Overlap of membranous nephropathy and IgA nephropathy in a patient with Kimura's disease: a case report and literature review.

Introduction: Kimura's disease (KD) is a rare chronic inflammatory disorder characterized by subcutaneous lymphoid hyperplasia with peripheral eosinophilia. Kidney involvement is reported in 15%-18% of adult patients with KD, in many cases as nephrotic syndrome. We present a case of overlapping membranous nephropathy and IgA nephropathy associated with KD. Case report: A 27-year-old man was admitted with a history of bilateral leg edema for the last 2 months and concomitant progressive increase of cervical mass and fever. Laboratory findings were as follows: peripheral leukocyte count, 10,080/mm³; eosinophils, 3,200/mm³ (31.7%); serum creatinine, 0.83 mg/dL; and eGFR: 140 mL/min per 1.73 m2. Urinalysis revealed the presence of hematuria and proteinuria and the following results: 24-h proteinuria, 12.9 g; serum albumin, 1.3 g/dL; and elevated IgE level, 750 kU/L. Serologies for hepatitis B, hepatitis C, HIV, and VDRL were all negative. Complement C3 and C4 levels were normal. No monoclonal protein was detected in blood and urine. Parasite infestation was discarded. A biopsy of the cervical lymph node revealed eosinophilic lymphoid hyperplasia, suggesting KD. A kidney biopsy revealed findings consistent with the overlapping of membranous nephropathy with IgA nephropathy. The patient was treated for KD with prednisone 1 mg/kg/d with progressive dose tapering and posterior association of methotrexate 15 mg/week. A renin-angiotensin system inhibitor was prescribed for nephrotic syndrome. The cervical mass regressed, and proteinuria achieved partial remission, with an increase in serum albumin level and normalization of eosinophils and IgE levels. Conclusion: Although uncommon, kidney involvement must be considered in patients with KD. Glomerular diseases are the most frequent form of kidney injury.

Pelvic Ewing Sarcoma: The Great Mimicker / Sarcoma de Ewing pélvico: o grande imitador

Abstract Ewing sarcoma is the most common malignant bone tumor of the pelvis in children and young adults. Even with aggressive treatment, its survival rate is amongst the poorest. Classical presentation may not be the rule. It may simulate clinically, imagiologically and histopathologically other nonmalignant entities. Therefore, its suspicion should not be overlooked. We report two cases of pelvic Ewing sarcoma: the first mimicking eosinophilic granuloma, and the second mimicking osteomyelitis. In the latter, we also report an atypical finding of its natural history: an initial response to antibiotic and anti-inflammatory treatment. In both cases, we highlight the possibility of an inconclusive percutaneous bone biopsy and the importance of immunochemistry and cytogenetics for the definitive diagnosis.

Resumo O sarcoma de Ewing é o tumor ósseo maligno da pelve mais comum em crianças e adultos jovens. Mesmo com tratamento agressivo, sua taxa de sobrevivência está entre as piores. A apresentação clássica pode não ser a regra. Ele pode simular clinicamente, imaginologicamente e histopatologicamente outras entidades não malignas. Portanto, sua suspeita não deve ser negligenciada. Relatamos dois casos de sarcoma pélvico: o primeiro imitando granuloma eosinofílico e o segundo imitando osteomielite. Neste último, também relatamos um achado atípico de sua história natural: uma resposta inicial ao antibiótico e ao tratamento anti-inflamatório. Em ambos os casos, destacamos a possibilidade de uma biópsia óssea percutânea inconclusiva e a importância da imunoquímica e da citogenética para o diagnóstico definitivo.

[Kimura's disease mimicking primary neoplasm of the parotid gland: A case report]. / Enfermedad de Kimura simulando neoplasia primaria de glándula parótida: Reporte de caso.

Background: Kimura's disease is an infrequent inflammatory disorder, of unknown etiology, with few reports outside of Asia. It presents as a nodule or tumor predominantly in the postauricular region, neck and parotid gland. It is histologically characterized by follicular hyperplasia with wellformed mantle zones, preservation of nodal architecture, prominent eosinophilic infiltrate in the germinal centers and interfollicular areas; and associated with elevated levels of IgE and peripheral eosinophilia. Clinical case: We present a case of a 23-year-old man from Mexico, he presented with a recurrent tumor in the right parotid gland, previously treated with surgical resection. Imaging studies were performed and a primary neoplasm of the salivary gland was suspected, he was treated with surgical resection. The histological diagnosis was Kimura's disease. Conclusions: Communication and divulgation of this rare inflammatory disorder expans the knowledge for the differential diagnosis of tumors of the head and neck, and salivary glands, mainly in men with peripheral eosinophilia and elevated IgE; it can sometimes simulate malignant neoplasms, leads to inadequate diagnostic and therapeutic approaches.

Introducción: la enfermedad de Kimura es un desorden inflamatorio poco frecuente, de etiología desconocida y raramente reportado fuera del continente asiático. Se presenta como un nódulo o tumor predominantemente en la región retroauricular, cervical o glándula parótida. Se caracteriza histológicamente por hiperplasia folicular con zonas del manto bien formadas, preservación de la arquitectura ganglionar, infiltrado eosinofílico prominente en los centros germinales y áreas interfoliculares; generalmente asociada a niveles elevados de IgE y eosinofilia periférica. Caso clínico: presentamos el caso de un hombre de 23 años, de origen mexicano que se presentó con un tumor recidivante a dos años de resección quirúrgica previa en glándula parótida derecha, se realizaron estudios de imagen y se sospechó de neoplasia primaria de glándula salival, fue tratado con resección quirúrgica. El diagnóstico histológico fue de enfermedad de Kimura. Conclusiones: la comunicación y difusión de este raro desorden inflamatorio amplía la base del conocimiento para el diagnóstico diferencial de tumores de cabeza y cuello, y glándulas salivales, predominantemente en hombres con eosinofilia periférica y elevación de IgE; que en ocasiones puede simular neoplasias malignas, llevando a abordajes diagnósticos y terapéuticos inadecuados.