[Diagnostic significance of C4d in membranous nephropathy]. / Importancia diagnóstica del C4d en la nefropatía membranosa.

INTRODUCTION: Membranous nephropathy (MN) is the most common cause of primary nephrotic syndrome in adults (20-30%). Light microscopy shows thickening of glomerular basement membrane with appearance of spikes. These histological findings are not evident in early forms, in which case the granular deposition pattern of IgG and/or C3 in the basement membrane by immunofluorescence (IF) constitutes the diagnostic tool that allows to differentiate it from minimal change disease (MCD). Complement system plays a key role in the pathophysiology of MN. C4d is a degradation product and a marker of the complement system activation. C4d labelling by immunohistochemical (HI) technique can help in the differential diagnosis between both glomerulopathies NM and MCD when the material for IF is insufficient and light microscopy is normal. Our objective was to explore the discrimination power of C4d to differentiate between MN and MCD in renal biopsy material. METHODS: Paraffin-embedded samples were recovered from renal biopsies with a diagnosis of MN and MCD performed between 1/1/2008 and 4/1/2019. IH staining was performed by immunoperoxidase technique using a rabbit anti-human C4d polyclonal antibody. RESULTS: In all cases with MN (n = 27, 15 males) with a median age of 63 (range: 18-87) years, C4d deposits were detected. In 21 cases with MCD (12 males) with a median age of 51 (range: 18-87) years, the C4d marking was negative in every samples. CONCLUSION: The results indicate that the marking of the renal biopsy with C4d is a useful tool for the differential diagnosis between NM and MCD.

Introducción: La nefropatía membranosa (NM) es la causa más frecuente de síndrome nefrótico primario en adultos (20-30%). En la microscopia óptica se observa engrosamiento de membrana basal glomerular con aparición de espigas. Estos hallazgos histológicos no son evidentes en formas tempranas, en cuyo caso el patrón de depósito granular de IgG y/o C3 en la membrana basal por inmunofluorescencia (IF) permite diferenciarla de enfermedad por cambios mínimos (ECM). El sistema del complemento juega un papel central en la fisiopatología de la NM. C4d es producto de degradación y un marcador de la activación del complemento. La marcación con C4d en muestras de biopsias renales, por técnica de inmunohistoquímica (IH) puede colaborar en el diagnóstico diferencial entre ambas glomerulopatías. Nuestro objetivo fue explorar el poder de discriminación del C4d para diferenciar NM de ECM en material de biopsias renales. Métodos: Se recuperaron muestras en parafina de biopsias renales con diagnóstico de NM y ECM realizados entre 1/1/2008 y 1/4/2019. Se realizaron tinciones de IH por técnica de inmunoperoxidasa con C4d usando un anticuerpo policlonal antihumano de conejo. Resultados: En todos los casos con NM (n = 27, 15 hombres) con mediana de edad de 63 (rango: 18-86) años se detectaron depósitos de C4d. En los 21 casos con ECM (12 hombres) con mediana de edad de 51 (rango: 18-87) años la marcación de C4d fue negativa. Conclusión: Los resultados indican que la marcación de la biopsia renal con C4d es una herramienta útil para el diagnóstico diferencial entre NM y ECM.

Proteinosis alveolar pulmonar / Pulmonary alveolar proteinosis

Resumen La proteinosis alveolar pulmonar (PAP) es una enfermedad pulmonar difusa, infrecuente, secundaria a una alteración en la homeostasis del surfactante. Se presenta el caso de una mujer de 69 años que ingresó a sala de internación por disnea progresiva hasta clase funcional III, de tres meses de evolución, asociada a tos no productiva. Se constató insuficiencia respiratoria tipo I. Como hallazgos en tomografía de tórax se evidenció engrosamiento del intersticio pulmonar intra e interlobulillar, opacidades en vidrio esmerilado y áreas con tendencia a la consolidación bilateral. Se realizó biopsia pulmonar con diagnóstico histológico de PAP y se efectuó tratamiento con lavado pulmonar total, logrando mejoría clínica. Se destaca la necesidad de tener presente diagnósticos diferenciales de insuficiencia respiratoria e infiltrados pulmonares en el contexto de la pandemia por COVID-19, incluidas las entidades muy poco prevalentes como lo es la PAP.

