Congenital thymoma

Thymomas are a heterogeneous group of tumors arising from the epithelium of the thymus. They are categorized by the proportion of neoplastic epithelia to lymphocytes and by the degree of cytologic atypia. Thymomas constitute 0.2-1.5% of all malignancies and nearly all occur in patients over 20 years. We reviewed the available literature and found less than 50 cases of thymoma reported in children (<18 years of age), the youngest being 4 years old, and no cases in newborns. They represent less than 1% of all mediastinal tumors in children. Due to the limited number of cases in the pediatric population, the diagnosis and treatment in this population is extremely challenging. Thymomas in all age groups may be associated with paraneoplastic syndromes, being myasthenia gravis the most common, which is associated with a worse prognosis in the pediatric population. We present the first case of a newborn infant with congenital thymoma. This case demonstrates a rare tumor in an unusual age group and emphasizes the importance of multidisciplinary teamwork in the decision-making and management of this condition.

Revisando un órgano olvidado: Evaluación del timo en PET-CT / Revisiting a Forgotten Organ: Thymus Evaluation in PET-CT

Resumen La pesquisa incidental de lesiones tímicas ha aumentado. Una adecuada aproximación a esas lesiones en la tomografía computada por emisión de positrones (PET-CT) es fundamental, pues se usa como parte de la mayoría de los procedimientos de planificación oncológica. Se han seleccionado casos representativos respecto de los aspectos más importantes de las imágenes de timo en PET-CT y cómo esa técnica puede contribuir a un diagnóstico preciso o a la planificación del tratamiento. Específicamente, presentamos una descripción general de las lesiones tímicas comunes y los imitadores de enfermedad, con énfasis en los hallazgos en PET-CT, incorporando también ejemplos de resonancia magnética (RM).

Abstract Incidental thymic lesion findings have increased. An adequate characterization of these lesions in positron emission computed tomography (PET-CT) is essential, since it is used as part of most oncological planning procedures. Representative cases have been selected regarding the most important aspects of thymus imaging in PET-CT and how this technique can contribute to an accurate diagnosis or treatment planning. Specifically, we present a general description of common thymic lesions and disease mimics, with an emphasis on PET-CT findings, also incorporating examples of magnetic resonance imaging.

Enfermedades del timo por exceso y por defecto / Thymus diseases by excess and default

El timo es un órgano cervicotorácico, impar y mediano, situado en la base del cuello y parte superior del mediastino. Junto a la médula ósea es uno de los dos órganos primarios del sistema inmune y ejerce su función en los neonatos y en los niños, fundamentalmente. Entra en regresión a partir de la pubertad, aunque algunos autores plantean que la involución puede comenzar un poco antes, cuando los principales tejidos linfoides están plenamente desarrollados. Interviene sinérgicamente con otras glándulas de secreción interna: tiroides, suprarrenal, hipófisis, para elaborar substancias necesarias para el desarrollo general del organismo. Es un órgano muy sensible a todo influjo. Como todos los órganos de la economía el timo presenta enfermedades producidas tanto por crecimiento exagerado, como por hipoplasias o atrofias. Dentro de las primeras las más comunes son la hiperplasia tímica y el timoma y, entre las últimas el síndrome de DiGeorge ha sido bien caracterizado en la literatura internacional desde la segunda mitad del siglo pasado. Sin embrago, en los últimos tiempos los inmunólogos hablan de la hipoplasia tímica como entidad que puede asociarse o no a estados de inmunodeficiencia. Se describen brevemente estas afecciones(AU)

