Hipoglucemia tumoral dependiente y no dependiente de células ß-pancreáticas, un reto diagnóstico / Tumor and non-tumor mediated hypoglycemia by pancreatic beta cells, a diagnostic challenge

La hipoglucemia es una urgencia médica frecuente que en la mayoría de los casos es secundaria al uso de fármacos hipoglucemiantes, orales o inyectados, indicados en pacientes con diabetes mellitus. No obstante, puede presentarse en forma espontánea y severa relacionándose con múltiples condiciones clínicas, incluyendo las neoplasias. Ante una hipoglucemia de origen paraneoplásico se deben reconocer los mecanismos fisiopatológicos que la generan y establecer el diagnóstico oportuno y preciso para disminuir las complicaciones propias de este síndrome clínico. Presentamos dos pacientes con cuadro de hipoglucemia refractaria al manejo médico inicial, de aparición similar con patologías diferentes. El primer caso corresponde a un paciente con insulinoma y el segundo con un hemangiopericitoma.

Hypoglycemia is a common medical emergency which is mostly secondary to the use of oral or injected hypoglycemic drugs indicated in patients with diabetes mellitus. However, it can present spontaneously and severely in relation to multiple clinical conditions, including neoplasms. When faced with hypoglycemia associated with paraneoplastic disorders, the pathophysiological mechanisms of hypoglycemia must be recognized and a timely and accurate diagnosis must be established in order to diminish complications inherent to this clinical syndrome. We herein present two patients with hypoglycemia refractory to initial medical management, sharing similar appearance with other pathologies. The first case corresponds to a patient with an insulinoma and the second to a patient with a hemangiopericytoma.

Doege-Potter Syndrome: A presumptive case of Metastatic hemangiopericytoma with Persistent hypoglycemia in a 27-year-old male / Journal of the ASEAN Federation of Endocrine Societies

@#Doege-Potter syndrome (DPS) is a rare paraneoplastic condition characterized by hypoinsulinemic hypoglycemia from a solitary fibrous tumor. The underlying mechanism is the secretion of a prohormone form of insulin-like growth factor II (IGF-II) by the tumor, which causes decreased release of glucose into the circulation. We report the case of a 27-year-old Filipino male with presumptive DPS from a recurrent right temporo-zygomatic hemangiopericytoma (HPC). The complexity of DPS requires a multidisciplinary approach. Early screening for metastases from HPC may prevent the undesirable sequelae of the disease process.

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.

Hemangiopericitoma primario de pulmon como hallazgo incidental. reporte de dos casos / Primary pulmonary hemangiopericytoma as an incidental finding. two case report

El hemangiopericitoma intra-pulmonar es una neoplasia poco frecuente, que se origina a partir de lo pericitos que rodean la membrana basal de capilares y vénulas dentro del parénquima pulmonar. Presentar dos casos clínicos como hallazgo incidental en su presentación conocer comportamiento y manejo de dicha neopla Paciente masculino 40 años cuadro clínico caracterizado por tos seca persistente, cansancio con dificultad para respirar con progresión a disnea rápida a pequeños esfuerzo y pérdida de peso. Paciente femenina de 37 años cuadro clínico caracterizado por dolor torácico tipo opresivo en región latero posterior de hemitórax erecho, con irradiación al hombro, radiografía de tórax póstero-anterior, se descubrió múltiples imágenes nodulares parenquimatosas bilaterales a nivel central y sub-pleural. Segundo paciente se realiza radiografía de tórax póstero-anterior se observa patrón de masa tumoral localizada en el centro del pulmón derecho, las cuales fueron confirmadas por tomografía computada de tórax. Se procedió a la recesión quirúrgica de dicha lesión para biopsia, mientras que en la paciente femenina la conducta fue más radical se practicó umonectomía derecha. Evolucionan satisfactoriamente. Reporte de biopsia y de inmunohistoquímica: emangiopericitoma primario de pulmón/tumor fibroso solitario. Ambos pacientes fueron referidos al servicio de oncología médica para terapia adyuvante.Tumor poco frecuente, su patogénesis es todavía desconocida y aunque es un tumor en apariencia y comportamiento benigno, debe tratarse como potencialmente maligno, se debe ser radical en el tratamiento y realizar un seguimiento cuidadoso, continuo y estricto del paciente(AU)