Abstract Pulmonary alveolar proteinosis (PAP) is a rare, diffuse pulmonary disease due to abnormal surfactant homeostasis. We present the case of a 69-year-old woman who was admitted to the hospital for progressive dyspnea with marked limitation in activity, and non-productive cough, of three months of evolution. Type I respiratory failure was confirmed. Chest tomography findings were interlobular and intralobular septal thickening, ground glass opacities and bilateral consolidation. Histological diagnosis was made and whole-lung lavage was performed with clinical improvement. We highlight the need to keep in mind differential diagnoses of respiratory failure and pulmonary infiltrates during COVID-19 pandemic, even rare entities such as PAP.

[Pulmonary alveolar proteinosis]. / Proteinosis alveolar pulmonar.

Pulmonary alveolar proteinosis (PAP) is a rare, diffuse pulmonary disease due to abnormal surfactant homeostasis. We present the case of a 69-year-old woman who was admitted to the hospital for progressive dyspnea with marked limitation in activity, and non-productive cough, of three months of evolution. Type I respiratory failure was confirmed. Chest tomography findings were interlobular and intralobular septal thickening, ground glass opacities and bilateral consolidation. Histological diagnosis was made and whole-lung lavage was performed with clinical improvement. We highlight the need to keep in mind differential diagnoses of respiratory failure and pulmonary infiltrates during COVID-19 pandemic, even rare entities such as PAP.

La proteinosis alveolar pulmonar (PAP) es una enfermedad pulmonar difusa, infrecuente, secundaria a una alteración en la homeostasis del surfactante. Se presenta el caso de una mujer de 69 años que ingresó a sala de internación por disnea progresiva hasta clase funcional III, de tres meses de evolución, asociada a tos no productiva. Se constató insuficiencia respiratoria tipo I. Como hallazgos en tomografía de tórax se evidenció engrosamiento del intersticio pulmonar intra e interlobulillar, opacidades en vidrio esmerilado y áreas con tendencia a la consolidación bilateral. Se realizó biopsia pulmonar con diagnóstico histológico de PAP y se efectuó tratamiento con lavado pulmonar total, logrando mejoría clínica. Se destaca la necesidad de tener presente diagnósticos diferenciales de insuficiencia respiratoria e infiltrados pulmonares en el contexto de la pandemia por COVID-19, incluidas las entidades muy poco prevalentes como lo es la PAP.

[Relation between severity of atherosclerosis and progression of renal disease in nephrectomized patients]. / Relación entre gravedad de arteriosclerosis y progresión de enfermedad renal en pacientes nefrectomizados.

Radical nephrectomy is associated with a progressive decline in renal function. Clinical parameters in post-nephrectomy insufficiency were described but the impact of histopathologic vascular findings in the non-neoplastic kidney of nephrectomy specimen, has been poorly studied. Our aim was to evaluate whether the severity of atherosclerosis in non-neoplastic renal tissue predicts the evolution of glomerular filtration rate in patients undergoing total nephrectomy. Thirty-one non-donor patients with unilateral radical nephrectomy were included. Average age was 68.5 ± 11.8 years, 80% had a history of hypertension, 64% overweight and 51% were smokers. The glomerular filtration rate was estimated preoperatively, postoperatively and at 6, 12 and 24 months after surgery. Arteriolosclerosis was scored based on degree of narrowing of the vascular lumen (stage 0: no vascular narrowing; stage 1: less than 25%; stage 2: 25-50%; stage 3: more than 50%). Ten patients in stage 0 had higher basal glomerular filtration rate (75 ± 13 ml/min/1.73 m2) than eight patients in stage 2 or 3 (55 ± 22 ml/min/1.73 m2) (p 0.0886). At the last postoperative evaluation, the glomerular filtration rate was 60 ± 13 ml/min/1.73 m2 (stage 0) and 39 ± 11 ml/min/1.73 m2 (stage 2 or 3) (p = 0.05). The decrease in glomerular filtration rate was higher in patients with more severe degrees of atherosclerosis but the difference was not statistically significant. The histological evaluation of the severity of arteriosclerosis in the whole kidney allows the identification of patients with a greater risk of decreased glomerular filtration rate after a post radical nephrectomy.

