Solitary fibrous tumor: Two cases report with a focus on the differential diagnosis / Tumor Fibroso Solitário: Relato de dois casos com foco no diagnóstico diferencial

Solitary fibrous tumor (SFT) is a neoplasm of fibroblastic/myofibroblastic origin with intermediate biological behavior. We report here two cases of SFT affecting an unusual anatomical site in 58-year-old and 40-year-old female patients and discuss the differential diagnosis of this lesion. In case 01, the lesion showed the clinical appearance of an asymptomatic "blister" with normal color, rubbery consistency, measuring 0.3 cm, and affected the lower lip; while in case 02, a symptomatic red nodular lesion with a soft consistency and measuring 0.5 cm affected the floor of the mouth. Excisional biopsies were performed. Microscopically, two well-delimited benign neoplasms were observed, exhibiting the proliferation of ovoid to spindle-shaped mesenchymal cells, vascular spaces with staghorn arrangement, and the absence of mitosis figures. Immunohistochemistry was performed in case 01 to assist in the diagnosis. Weak and diffuse immunostaining was observed for α-SMA and intense and diffuse immunopositivity for Bcl-2 and CD34. Based on histopathological and immunohistochemical features, a diagnosis of SFT was rendered in both cases. The low occurrence and nonspecific clinical features of oral SFT may make its clinical diagnosis difficult. Also, morphological and immunohistochemical are essential for differential diagnosis with other mesenchymal neoplasms.(AU)

O tumor fibroso solitário (TFS) é uma neoplasia de origem fibroblástica/miofibroblastica com comportamento biológico intermediário. Nesse artigo relatamos dois casos de TFS afetando sítios anatômicos incomuns em pacientes do sexo feminino de 58 anos e 40 anos e discutir os seus diagnósticos. No caso 01 clinicamente a lesão apresentou um aspecto de "bolha" assintomática, coloração normal da mucosa, consistência borrachoide medindo 0,3 cm, em região de lábio inferior, enquanto que no caso 02, como uma lesão sintomática, vermelha, nodular com consistência mole e medindo 0,5 cm afetando o assoalho bucal. As biópsias excecionais foram realizadas. Microscopicamente, observamos duas lesões neoplásicas bem delimitadas exibindo uma proliferação de células mesenquimais variando de ovoides a fusiformes, vasos sanguíneos em formato de "chifre de veado", com ausência de figuras de mitoses. No caso 01 foi realizado análise imuno-histoquímica para auxiliar no diagnóstico. Foi observado uma marcação fraca e difusa de α-SMA e uma intensa e difusa imunopositividade para o Bcl-2 e CD34.Baseado nos achados histopatológicos e imuno-histoquímicos o diagnóstico de TFS foi estabelecido em ambos os casos. A baixa ocorrência e os achados clínicos inespecíficos do TFS oral podem dificultar o diagnóstico clínico. Além disso, as análises morfológicas e imuno-histoquimicas são essenciais para realização do diagnóstico diferencial com outras neoplasias mesenquimais.(AU)_

El análisis inmunohistoquímico para el diagnóstico del tumor fibroso solitario/hemangiopericitoma / Immunohistochemical analysis for the diagnosis of solitary fibrous tumor/hemangiopericytoma

Resumen El tumor fibroso solitario/ hemangiopericitoma (TFS/HP) es un tumor extraaxial de origen mesenquimático de infrecuente observación, que usualmente se confunde con el meningioma, del cual puede ser clínica y radiológicamente indistinguible. El análisis molecular con la detección de la expresión nuclear STAT6 (signal transducer and activator of transcription 6) o la fusión NAB2-STAT6 (NGFI-A binding protein 2) es recomendable para confirmar el diagnóstico. Presentamos 3 casos clínicos, 2 mujeres y 1 varón, con diagnóstico anatomopatológico de meningioma meningotelial en el primer caso; y los casos 2 y 3 con sospecha radiológica de meningioma. La revisión anatomopatológica con estudio molecular permitió certificar el diagnóstico de TFS/ HP. Para el diagnóstico diferencial entre TFS/HP meníngeo y meningioma, se recomienda buscar la expresión de STAT6 como primer paso o la fusión NAB2-STAT6. La revisión de las muestras de biopsia debe estar garantizada en todos los pacientes, inclusive en aquellas que fueron estudiadas en Servicios de Patología Nivel 3.