Intrapulmonary hemangiopericitoma potentially is a rare malignancy, which originates from the pericytes that surround the basal membrane of the capillaries and venules in lung parenchyma. The aim is to resent two cases as an incidental finding in its presentation and also know the behavior and management of this neoplasm. A male patient of 40 years with clinical picture haracterized by persistent dry cough, fatigue with shortness of breath with rapid progression to small effort dyspnea and weight loss and a female patient aged 37 clinical picture characterized by chest pain ppressive kind in lateral region posterior right chest, radiating to the shoulder in the chest film, multiple nodular parenchymal bilateral central and sub-pleural. The second patient so poster anterior chest radiograph where a pattern of tumor mass located in the center of the right lung, which was confirmed by computed tomography of the chest, is observed is performed. In the patient he proceeded to the surgical recession of the injury to biopsy, while in the female patient's behavior was more radical right neumonectomy was practical. They are evolving satisfactorily. Report biopsy and mmunohistochemistry for primary lung: Hemangiopericitoma / SFT. Both patients were referred to medical oncology service for adjuvant therapy. Is a rare tumor, its pathogenesis is still unknown and although a tumor in appearance and benign behavior, should be treated as malignant potential, must be radical in treatment and careful monitoring, continuous and strict patient(AU)

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.

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.

Solitary Fibrous Tumor of Breast with Anaplastic Areas (Malignant Solitary Fibrous Tumor): A Case Report with Review of Literature / 한국유방암학회지

Solitary fibrous tumor (SFT) is a rare, soft tissue neoplasm that rarely presents in breast tissue, with only 27 previously reported cases. To our knowledge, only one case of malignant SFT has been reported in the English literature. A 75-year-old Caucasian woman presented to our institution with a 3-month history of a palpable left breast mass. No other symptoms, including nipple discharge or skin changes, were noted. She underwent 3 previous biopsies for right breast masses, all of which were benign, with no evidence of spindle cell neoplasm, atypical hyperplasia, or malignancy. Microscopic examination of the mass demonstrated a classic area of SFT with areas of high-grade anaplastic component. In these areas, the tumor showed atypical epithelioid cells arranged in hypercellular sheets with diminished branching vasculature, nuclear pleomorphism, and increased mitotic count (up to 9/10 high-power fields). This case represents the second case of malignant SFT in the breast.

Solitary Fibrous Tumours/Hemangiopericytomas of the Maters(Meninx):A Clinicopathologic Analysis / 中国医学科学院学报

To study the clinicopathologic characteristics,immunohistochemical features,differential diagnosis,and prognosis of solitary fibrous tumours(SFT)/hemangiopericytomas(HPC)in the maters(meninx). Methods A series of 7 cases previously diagnosed as SFT/HPC at the Department of Pathology,Peking Union Medical College Hospital,during the period from 2008 to 2018 were analyzed for clinical data,histopathology,and immunohistochemical findings.The patients were followed up and the relevant literatures were reviewed. Results These seven patients included two males and 5 females aged 22 to 77 years(mean,49 years).Headache was the most common symptom.The magnetic resonance imaging of SFT/HPC showed irregularly contoured masses and dural tail sign was observed at the periphery of the lesion in 4 cases.The major axis of the tumor ranged from 1.8 cm to 10 cm(mean,4 cm).The tumors were located in the mater in 6 cases and in the spinal meninx in 1 case.The tumors were surgically removed in all cases.Under light microscope,the tumors were formed by long round,oval or spindle cells,with rich branching vascular pattern and varying quantity of collagenous fibers bands in both sparse areas and dense areas.According the WHO classification,2 cases were in WHO grade Ⅰ,2 cases in WHO grade Ⅱ,and 3 cases in WHO grade Ⅲ.Immunohistochemistry of the paraffin-embedded tissues in all cases showed positive immunoreativity for CD34 and vimentin in all seven cases,along with positive signal transducer and activator of transcription 6 in 4 cases,negative epithelial membrane antigen and S-100 in 7 cases,and negative progestational hormone and somatostatin receptor 2 in 6 cases.The Ki-67 index ranged from 1% to 15%.Five patients with follow-up data(including 1 current case)were alive,while 2 patients were lost to follow-up. Conclusions The SFT/HPC are rare in the maters(meninx)and is clinically difficult to be differentiated from other meningioma.The combination of CD34 and signal transducer and activator of transcription 6 helps to diagnose this disease.

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.

Glomangiopericytoma of the Spinal Cord

Glomangiopericytoma, also referred to as a hemangiopericytoma-like tumor or sinonasal type hemangiopericytoma, is a rare tumor of the nasal cavity and paranasal sinus that has never been reported in the spinal cord. Here, we report a case of a 47-year-old man who developed glomangiopericytoma in the thoracic spine. This lesion showed a heterogeneous high signal intensity compared to the spinal cord on a T2-weighted image and an easily enhanced isointense signal on a T1-weighted image.