The thymus is a cervicothoracic organ, odd and medium, located at the base of the neck and upper part of the mediastinum. Next to the bone marrow is one of the two primary organs of the immune system and exerts its function in neonates and children, fundamentally. It regresses after puberty, although some authors suggest that the involution can begin a little earlier, when the main lymphoid tissues are fully developed. It intervenes synergistically with other glands of internal secretion: thyroid, adrenal, pituitary gland, to develop substances necessary for the general development of the organism. It is a very sensitive organ to all influence. Like all the organs of the economy, the thymus presents diseases caused both by exaggerated growth, as by hypoplasias or atrophies. Among the former, the most common are thymic hyperplasia and thymoma and, among the latter, DiGeorge syndrome has been well characterized in international literature since the second half of the last century. However, in recent times immunologists speak of thymic hypoplasia as an entity that may or may not be associated with immunodeficiency states. These conditions are briefly described(AU)

Tumores del timo: Experiencia del Instituto Nacional de Cancerología de Colombia / Thymic tumors: Experience of the National Cancer Institute of Colombia

Resumen Objetivos: Los tumores del timo tienen incidencia global de 0,13 por 100.000 habitantes, pero representan un importante porcentaje de tumores del mediastino. Hay poca literatura basada en nuestra población, por esto, hacemos un aporte de nuestra experiencia en el Instituto Nacional de Cancerología (INC). Métodos: Se hizo un estudio tipo series de caso, revisando las historias clínicas de los pacientes con tumores del timo tratados en el INC entre 2006 y 2017. Resultados: Desde el 2006 al 2017 se encontraron 31 pacientes con tumores del timo tales como timoma, hiperplasia tímica, quistes tímicos y carcinomas tímicos, predominando en el género femenino y con una mediana de 62 años de edad. 2 pacientes presentaron miastenia gravis (MG). 27 fueron sometidos a timectomía por medio de esternotomía, videotoracoscopia, toracotomía, entre otros, obteniendo una supervivencia global mayor al 90% a 5 años de seguimiento. Los estadios de Masaoka I, II y III tienen mejor pronóstico que los tipos IV independientemente de la histología. Conclusiones: La timectomía es el tratamiento de primera línea en los casos resecables, incluso en los que existe compromiso de estructuras vecinas que permiten una resección quirúrgica completa. Los resultados presentados describen conductas y resultados similares a los encontrados en la literatura mundial.

Abstract Objectives: Thymic tumors have an overall incidence of 0.13 per 100,000 inhabitants, but they represent a significant percentage of mediastinal tumors. There is little literature based on our population, we make a contribution of our experience in the National Cancer Institute. Methods: We did a case series study, reviewing the clinical histories of patients with thymic tumors treated at the National Cancer Institute from 2006 to 2017. Results: From 2006 to 2017, 31 patients with thymic tumors such as thymoma, thymic hyperplasia, thymic cysts and thymic carcinomas were found, mainly in the female gender and with a median of 62 years of age. 2 patients presented Myasthenia Gravis (MG). 27 patients underwent thymectomy through sternotomy, video-thoracoscopy, thoracostomy among others, obtaining an overall survival greater than 90% at 5 years of follow-up. The stages of Masaoka I, II and III have a better prognosis than type IV regardless of the histological type. Conclusions: Thymectomy is the first-line treatment in resectable cases, even when there is a compromise of nearby structures that allow a complete surgical resection. Our results describe behaviors and results similar to those found in the world literature.

Enfermedad de Graves-Basedow e hiperplasia tímica: una asociación que no nos debe extrañar / raves-Basedow disease and thymic hyperplasia: an association that must not surprise us

RESUMEN El aumento del tamaño del timo asociado a hiperplasia tímica (HT) es frecuente en los pacientes con enfermedad de Graves-Basedow (EGB), si bien es poco habitual detectarla en la práctica clínica diaria. Presentamos el caso de una mujer de 38 años con EGB, a quien se le detectó de manera incidental un aumento del timo. La paciente no tenía síntomas compresivos locales y la tomografía computarizada demostró engrosamiento homogéneo de mediastino anterior sugestivo de HT. Durante la evolución, se evidenció reducción del tamaño tras el control de la función tiroidea con fármacos antitiroideos. La presencia de algunas características radiológicas como aumento difuso y homogéneo de la glándula, ausencia de invasión de estructuras vecinas, calcificaciones o imágenes quísticas, sugiere la presencia de una HT. En estos casos, el tratamiento del hipertiroidismo y un control expectante son actitudes razonables. Conocer esta evolución puede evitar intervenciones diagnósticas o terapéuticas innecesarias.