Relación entre gravedad de arteriosclerosis y progresión de enfermedad renal en pacientes nefrectomizados / Relation between severity of atherosclerosis and progression of renal disease in nephrectomized patients

Nefrectomía radical se asocia a disminución progresiva de función renal. Los parámetros en insuficiencia renal post-nefrectomía están identificados, no así la importancia de la histopatología vascular en la pieza de nefrectomía. Nuestro objetivo fue evaluar si la gravedad de la aterosclerosis en tejido renal no neoplásico puede predecir la evolución del filtrado glomerular en pacientes con nefrectomía total. Se incluyeron 31 pacientes con nefrectomía radical unilateral, no donantes. Edad promedio 68.5 ± 11.8 años, 80% tenían antecedentes de hipertensión, 64% sobrepeso, 51% fumadores. Se estimó tasa de filtración glomerular preoperatoria, postoperatoria y a 6, 12 y 24 meses de cirugía. Se determinó grado de arteriolosclerosis según porcentaje de estrechamiento de luz vascular (grado 0: sin estrechamiento vascular; grado 1: menos del 25%; grado 2: 25-50%; grado 3: más del 50%). Los 10 pacientes con arteriolosclerosis grado 0 tuvieron mayor tasa de filtración glomerular basal (75 ± 13 ml/min/1.73 m²) que los 8 con grado 2 y 3 (55 ± 22 ml/min/1.73 m2) (p 0.0886). En la última evaluación, la tasa de filtrado glomerular fue 60 ± 13 ml/min/1.73 m² (grado 0) y 39 ± 11 ml/min/1.73 m² (grados 2 y 3) (p = 0.05). La disminución del filtrado glomerular fue mayor en grados más graves de ateroesclerosis (sin significación estadística). El análisis histológico de piezas quirúrgicas de nefrectomía permitiría identificar aquellos con mayor riesgo de progresión de enfermedad renal según gravedad de las lesiones vasculares ateroscleróticas.

Radical nephrectomy is associated with a progressive decline in renal function. Clinical parameters in post-nephrectomy insufficiency were described but the impact of histopathologic vascular findings in the non-neoplastic kidney of nephrectomy specimen, has been poorly studied. Our aim was to evaluate whether the severity of atherosclerosis in non-neoplastic renal tissue predicts the evolution of glomerular filtration rate in patients undergoing total nephrectomy. Thirty-one non-donor patients with unilateral radical nephrectomy were included. Average age was 68.5 ± 11.8 years, 80% had a history of hypertension, 64% overweight and 51% were smokers. The glomerular filtration rate was estimated preoperatively, postoperatively and at 6, 12 and 24 months after surgery. Arteriolosclerosis was scored based on degree of narrowing of the vascular lumen (stage 0: no vascular narrowing; stage 1: less than 25%; stage 2: 25-50%; stage 3: more than 50%). Ten patients in stage 0 had higher basal glomerular filtration rate (75 ± 13 ml/min/1.73 m²) than eight patients in stage 2 or 3 (55 ± 22 ml/min/1.73 m²) (p 0.0886). At the last postoperative evaluation, the glomerular filtration rate was 60 ± 13 ml/min/1.73 m² (stage 0) and 39 ± 11 ml/min/1.73 m² (stage 2 or 3) (p = 0.05). The decrease in glomerular filtration rate was higher in patients with more severe degrees of atherosclerosis but the difference was not statistically significant. The histological evaluation of the severity of arteriosclerosis in the whole kidney allows the identification of patients with a greater risk of decreased glomerular filtration rate after a post radical nephrectomy.

[Clinical manifestations of organizing pneumonia]. / Manifestaciones clínicas de la neumonía en organización.

Organizing pneumonia is a clinical entity asociated with nonspecific symptoms and radiological findings and abnormalities in pulmonary function tests. It is defined by the characteristic histopathological pattern: filling of alveoli and respiratory bronchioles by plugs of granulation tissue. It can be idiopathic (COP) or secondary to other causes (SOP). It is an unusual finding and the clinical and radiographic findings are nonspecific. For specific diagnosis an invasive procedure has to be done, but often empirical treatment is started when there's a clinical suspicion. We describe the clinical characteristics of 13 patients with histological diagnosis of organizing pneumonia. Data was obtained from their medical records. The median age was 76 years and the median time to diagnosis from the onset of symptoms was 31 days. In 10 cases the diagnosis was made by transbronchial biopsy. 8 patients required hospitalization, 4 of them received high doses of steroids and 3 required ventilatory support. One patient died from a cause attributable to this entity and 5 relapsed. Dyspnea, cough and fever were the most frequent symptoms. Most patients had more than one tomographic pattern being the most common ground glass opacities and alveolar consolidation. Nine patients were diagnosed with COP and 4 with SOP. The most frequent underlying cause of SOP was drug toxicity. The clinical characteristics of the reported cases are consistent with previously published series. As an interesting feature, there was a group of patients that needed high doses of steroids and ventilatory support.