Abstract The solitary fibrous tumor/ hemangiopericytoma (TFS/HP) is a rare mesenchymal extraaxial tumour. TFS/HP can sometimes be difficult to distinguish from other extra-axial tumors like meningioma, which can be clinically and radiologically indistinguishable. Molecular analysis with STAT6 (signal transducer and activator of transcription 6) nuclear expression or NAB2-STAT6 (NGFI-A binding protein 2) fusion is recommended to confirm the diagnosis. We present 3 cases, 2 women and 1 male, with pathological diagnosis of meningothelial meningioma in the first case; cases 2 and 3 with radiological suspicion of meningioma. The pathological review with molecular study certified the diagnosis of TFS/HP. For differential diagnosis between meningeal TFS/HP and meningioma, it is recommended to look for STAT6 expression as a first step, or NAB2-STAT6 fusion in order to confirm TFS/HP. The review of biopsy samples must be guaranteed in all patients, including those who were studied in Pathology Services Level 3.

Tumor fibroso solitario del lóbulo caudado del hígado / Solitary fibrous tumor of the liver caudate lobe

Introduction: Solitary fibrous tumor of the liver (SFTL) constitutes such a rare finding that it has been published only as case reports and to the present date there are only 45 cases published in English medical literature. This article describes the case of a patient treated at our institution with SFTL. Case report: A male 59-years-old patient was diagnosed with a SFTL incidentally found in a computed abdominal tomography taken by another causes, tumor was originating from the caudate lobe. The patient was asymptomatic. At surgery, the tumor was observed originating directly from the caudate lobe through a pedicle measuring approximately 3 cm. The tumor was resected sectioning its implantation pedicle and ligating all arterial, venous and biliary vessels. The SFTL was well encapsulated, measured 15 x 9 x 6 cm and weighted 794 g. The histological diagnosis was a SFTL and was confirmed by immunohistochemistry with monoclonal antibodies that reacted positively to CD34 and vimentin and negatively to CD117, S100, smooth-muscle α-actin and desmin. Conclusions: SFTL is an uncommon tumor. The present case is the first reported in Chilean medical literature and presented all the habitually described radiologic, surgical and pathological characteristics.

Introducción: El tumor fibroso solitario del hígado (TFSH) constituye un hallazgo tan raro que se ha publicado únicamente como reportes de caso y hasta el presente se encontraron sólo 45 casos publicados en la literatura inglesa. El presente artículo describe el caso de un paciente que fue tratado en nuestra institución por un TFSH. Reporte de caso: Paciente masculino de 59 años de edad al que, en una tomografía abdominal computarizada que se tomó por otras causas, se encontró en forma incidental un gran tumor hepático localizado en el lóbulo caudado del hígado. El paciente no refería síntomas relacionados con el tumor. En la cirugía se observó que el tumor se originaba directamente del lóbulo caudado al cual lo unía un pedículo de aproximadamente 3 cm de diámetro transverso. Se seccionó el tumor desde su base de implantación en el hígado ligándose los vasos arteriales y venosos así como los conductos biliares que se encontraron. Este medía 15 x 9 x 6 cm y pesaba 794 g, se encontraba bien encapsulado. El diagnóstico histológico fue el de un TFSH, el cual se confirmó mediante inmunohistoquímica con anticuerpos monoclonales que resultaron positivos para CD34 y vimentina en las células tumorales y negativos para CD117, S100, α-actina de músculo liso y desmina. Conclusiones: El TFSH es un tumor raro. El presente caso de un TFSH es el primero reportado en la literatura médica chilena y presentó las características radiológicas, quirúrgicas y patológicas habitualmente descritas en estos casos.

Tumor fibroso solitário retroperitoneal volumoso / Giant solitary fibrous tumor of retroperitoneum

O tumor fibroso solitário (TFS) é uma neoplasia mesenquimal rara caracterizada pela proliferação de células fusiformes, geralmente acometendo a pleura. É diagnosticado, de modo geral, após estudo anátomo-patológico e por imuno-histoquímica, já que muitas vezes encontra-se em local pouco usual e assemelha-se a outras neoplasias. Relatamos o caso de um paciente de 46 anos com massa retroperitoneal compatível com tumor fibroso solitário de baixo grau (AU)