ABSTRACT Thymic enlargement associated with thymic hyperplasia (TH), in patients with Graves-Basedow disease (GBD) is common, although it remains largely unrecognized in routine clinical practice. We present the case of a 38 year-old woman with GBD, to whom an incidental thymic enlargement was detected. The patient did not have local compressive symptoms and the computerized tomography showed homogenous thickening of the anterior mediastinum suggestive of TH. During evolution, a reduction in size was observed after thyroid function was controlled by anti-thyroid drugs. The presence of some radiological features such as diffuse and homogeneous gland enlargement, absence of invasion of neighboring structures, calcifications or cystic images suggests the presence of TH. In these cases treatment of hyperthyroidism and expectant management are reasonable responses. Recognizing this evolution can avoid unnecessary diagnostic or therapeutic interventions.

Caracterización clínica de los pacientes miasténicos timectomizados / Clinical Characterization of Thymectomized Myasthenic Patients

Introducción: la miastenia gravis es una enfermedad crónica de la unión neuromuscular, de naturaleza autoinmune y es reconocido que la timectomía es una modalidad terapéutica efectiva en esta entidad clínica. Objetivos: realizar una caracterización clínica de los pacientes miasténicos timectomizados. Métodos: se realizó un estudio observacional descriptivo retrospectivo, en el Servicio de Neurología del Hospital Clínico Quirúrgico Hermanos Ameijeiras en el periodo comprendido de enero de 1984 a diciembre de 2014. Resultados: se reclutaron 393 pacientes, la mayoría fueron del sexo femenino y del grupo de edad de 30-39 años, predominó el grado II b (65,3 por ciento) de intensidad de la enfermedad. La hiperplasia tímica (66,9 por ciento) fue la alteración histológica del timo más común. El hipertiroidismo fue la enfermedad autoinmune más frecuente. La crisis miasténica representó la complicación posoperatoria principal y apareció esencialmente en pacientes con timoma. La mortalidad fue de 1,3 por ciento. Conclusiones: fue más común el grado II b de intensidad de la enfermedad, el tipo histológico de hiperplasia tímica y la mortalidad baja(AU)

Introduction: Myasthenia gravis is a chronic disease of the neuromuscular junction, it is autoimmune by nature and it is recognized that thymectomy is an effective therapeutic modality in this clinical entity. Objectives: Clinically characterize the myasthenic thymectomized patients. Methods: A retrospective, descriptive, observational study was conducted in the Neurology Service at Hermanos Ameijeiras Surgical Clinical Hospital from January 1984 to December 2014. Results: 393 patients were recruited; the majority was female and aged 30-39 years. 65.3 percent of them had grade II b of disease intensity. Thymic hyperplasia (66.9 percent was the most common histological alteration of the thymus. Hyperthyroidism was the most frequent autoimmune disease. The myasthenic crisis represented the main postoperative complication and it essentially showed in patients with thymoma. Mortality was 1.3 percent. Conclusions: Grade II b disease intensity was more common, the histological type of thymic hyperplasia and mortality was low(AU)

Graves' Patient with Thymic Expression of Thyrotropin Receptors and Dynamic Changes in Thymic Hyperplasia Proportional to Graves' Disease Activity

Thymic hyperplasia is frequently observed in Graves' disease. However, detectable massive enlargement of the thymus is rare, and the mechanism of its formation has remained elusive. This case showed dynamic changes in thymic hyperplasia on serial computed tomography images consistent with changes in serum thyrotropin receptor (TSH-R) antibodies and thyroid hormone levels. Furthermore, the patient's thymic tissues underwent immunohistochemical staining for TSH-R, which demonstrated the presence of thymic TSH-R. The correlation between serum TSH-R antibody levels and thymic hyperplasia sizes and the presence of TSH-R in her thymus suggest that TSH-R antibodies could have a pathogenic role in thymic hyperplasia.

