lobulated soft tissue mass lying outside the invertebrate canal and 1 case showed long fusiform lying in intradural extramedullary of spinal canal.6 cases had adjacent bone swelling or osteolytic destruction,1 case had compressive bone defect,and 1 cases showed no obvious bone destruction.The tumor showed an equal/mixed density on CT scan.T1WI equal/low signal was seen in MRI scan.Equal/slightly higher T2WI signals were seen in 6 cases and mixed signals in 2 cases.All patients undergoing enhanced scan showed obviously inhomogeneous enhancement.Conclusion Spinal solitary fibrous tumors are lobulated or dumbbell shaped and growth clinging to or surround the dura mater.The feature of MRI signal is evident that T1WI is mostly equal/low signal and T2WI is usually slightly higher/equal signal,often accompanied by bone destruction.

Malignant Solitary Fibrous Tumor with Heterologous Rhabdomyosarcomatous Differentiation: A Case Report

Malignant solitary fibrous tumor (MSFT) is a well-described entity, from which heterologous differentiation is extremely rare. We encountered a case of MSFT with rhabdomyosarcomatous differentiation in a 56-year-old man. This patient presented with a large mass in his posterior thigh. He had been treated with chemoradiation for sarcoma involving the cervical spine, right femoral head, and both lungs 6 months earlier. A wide excision was performed. The mass measured 10.6 cm and showed a fish-flesh cut surface with necrotic foci. Microscopically, the tumor showed heterogeneous cellularity with a hemangiopericytic vascular pattern. A hypercellular area showed spindle cells or epithelioid cells with high mitotic activity (63/10 high-power fields) and immunoreactivity for CD34 and CD99. A hypocellular area and a cystic area showed pleomorphic rhabdoid cells with immunoreactivity for desmin and myogenin. This is a report of a rare case of MSFT with rhabdomyosarcomatous differentiation and presents new histologic features of MSFT.