The sol itary fibrous tumor (SFT) is a rare mesenchymal neoplasm characterized by proliferation of spindle cells, usually affecting the pleura. It is usually diagnosed after pathological study and by immunohistochemistry, as it is often located in an unusual location and resembles other cancers. Here we report the case of a 46-year-old patient with retroperitoneal mass consistent with low grade solitary fibrous tumor (AU)

Tumor fibroso solitário renal: relato de caso clínico / Solitary fibrous tumor of the kidney: a case report

We describe a case report of a rare cancer affecting the kidney of 63 years of age patient who underwent imaging studies from ultrasound, computed tomography, and magnetic resonance imaging, due to complaints: left back pain and urinary obstruction. Sonographic and radiological features of the mass found suggested the diagnosis of a malignant tumor of parenchymal origin. The pathological and immunohistochemical studies of the resected anatomical specimen, however, diagnosed a rare benign variant of solitary fibrous tumor originating in the inferior pole of the left kidney...

Descrevemos o relato de caso de uma rara neoplasia acometendo o rim de um paciente de 63 anos de idade que foi submetido a estudos de imagem por ultrassonografia, tomografia computadorizada e ressonância magnética nuclear devido às queixas apresentadas: dor lombar à esquerda e alterações miccionais sugestivas de obstrução infravesical. As características ultrassonográficas e radiológicas da massa encontrada sugeriam o diagnóstico de uma neoplasia maligna de origem parenquimatosa. O estudo anatomopatológico e imuno-histoquímico da peça anatômica ressecada, entretanto, concluiu o quadro como variante benigna do raro tumor fibroso solitário originário do polo inferior do rim esquerdo...

Tumor fibroso solitário de laringe: relato de dois novos / Solitary fibrous tumor of the larynx: report of two new cases

Solitary fibrous tumor is a rare neoplasm. Few cases have been described in the head and neck area, and less than 11 were located in the larynx. We described two new cases of solitary fibrous tumor of the larynx. A man, 64-year-old, and a woman, 77-year-old, both with submucosal and nodular supraglottic lesions, were submitted to surgical treatment and both showed CD-34 and bcl-2 immunoreactivity and S-100 and smooth-muscle actin negativity. After 24 and 22 months of postoperative follow-up, respectively, they did not show signs of active disease...

O tumor fibroso solitário é uma neoplasia rara. Foram descritos poucos casos em cabeça e pescoço, sendo não mais de 11 na laringe. Descrevemos dois novos casos de tumor fibroso solitário da laringe, um em um homem de 64 anos e outro em uma mulher de 77 anos, ambos com lesões supraglóticas submucosas e nodulares. Os casos foram submetidos a tratamento cirúrgico e ambos apresentaram imunorreatividade a CD-34 e bcl-2, e negatividade para S-100 e actina de músculo liso. Após 24 e 22 meses de seguimento pós-operatório, respectivamente, não apresentam sinais de doença em atividade...

Tumor fibroso solitario gigante retro peritoneal: a propósito de un caso / Giant retroperitoneal solitary fibrous tumor: report of a case

El tumor fibroso solitario es una neoplasia fuso celular, poco común de localización pleural frecuentemente. Presentamos un caso de presentación crónica evidenciándose masa palpable identificando tumoración de 35 x 20 x 15 cm. Diagnosticándose por anatomía patológica tumor fibroso solitario gigante (TFSG). En la revisión bibliográfica sobre los tumores diagnosticados como TFSG es muy infrecuente, siendo el primero reportado en nuestro medio.

Giant solitary fibrous tumor (TFSG) is a spindle cell neoplasm, uncommon, being pleural a common site. We report a case of chronic presentation of 4 months duration with a palpable mass. We found, a tumor 35 x 20 x 15 cm .In the literature tumors diagnosed as TFSG are very rare, the first reported in our country.

Solitary fibrous tumour of lung.

Fibrous tumours arising entirely within the substance of the lung are rare. We report one such rare case in whom the diagnosis was established after surgical removal.

Tumor fibroso solitario del tiroides / Solitary fibrous tumor of the thyroid

Solitary fibrous tumor (SFT) is a rare spindle cell neoplasm mostly found in the pleural tissue but also described in other parenchymas. There are twenty four cases of thyroid SFT, all of them with similar histological appearance and immunohistochemical reaction pattern. We report the case of a thyroid tumor in a thirty year old man. The tumor was characterized by a proliferation of spindle cells arranged in a storiform and hemangiopericitoid pattern, without cell atypia and necrosis, and with low mitotic rate. The tumor showed a strong positive immunohistochemical reaction for CD-34 and bcl-2. There were no reactions for Desmin, Pancytokeratin and S-100. All of these features confirm the diagnosis of a thyroid SFT. It is important to know that this entity can arise in the thyroid gland to direct the analysis in a correct way.