Miastenia grave generalizada: reporte de un caso / Generalized-myasthenia gravis: a case report

Mujer de 17 años de edad, con diagnostico reciente de miastenia gravis, en tratamiento irregular con piridostigmina y prednisona; que acudió por presentar debilidad muscular generalizada, disfagia, diplopía y ptosis palpebral. El examen físico encontró una tiroides aumentada de tamaño. Los exámenes auxiliares mostraron T4 libre y TSH normales, pero los anticuerpos antirreceptor de acetilcolina fueron positivos. Se realizó timectomía, pero en el postoperatorio, la paciente presentó crisis miasténica con insuficiencia respiratoria, por lo que fue sometida a ventilación mecánica. Después de dos semanas, la paciente fue dada de alta sin presentar debilidad muscular, disfagia o ptosis palpebral. El tratamiento al alta fue piridostigmina. La miastenia grave es una enfermedad autoinmune que se caracteriza por debilidad muscular fluctuante. En los casos de inicio temprano (menores de 40 años), esta asociada a hiperplasia del timo y otras enfermedades autoinmunes. La timectomía es el tratamiento de elección en pacientes menores de 50 años.

A 17-year-old woman presented with generalized weakness, dysphagia, ptosis, and diplopia. Recently, she was diagnosed with myasthenia gravis, and her treatment included pyridostigmine and prednisone. Physical examination showed goiter. Thyroid hormones were normal, but the autoantibodies against the postsynaptic acetylcholine receptor were positive. She underwent thymectomy, and developed respiratory insufficiency secondary to myasthenic crisis. After two weeks, she was discharged without complaints. Her long-term treatment included pyridostigmine. Myasthenia gravis is a rare autoimmune disease. The clinical hallmark is fatigable weakness. Patients with early- onset disease (< 40 years), are more often female, have enlarged, hyperplastic thymus glands, and other organ- specific autoantibodies might be present. Thymectomy is the treatment of choice in patients with disease onset before the age of 50 years.

Clinicopathologic features of primary thymic extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the clinicopathologic features of primary thymic extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT).</p><p><b>METHODS</b>The clinical and pathologic findings were evaluated in 3 cases of biopsy confirmed thymic MALT lymphoma. The clincopathologic features, treatment and prognosis were discussed and literatures reviewed.</p><p><b>RESULTS</b>One male and two female patients presented with asymptomatic mediastinal masses with a history of Sjögren syndrome. They were aged 36, 35 and 41 years respectively, and only one patient had B symptoms. Grossly, all three tumors were encapsulated and had multiple variable-sized cysts on cut-surface. Histopathologically, the normal thymic lobular architecture was effaced by abnormal dense lymphoid infiltration. Prominent lymphoepithelial lesions were formed by centrocyte-like cells infiltrating and expanding Hassall's corpuscles and epithelial cyst lining. All cases showed apparent plasmacytic differentiation. Immunohistochemically, the tumor cells were positive for CD20, CD79a, bcl-2 and negative for CD3, CD5, cyclin D1, CD43, CD10, bcl-6, and CD23. The plasma cells showed kappa light chain restriction. Immunoglobulin heavy chain rearrangement in three cases was confirmed by PCR. All patients were at early stage and received routine chemotherapy with or without radiotherapy after surgical removal. All patients achieved complete remission with 24, 18 and 3 months follow-up, respectively.</p><p><b>CONCLUSIONS</b>Primary thymic MALT lymphoma may be a rare distinctive lymphoma. It can be diagnosed by HE and immunohistochemical study and should be differentiated from reactive lymphoid proliferation, other types of lymphoma and mediastinal thymoma.</p>

Unusual Thymic Hyperplasia Mimicking Lipomatous Tumor in an Eight-Year-Old Boy with Concomitant Pericardial Lipomatosis and Right Facial Hemihypertrophy

We report a case of thymic hyperplasia accompanied by pericardial lipomatosis and right facial hemihypertrophy in an 8-year-old boy. On imaging studies, the hyperplastic thymus had prominent curvilinear and nodular fatty areas simulating a fat-containing anterior mediastinal mass, which is an unusual finding in children. To our knowledge, this is the first report on a child with a combination of thymic hyperplasia, pericardial lipomatosis, and right facial hemihypertrophy. The radiologic findings are presented with a brief discussion.