Glomangiopericitoma: reporte de un caso / Glomangiopericytoma: a case report

El glomangiopericitoma es un tumor nasosinusal extremadamente raro, más frecuente en pacientes de edad avanzada y en mujeres. Si bien su etiopatogenia es desconocida, se reconocen ciertos factores predisponentes tales como hipertensión arterial, embarazo, trauma y uso de corticoides. Para su diagnóstico, resulta necesario recurrir tanto a estudio por imágenes como a la histología y técnicas de inmunohistoquímica. Microscópicamente se caracteriza por un prominente crecimiento perivascular de células uniformes ovales o fusiformes, dispuestas en fascículos cortos intercalados con capilares de diámetros variables ramificados en "asta de ciervo" y presenta inmuno-rreactividad positiva para actina, factor XIII-A y vimentina principalmente. Clínicamente este tumor presenta un comportamiento generalmente benigno, pero con una elevada tasa de recurrencia. Presentamos el caso de una mujer de 71 años, con antecedentes de hipertensión arterial, que acudió a nuestro centro por rinorrea purulenta y epistaxis unilateral derecha de 5 años de evolución. Al examen se observa masa polipoidea en fosa nasal derecha con abundante vascularización, sin otros hallazgos al examen físico. La lesión es resecada en su totalidad mediante cirugía endoscópica. El estudio histológico e inmunohistoquímico son compatibles con glomangiopericitoma. La paciente evoluciona con remisión de su sintomatología y a los dos meses desde la resección no ha presentado evidencias de recurrencia.

Glomangiopericytoma is an extremely rare sinonasal tumor, more common among elderly and women. Although its etiology and pathogeny are unknown, there are certain predisposing factors, such as arterial hypertension, pregnancy, trauma and corticosteroids. To diagnose this tumor, it is necessary imaging, histopathologic and inmunohistochemical studies. At the microscopic study, it is characterized by a prominent perivascular growth of oval-shaped or fusiform cells, arranged in short fascicles separated by capillary vessels of variable diameters, with staghorn-like ramifications, and lmmunohistochemistry positive mainly for actin, XIII-A factor and vimentin. Clinically, this tumor has a generally benign behavior, but with high recurrence percentage. We present the case of a 71 years old woman, with history of hypertension, who present in our center with a 5 years history of purulent rhinorrhea and right unilateral epistaxis, at the physical exam there is a polypoid mass in the right nasal fossa with rich vascularization, with no other findings. This tumor was resected entirely with endoscopic surgery. Histology and immunohistochemistry were compatible witch gomangiopericytoma. The patient evolve with remission of her symptoms and with no signs of recurrence at two-month follow-up.

Tumor fibroso solitario meníngeo / Meningeal fibrous solitary tumor

Se presenta caso de paciente masculino de 28 años, sin antecedentes médicos de importancia, con síndrome convulsivo primer evento. Se le realiza estudio de imagen donde se documenta lesión ocupativa extraaxial temporo ­ occipito ­ cerebelar derecha. Paciente es llevado a resección de tumor. Se obtiene hallazgo histopatológico de tumor fibroso solitario meningeo. Además se documenta foco irritativo cortical a este mismo nivel. El tumor fibroso solitario meningeo representa un espectro de tumores mesenquimales, agrupado actualmente por la Clasificación de la OMS como Tumor fibroso solitario/ Hemangiopericitoma grado 1. El tratamiento se basa en resección quirúrgica amplia y vigilancia a largo plazo...(AU)

Hemangiopericitoma de Bexiga: relato de uma patologia rara / Hemangiopericytoma of the bladder: report of a rare disease

A maioria dos tumores da bexiga é formada por células transicionais. Hemangiopericitoma é um tumor de tecidos moles e apresenta grande variabilidade histológica e ocorrência extremamente rara na bexiga. Neste trabalho é relatado um caso de hemangiopericitoma de bexiga em um paciente de 23 anos. Os achados clínicos e anatomopatológicos deste tumor são discutidos no presente relato, com revisão da literatura(AU)

Most bladder tumors are formed by transitional cells. Hemangiopericytoma is a soft tissue tumor which presents great histologic variability and extremely rare occurrence in the bladder. Here the authors report a case of hemangiopericytoma of the bladder in a 23-year-old patient. The clinical and pathological features of this tumor are discussed in this report with a literature review(AU)

Hemangiopericitoma cerebral en paciente adolescente: reporte de un caso y revisión de literatura / Cerebral hemangiopericytoma in adolescent patient: case report and literature review