El tumor fibroso solitario (TFS) es una neoplasia de células fusadas, de muy baja frecuencia, encontrada mayormente en la pleura pero también descrita en sitios extrapleurales. En la literatura se han reportado 24 casos de TFS originados en el tiroides, todos con características patológicas e inmunohistoquímicas (IHQ) similares. Reportamos el caso de un tumor tiroideo en un hombre de 30 años. El tumor se caracterizó por ser una proliferación de células fusadas dispuestas en un patrón estoriforme y hemangiopericitoide, sin necrosis ni atipias, con baja actividad mitótica. El estudio IHQ presentó positividad para CD34 y bcl-2 y negatividad para Desmina, Pancitokeratina y S-100, características concordantes con un TFS. Es importante saber que esta entidad puede surgir en el tiroides y así poder orientar el estudio para su diagnóstico correcto.

Hepatic solitary fibrous tumor: Report of a rare case.

Solitary fibrous tumor (SFT) of the liver is an extremely rare neoplasm of mesenchymal origin. In the English literature, less than 40 cases of SFTs of the liver have been reported. The present case concerns a 34-year-old female who presented to us with complaint of dyspepsia. On examination, there was hepatomegaly. On ultrasound examination, an SOL in the liver was detected. Large tumor measuring 14.5 × 10 × 8 cm was resected. Microscopic evaluation of the tumor showed a well-circumscribed, low to moderately cellular tumor demonstrating spindle- and fibroblast-like cells within the collagenous stroma. Immunohistochemistry revealed diffuse strong cytoplasmic immunopositivity of CD34, Bcl2, and vimentin. A diagnosis of a benign SFT was given. The patient remained well 4 years after surgery. SFT is a rare mesenchymal neoplasm that occasionally involves the liver in adult patients. Most SFTs are benign, but some may have malignant histological features. With less than 40 reported cases in the literature, little can be said regarding its natural history or the benefits of adjuvant radio chemotherapy. Complete surgical resection remains the cornerstone of its treatment.

Malignant Solitary Fibrous Tumor of Retroperitoneum Mimicking Gastric Submucosal Tumor / 대한소화기학회지

Solitary fibrous tumors (SFTs) are an uncommon neoplasm characterized by the proliferation of spindle cells. The diagnostic criteria of malignant solitary fibrous tumors (MSFTs) include high cellularity, high mitotic activity (4>10 HPF), pleomorphism, hemorrhage and necrosis. This tumor frequently involves the pleura and MSFTs of retroperitoneum mimicking gastric submucosal tumor are very rare. We report a rare case of MSFT that presented as a gastric submucosal tumor. A gastroscopic examination showed a large bulging mucosa in the gastric body. Abdominal computed tomography revealed a well-defined heterogeneous enhancing mass between the left hepatic lobe and gastric body. Surgical resection was performed and histologic features were consistent with a MSFT.

Solitary Fibrous Tumor of the Pancreas: Imaging Findings

We report here a case of a pathologically proven solitary fibrous tumor of the pancreas. A 54-year-old man was referred to our hospital for further evaluation of a pancreatic mass that was found incidentally. CT, MR imaging, and endoscopic ultrasonography showed a well-defined, enhancing mass with cystic portions of the pancreas body. MR cholangiopancreatography showed no pancreatic duct dilatation. A solitary fibrous tumor of the pancreas is a very rare lesion.

Myxoid Solitary Fibrous Tumor of the Retroperitoneum: MRI Findings with the Pathologic Correlation

We report here on a case of solitary fibrous tumor of the retroperitoneum, and the tumor displayed a predominantly myxoid histology. A 56-year-old man presented with an incidentally detected retroperitoneal mass. On the MR images, the mass was observed as having iso-signal intensity on the T1-weighted images and high signal intensity on the fat-saturated T2-weighted images. The mass showed intense enhancement on the Gd-DTPA enhanced T1-weighted images. At surgery, a well-defined solid mass was found in the left retroperitoneum. The histological diagnosis was made as solitary fibrous tumor with a predominantly myxoid histology.