Robot-assisted Thymectomy with the 'da Vinci' Surgical System in a Patient with Myasthenia Gravis: A case report / 대한흉부외과학회지

In the treatment of myasthenia gravis, thymectomy is generally accepted as the standard of therapy. For thymectomy, there have been various conventional open approaches including sternal splitting, but recently minimally invasive approaches have been increasingly applied. A 28-year-old man presenting with weakness of both hands and fatigability was diagnosed as having myasthenia gravis with thymic hyperplasia. He underwent a robot-assisted thymectomy with the 'da Vinci' surgical system. Through the right thoracic cavity, two thirds of the thymic gland was dissected, and the remainder was resected through the left; these procedures took, respectively, 1 hour and 30 minutes. The patient was discharged on the 8th postoperative day without complications. The minimally invasive approach with the 'da Vinci' surgical system is emerging as a popular choice and various advantages have been reported. Here we report the first successful case of robot-assisted thymectomy.

A Case of Cystic Pneumomediastinum with Thymic Hyperplasia in a Newborn / 소아알레르기및호흡기학회지

Spontaneous pneumomediastinum in a term newborn without mechanical ventilation or underlying lung disease is rare. We present a case of a newborn baby who developed respiratory distress after birth and cystic pneumomediastinum which improved spontaneously with thymic hyperplasia as demonstrated on chest radiography, CT and MRI. The combination of cystic pneumomediastinum and thymic hyperplasia in a newborn has not been reported, thus far.

Case of generalised myasthenia gravis with membranous nephropathy.

We report a 40-year old woman with bilateral partial ptosis, complete external ophthalmoplegia, and weakness and fatiguability of upper limbs. She was on treatment for hypertension for 5 months at the time of admission. She was found to have generalised myasthenia gravis and membranous nephropathy with end-stage renal disease. Her symptoms and signs improved within 2 months on treatment with neostigmine and prednisolone. It is postulated that either thymic hyperplasia or the subclinical stage of a thymoma may be the underlying aetiological factor in this patient.

Miastenia gravis / Myasthenia gravis

Caso clínico: Paciente masculino de 66 años, originario de Guatemala, con dificultad respiratoria de 3 días de evolución, asociada a fatiga, tos y expectoración ocasional, no asociada a fiebre...

Myasthenia gravis in iranian children

This study was undertaken to evaluate the clinical spectrum of myasthenia gravis in children and determine factors that help the clinician in his/her diagnosis and management. A retrospective review was performed on all pediatric patients suffering from myasthenia gravis [M.G] admitted in the department of pediatric neurology of the Mofid Hospital of the Shaheed Beheshti University, between 1994 and 2002. Of the thirty-two children with M.G. enrolled in our study, seven were suffering from the congenital type while the remaining [25 cases] had the juvenile M.G. Initial symptoms of congenital M.G were ptosis [7/7], limitation of eye movement [2/7] and mild generalized weakness [6/7]. Although the Tensilon test was positive in 85% of congenital M.G cases, no myasthenia crisis or spontaneous remission was observed in any of them. In children with juvenile M.G, the age of presentation was 1.2 to 12.5 years, mean age 5.7 +/- 4.2 years [15 girls and 10 boys]. The most common presenting symptoms in juvenile group were ptosis in 96% and generalized weakness in 76%. Eight of them [32%] had had at least one myasthenia crisis. EMG was diagnostic in 83% and the tensilon test was positive in 84%. One patient had hyperthyroidism and had already been diagnosed with hypothyroidism; two of them were epileptics. Eight patients underwent thymectomy microscopically; in specimens examined, five [62%] showed thymic follicular hyperplasia while in remaining three results were normal. One patient [12.5%] recovered completely after thymectomy with no need for medication during the follow up. Four patients [50%] showed relative improvement and in three cases [37%] improvement was negligible. The results showed a female to male ratio of 1.5/1 which was correlated to adult M.G. The most common presenting symptoms consisted of ophtalmoplegia, with bilateral ptosis being the most significant. Although this study revealed that thymectomy lacks any remarkable prognostic influence, all patients had thymectomy within two years of disease onset. Some reports have indicated positive results if surgery was performed within two years of onset of disease