Manifestaciones clínicas de la neumonía en organización / Clinical manifestations of organizing pneumonia

La neumonía en organización es una entidad clínica asociada a síntomas y hallazgos radiológicos inespecíficos y anomalías en las pruebas de función pulmonar. El patrón histopatológico característico se define por tapones intra-alveolares de tejido de granulación. Puede presentarse sin una etiología determinada -neumonía en organización criptogénica (COP, cryptogenic organizing pneumonia)- o en otra condición clínica -neumonía en organización secundaria (SOP: secondary organizing pneumonia). Es poco frecuente y las manifestaciones clínico-radiológicas son poco específicas. Para su confirmación se requieren procedimientos invasivos, siendo habitual el tratamiento empírico con esteroides sistémicos ante la sospecha clínica. Se presentan 13 casos con diagnóstico histológico de neumonía en organización describiendo las características clínicas. La mediana de edad fue 76 años y la de tiempo al diagnóstico desde el inicio de los síntomas: 31 días. En 10 casos el diagnóstico fue por biopsia transbronquial (BTB). Ocho pacientes requirieron internación, 4 de ellos recibieron pulsos de esteroides y soporte ventilatorio. Uno falleció por una causa atribuible a la entidad y 5 presentaron recaídas. Disnea, tos y fiebre fueron los síntomas más frecuentes. La mayoría presentó más de un patrón tomográfico, siendo los más habituales vidrio esmerilado y consolidación alveolar. En 9 se realizó el diagnóstico de COP y en 4 de SOP. La causa secundaria en todos los casos fue toxicidad por drogas. Las características clínicas de los casos comunicados son consistentes con las series previamente publicadas. Cabe destacar la necesidad de tratamiento con dosis altas de esteroides y soporte ventilatorio en un grupo de pacientes.

Organizing pneumonia is a clinical entity asociated with nonspecific symptoms and radiological findings and abnormalities in pulmonary function tests. It is defined by the characteristic histopathological pattern: filling of alveoli and respiratory bronchioles by plugs of granulation tissue. It can be idiopathic (COP) or secondary to other causes (SOP). It is an unusual finding and the clinical and radiographic findings are nonspecific. For specific diagnosis an invasive procedure has to be done, but often empirical treatment is started when there’s a clinical suspicion. We describe the clinical characteristics of 13 patients with histological diagnosis of organizing pneumonia. Data was obtained from their medical records. The median age was 76 years and the median time to diagnosis from the onset of symptoms was 31 days. In 10 cases the diagnosis was made by transbronchial biopsy. 8 patients required hospitalization, 4 of them received high doses of steroids and 3 required ventilatory support. One patient died from a cause attributable to this entity and 5 relapsed. Dyspnea, cough and fever were the most frequent symptoms. Most patients had more than one tomographic pattern being the most common ground glass opacities and alveolar consolidation. Nine patients were diagnosed with COP and 4 with SOP. The most frequent underlying cause of SOP was drug toxicity. The clinical characteristics of the reported cases are consistent with previously published series. As an interesting feature, there was a group of patients that needed high doses of steroids and ventilatory support.

Long-term Outcome of Lupus Nephritis Class II in Argentine Patients: An Open Retrospective Analysis.