Introducción: En 1942 Stout y Murray describieron un tumor extraneural compuesto por una proliferación de vasos sanguíneos con endotelio normal rodeados de células neoplásicas que presumiblemente surgían de los Pericitos. La Neoplasia fue llamada Hemangiopericitoma. Se trata de un tumor agresivo, más frecuente en adultos. En los niños son extremadamente raros, solo 11 casos han sido reportados en la literatura. Se originan de la transformación maligna de los Pericitos de Zimmerman. Descripción del caso: Presentamos el caso de una adolescente de 16 años, con antecedente de convulsiones generalizadas en el año 2009, detectándose en el 2014 lesión ocupante de espacio parieto-occipital derecha, la cual es extirpada, informándose como meningioma. Evoluciona con recidiva tumoral 3 meses más tarde, evaluándose por inmunomarcación nueva muestra de lesión, con la que se arriba al diagnóstico de hemangiopericitoma. Conclusión: El Hemangiopericitoma cerebral es una patología rara, de muy baja prevalencia, y de gran similitud clínica e imagenológica con los meningiomas. Incluso genera gran cantidad de diagnósticos erróneos con la histopatología convencional. Por todo lo antes mencionado, es muy importante tener presente esta patología a la hora de pensar en diagnósticos diferenciales de meningiomas, siendo fundamental la inmunomarcación para confirmar uno u otro diagnóstico.

Introduction: In 1942, Stout and Murray described an extraneural tumor composed of a proliferation of blood capillaries with normal endothelium and surrounded by neoplastic cells, which presumably arose from pericytes. The neoplasm was thus labeled an hemangiopericytoma. This aggressive tumor is more common in adults than in children, in whom it is extremely rare, with only 11 cases reported in the literature. It stems from the malignant transformation of pericytes of Zimmerman. Case report: We present the case of a 16-year old teen with a history of generalized seizures in 2009, in whom a spaceoccupying parieto-occipital lesion was detected and removed in 2014, at which time it was diagnosed as a meningioma. However, upon tumor recurrence three months later, further immuno-staining revealed the lesion to be a hemangiopericytoma. Conclusion: Cerebral hemangiopericytomas have a very low prevalence and high degree of clinical and imaging similarity with meningiomas. This similarity frequently leads to misdiagnosis with conventional histopathology. For this reason, it is crucial to remember this pathology in the differential diagnosis of a meningioma, so that appropriate immuno-staining is performed to either confirm or rule out its presence.

Clinical Features and Outcomes of a Rare Nasal Cavity Tumor Glomangiopericytoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Glomangiopericytoma falls within the category of borderline low-malignant-potential soft tissue tumors of the nose and paranasal sinuses. It is a rare tumor arising from the pericytes surrounding capillaries, and accounts for less than 0.5% of all sinonasal tumors. The aim of this study was to analyze the clinical manifestation and surgical outcomes of the glomangiopericytoma in the nasal cavity. SUBJECTS AND METHOD: Medical records of eight patients who were surgically managed for glomangiopericytoma of the nose and paranasal sinuses from 2000 to 2015 were retrospectively reviewed. Clinical features, size, Immunohistochemical staining, extent of surgery, adjuvant treatment, and recurrence were evaluated. RESULTS: Eight patients, 3 males and 5 females, were enrolled, with the mean age of 54.7 years old. The most common symptom of glomangiopericytoma was ipsilateral nasal obstruction. All patients got surgical treatment, and one patient received radiation to the surgical site, whose margin of resection was positive. The mean follow-up period was 39.5 months (3-176 months). During the follow-up period, one patient was found to have a positive resection margin. CONCLUSION: The surgical outcome shows that complete initial excision is important to prevent recurrence. Furthermore, adjuvant radiation therapy may also be a reasonable option for some patients with margin involvement.