Tratamiento quirúrgico de la miastenia gravis / Surgical treatment of myasthenia gravis

Antecedentes: Los avances en el estudio y tratamiento de la miastenia gravis (MG) han mejorado sustancialmente su pronóstico. La timectomía es considerada uno de los pilares terapéuticos en la MG generalizada. Objetivos: Presentar la experiencia de los últimos 30 años en el tratamiento clínico y quirúrgico de pacientes con MG. Lugar de aplicación: Centro Municipal de referencia de la Ciudad de Buenos Aires. Hospital Ramos Mejía. Material y Métodos: Desde marzo de 1974 hasta el mismo mes de 2004 se estudiaron 328 pacientes, con diagnóstico de MG. Se agruparon de acuerdo a la clasificación de Osserman. Se indicó la timectomía en 112 enfermos con cuadro clínico de MG generalizada leve a moderada (II A de Osserman) y aquellos con timomas. Las vías de abordaje fueron: 15 cervicotomías, 41 transsesternales verticales totales, 51 esternales verticales parciales, 3 esternales transversales y 2 toracotomías posterolaterales. La evolución clínica, fue clasificada de acuerdo a una escala convencional. Los datos obtenidos fueron procesados mediante los tests de T de Student y de Kruskall-Wellis. Resultados: Se observó una tendencia bimodal en las edades de comienzo de la MG; 65,5 por ciento eran mujeres. Se expone la efectividad de los distintos procedimientos diagnósticos. Se obtuvieron mejores resultados en los timectomizados que en los que recibieron sólo tratamiento médico; también en los menores de 35 años, pertenecientes al grupo IIa y operados antes de los dos años de comienzo de los síntomas; 4 pacientes fueron reintervenidos por persistencia de la sintomatología clínica asociada a la visualización de restos tímicos en las imágenes. Los 4 correspondían a hiperplasias tímicas y habían sido abordados por cervicotomías puras. Se reoperaron por vía transesternal vertical total, efectuándose vaciamientos mediastinales anteriores. Se describen los diagnósticos histopatológicos, 22 por ciento eran timomas. Una enferma falleció en el post operatorio inmediato. Conclusion...

Thymus CT scan and thymoma associated antibodies in myasthenia gravis with thymoma / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the clinical significance of the serum anti-titin, anti-ryanodine receptor (RyR) antibody level and thymus CT scan in the diagnosis of myasthenia gravis with thymoma.</p><p><b>METHODS</b>Totally 32 patients with myasthenia gravis who had received thymectomy were included in the study. Abnormalities were shown under CT scan of thymus in all these patients. The relationships were studied among the pathological diagnosis, CT findings, and serum level of thymoma associated antibodies: anti-titin and anti-RyR antibodies.</p><p><b>RESULTS</b>The pathological diagnosis of thymoma was made in 21 patients and thymus hyperplasia in 11 patients after operation. The sensitivity of CT scan in the diagnosis of thymomas was 90.5%, the specificity of serum thymoma associated antibodies in the diagnosis of thymoma was 100%.</p><p><b>CONCLUSION</b>The thymoma-associated antibodies test is helpful in the differential diagnosis of thymomas and thymus hyperplasia; when combined with CT scan, it may achieve high sensitivity in the diagnosis of the thymoma.</p>