BACKGROUND: There is controversy in medical literature over the outcome of patients with lupus nephritis (LN) class II. The aim of this study was to explore the risk of histological transformation (HT) and possible factors related to negative response to treatment in patients with mesangial LN class II. METHODS: A retrospective and multicenter study was carried out that includes patients who had received a diagnosis of LN class II on their first renal biopsy. Creatinine, urine sediment, and proteinuria were recorded at the time of the first biopsy, 6 months, and 1, 2, and 5 years after the first biopsy. Response to treatment, HT, and long-term outcome were evaluated. RESULTS: Forty-one patients were included. The manifestation at first biopsy was proteinuria greater than 0.5 g/d in 28 patients (68.29%; 8 [28.57%] of 28 patients had nephrotic syndrome), hematuria in 18 patients (43.90%), and deterioration of renal function in 3 patients (7.31%). During the follow-up (median, 8 years; range, 1-35 years), a new biopsy was performed in 18 patients (43.90%), and in 17 patients (17/18 [94.44%]), there was HT. Median time at rebiopsy was 32 months (range, 11-305 months). Of the 18 patients who had a second biopsy, 10 (55.55%) were on hydroxychloroquine versus 100% (19/19) of patients who did not undergo the procedure (P = 0.001). A year after the first renal biopsy, there are data available from 34 patients; of them, 24 patients (70.58%) had achieved response, and 10 patients (29.41%) had no response (NR) (missing data in 7). A higher 24-hour urinary protein at 6 months was predictor of worse outcome at 1 year, with statistical significance difference for the nonresponder group (median proteinuria, 2.3 g/d [range, 0-4.7 g/d]) compared with responders (median proteinuria, 0.28 g/d [range, 0-1.7 g/d]) (P = 0.0133).In the long-term follow-up (5 years), HT was the main cause of unfavorable outcome and was measured in 78.57% of patients (11/14 patients). CONCLUSIONS: This series shows a high rate of HT in long-term follow-up. Proteinuria at 6 months made it possible to set aside patients who will have an unfavorable outcome in the long term and who will thus benefit from a more aggressive treatment. The results suggest that hydroxychloroquine had a nephroprotective effect.

[Thymic neuroendocrine carcinoma with Pompe's disease of the adult]. / Carcinoma neuroendocrino de timo con enfermedad de Pompe del adulto.

Pompe disease (glycogenosis type II) is an inherited autosomal recessive lysosomal storage disease caused by a deficiency of acid alpha-glucosidase. Thymic neuroendocrine tumors, are primary thymic neoplasms with neuroendocrine differentiation that generally present as a mass within the anterior mediastinum. Both diseases are considered rare. To our knowledge the co-existence of Pompe disease and thymic neuroendocrine tumor in the same patient has not been previously reported. We could not find biological plausibility between both diseases. Further studies are needed to confirm the finding and to further increase our understanding of this association. Clinical data from epidemiological studies, case reports, case series and small formal open or controlled clinical trials may define both clinical plausibility and causality between the two conditions.

Carcinoma neuroendocrino de timo con enfermedad de pompe del adulto / Thymic neuroendocrine carcinoma with Pompe's disease of the adult

La enfermedad de Pompe (glucogenosis tipo II) es una enfermedad de depósito lisosomal, autosómica recesiva causada por una deficiencia de ácido alfa-glucosidasa. Los tumores neuroendocrinos tímicos son neoplasias primarias con diferenciación neuroendocrina que generalmente se presentan como una masa en el mediastino anterior. Ambas enfermedades se consideran raras en sí mismas. En nuestro conocimiento, la enfermedad de Pompe y un tumor neuroendocrino del timo en el mismo paciente no ha sido antes comunicada. No pudimos encontrar la plausibilidad biológica entre ambas enfermedades. Se necesitan más estudios para confirmar el hallazgo y para aumentar aún más nuestra comprensión de esta asociación. Los datos clínicos de los estudios epidemiológicos, los informes de casos, las series de casos y los pequeños ensayos clínicos abiertos o controlados pueden definir tanto la plausibilidad clínica como la causalidad entre las dos enfermedades.

Pompe disease (glycogenosis type II) is an inherited autosomal recessive lysosomal storage disease caused by a deficiency of acid alpha-glucosidase. Thymic neuroendocrine tumors, are primary thymic neoplasms with neuroendocrine differentiation that generally present as a mass within the anterior mediastinum. Both diseases are considered rare. To our knowledge the co-existence of Pompe disease and thymic neuroendocrine tumor in the same patient has not been previously reported. We could not find biological plausibility between both diseases. Further studies are needed to confirm the finding and to further increase our understanding of this association. Clinical data from epidemiological studies, case reports, case series and small formal open or controlled clinical trials may define both clinical plausibility and causality between the two conditions.