Glomangiopericytoma: The sinonasal mimic of soft tissue hemangiopericytoma

@#A 42-year old Filipino male with a 10-month history of progressive left nasal obstruction and rhinorrhea and a clinical impression of nasal polyposis underwent endoscopic sinus surgery with partial ethmoidectomy and polypectomy. We received several dark-brown, irregular, rubbery tissue fragments with an aggregate diameter of 3 cm. Histopathologic examination shows sheets of spindly tumor cells beneath the respiratory epithelial lining. These spindle cells are closely packed and arranged in short fascicles and storiform clusters surrounding hyalinized large vessels or thin-walled submucosal blood vessels. (Figures 1 and 2) There is no atypia or necrosis. Immunohistochemical studies show strong immunoreactivity to muscle specific actin, and focal reactivity to S-100. (Figure 3) Stains for CD34, caldesmon, cytokeratin, and desmin, are negative. (Figure 4) Based on these features, we diagnosed the case as glomangiopericytoma. Glomangiopericytoma is a rare tumor arising from the pericytes surrounding capillaries, and accounts for less than 0.5% of all sinonasal tumors.1 It has a very slight female preponderance, with a peak incidence during the seventh decade of life. The most common symptom is nasal obstruction, or epistaxis, with accompanying difficulty breathing, sinusitis and headache. A mass, or polyp is the most common clinical finding.2 Hematoxylin–eosin staining shows a well-delineated but unencapsulated cellular tumor underneath the normal respiratory epithelium that effaces or surrounds adjacent normal structures.2 The tumor is composed of closely packed, uniform, oval to spindle-shaped cells, in short fascicles and in storiform, whorled or palisaded patterns. The cells surround numerous branching thin-walled, blood vessels, thus the morphologic resemblance to soft tissue hemangiopericytoma/solitary fibrous tumor. However, in contrast to hemangiopericytoma, glomangiopericytoma shows diffuse reactivity to muscle actins, and non-reactivity to CD34, while hemangiopericytoma shows the reverse reactions. Desmin and caldesmon are likewise non-reactive, distinguishing the tumor from leiomyomas or leiomyosarcomas of the upper aerodigestive tract. Cytokeratin non-reactivity distinguishes it from spindle cell carcinoma. S100, although typically negative, can be focally and weakly positive in a small percentage of tumor.3 Glomangiopericytoma is categorized as a borderline low malignancy tumor with an overall survival of >90% in 5 years but which tends to recur in up to 30% of cases. Strict follow-up is thus required, especially if complete resection is not achieved.1

Diagnostic value of STAT6 immunohistochemistry in solitary fibrous tumor/meningeal hemangiopericytoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the diagnostic role of STAT6 immunohistochemistry in solitary fibrous tumors (SFT)/meningeal hemangiopericytomas (HPC).</p><p><b>METHOD</b>Evaluated the expression of STAT6, vimentin, CD34, EMA, PR, S-100, CD56, GFAP and Ki-67 in a cohort of 37 SFT/meningeal HPC, 30 meningiomas and 30 schwannomas by immunohistochemistry staining.</p><p><b>RESULTS</b>All SFT/meningeal HPC demonstrated nuclear positivity for STAT6, and the proportion of positive tumor cells ranged from 60% to 95%, with no significant difference cases.Vimentin was strongly positive in all cases. CD34, EMA and PR positivity was found in 32 cases, 1 case and 4 cases, respectively.S-100 protein, CD56 and GFAP were negative; Ki-67 labeling index was 1%-8%. However, the meningiomas and schwannomas were negative for STAT6.</p><p><b>CONCLUSIONS</b>STAT6 is a relatively specific biomarker for SFT/meningeal HPC, and may be used in the diagnosis and differential diagnosis of SFT/meningeal HPC, especially for the atypical cases, and allows the precise pathologic diagnosis of SFT/meningeal HPC.</p>

Meningeal Solitary Fibrous Tumors with Delayed Extracranial Metastasis

BACKGROUND: The term solitary fibrous tumor (SFT) is preferred over meningeal hemangiopericytoma (HPC), because NAB2-STAT6 gene fusion has been observed in both intracranial and extracranial HPCs. HPCs are now considered cellular variants of SFTs. METHODS: This study analyzes 19 patients with STAT6-confirmed SFTs, who were followed for over 11 years in a single institution. Ten patients (10/19, 56.2%) had extracranial metastases (metastatic group), while the remainder (9/19) did not (non-metastatic group). These two groups were compared clinicopathologically. RESULTS: In the metastatic group, the primary metastatic sites were the lungs (n = 6), bone (n = 4), and liver (n = 3). There was a mean lag time of 14.2 years between the diagnosis of the initial meningeal tumor to that of systemic metastasis. The median age at initial tumor onset was 37.1 years in the metastatic group and 52.5 in the non-metastatic group. The 10-year survival rates of the metastatic- and non-metastatic groups were 100% and 33%, respectively. The significant prognostic factors for poor outcomes on univariate analysis included advanced age (≥45 years) and large initial tumor size (≥5 cm). In contrast, the patients with higher tumor grade, high mitotic rate (≥5/10 high-power fields), high Ki-67 index (≥5%), and the presence of necrosis or CD34 positivity showed tendency of poor prognosis but these parameters were not statistically significant poor prognostic markers. CONCLUSIONS: Among patients with SFTs, younger patients (<45 years) experienced longer survival times and paradoxically had more frequent extracranial metastases after long latent periods than did older patients. Therefore, young patients with SFTs require careful surveillance and follow-up for early detection of systemic metastases.