Liquen escleroso genitaly extragenital: a propósito de 4 casos / Genital and extragenital lichen sclerosus: report of 4 cases

El liquen escleroso (LE) es una enfermedad mucocutánea inflamatoria crónica de etiología desconocida. Se lo ha vinculado con diversos factores inmunológicos, genéticos, hormonales, infecciosos y traumáticos. Se presenta generalmente en mujeres entre la cuarta y quinta década de la vida y su localización habitual es la genital. Las formas extragenitales son poco frecuentes y asientan en tronco, cuello y extremidades. Debido a que los síntomas que provoca en el área genital, como el prurito, dispareunia, dolor y disuria alteran la calidad de vida del paciente, es fundamental realizar un diagnóstico en forma temprana y el tratamiento adecuado. Presentamos cuatro casos de LE genital y extragenital.

Lichen sclerosus is a chronic inflammatory mucocutaneous disease of unknown aetiology. It has been linked to various immunological, genetic, hormonal, infectious and traumatic factors. It usually appears in women between fourth and fifth decade of life and usual location is genital area. Extragenital forms are rare and located on trunk, neck and extremities. Because the symptoms affecting genital area, such as itch, dyspareunia, pain and dysuria, may cause a high impact on the quality of life of patients, early diagnosis and appropiate treatment are essential. Four cases of genital and extragenital lichen sclerosus are reported.

[Intrathoracic schwannoma]. / Schwannoma intratorácico.

The schwannoma (neurilemmoma) is a slow-growing benign tumor originating from Schwann sheath whose location in the chest cavity is exceptional. It is generally asymptomatic and is discovered incidentally but can cause symptoms when the lesion grows or invade underlying structures. Its importance lies in the possibility of confusion with malignant tumors. We present a patient who complains of chest pain caused by a prolonged course schwannoma. The tomographic image is suggestive of extrapulmonary tumor, so the schwannoma in this location should be considered in the differential diagnosis of metastatic or primary pleural tumors such as lipoma, solitary fibrous tumor and mesothelioma.

Schwannoma intratorácico / Intrathoracic schwannoma

El schwannoma (neurilemoma) es un tumor benigno de lento crecimiento originado en la vaina de Schwann, cuya localización en la cavidad torácica es excepcional. En general es asintomático y se descubre en forma incidental, aunque puede ocasionar síntomas cuando la lesión crece o invade estructuras subyacentes. Su importancia radica en la posibilidad de confusión con tumores malignos. Presentamos una paciente con dolor torácico de evolución prolongada causado por un schwannoma. La imagen tomográfica es sugestiva de tumor extrapulmonar, por ello el schwannoma en esta localización debe ser considerado en el diagnóstico diferencial de tumores pleurales metastásicos o primarios como el lipoma, el tumor fibroso solitario y el mesotelioma.

The schwannoma (neurilemmoma) is a slow-growing benign tumor originating from Schwann sheath whose location in the chest cavity is exceptional. It is generally asymptomatic and is discovered incidentally but can cause symptoms when the lesion grows or invade underlying structures. Its importance lies in the possibility of confusion with malignant tumors. We present a patient who complains of chest pain caused by a prolonged course schwannoma. The tomographic image is suggestive of extrapulmonary tumor, so the schwannoma in this location should be considered in the differential diagnosis of metastatic or primary pleural tumors such as lipoma, solitary fibrous tumor and mesothelioma.

Schwannoma intratorácico / Intrathoracic schwannoma

El schwannoma (neurilemoma) es un tumor benigno de lento crecimiento originado en la vaina de Schwann, cuya localización en la cavidad torácica es excepcional. En general es asintomático y se descubre en forma incidental, aunque puede ocasionar síntomas cuando la lesión crece o invade estructuras subyacentes. Su importancia radica en la posibilidad de confusión con tumores malignos. Presentamos una paciente con dolor torácico de evolución prolongada causado por un schwannoma. La imagen tomográfica es sugestiva de tumor extrapulmonar, por ello el schwannoma en esta localización debe ser considerado en el diagnóstico diferencial de tumores pleurales metastásicos o primarios como el lipoma, el tumor fibroso solitario y el mesotelioma.(AU)

The schwannoma (neurilemmoma) is a slow-growing benign tumor originating from Schwann sheath whose location in the chest cavity is exceptional. It is generally asymptomatic and is discovered incidentally but can cause symptoms when the lesion grows or invade underlying structures. Its importance lies in the possibility of confusion with malignant tumors. We present a patient who complains of chest pain caused by a prolonged course schwannoma. The tomographic image is suggestive of extrapulmonary tumor, so the schwannoma in this location should be considered in the differential diagnosis of metastatic or primary pleural tumors such as lipoma, solitary fibrous tumor and mesothelioma.(AU)