Renal oncocytoma in a kidney transplant patient: the imaging features on contrast-enhanced ultrasonography (CEUS): a case report.

Renal oncocytoma is an infrequently reported renal neoplasm, often asymptomatic, which usually behaves as a benign entity and is identified accidentally on radiological imaging. Transplant patients under long-term immunosuppressive drugs have a high prevalence of cancers, such as skin cancers, lymphoproliferative disorders, and renal carcinomas. We present a case report of an asymptomatic renal oncocytoma in a kidney transplant recipient presenting persistent hematuria. The features of computed tomography and contrast-enhanced ultrasound (CEUS) are presented. This was the first time we used CEUS in a transplant kidney recipient presenting a renal mass, allowing the real-time visualization of contrast-enhancement patterns during all vascular phases for the differential diagnosis of renal tumors. Although the pattern of intense vascularization could mislead to an early judgment as a malignant lesion, it could help to exclude other renal lesions without inducing nephrotoxicity.

Renal oncocytoma in a kidney transplant patient: the imaging features on contrast-enhanced ultrasonography (CEUS): a case report / Oncocitoma renal em paciente transplantado: achados de imagem na ultrassonografia com contraste

Abstract Renal oncocytoma is an infrequently reported renal neoplasm, often asymptomatic, which usually behaves as a benign entity and is identified accidentally on radiological imaging. Transplant patients under long-term immunosuppressive drugs have a high prevalence of cancers, such as skin cancers, lymphoproliferative disorders, and renal carcinomas. We present a case report of an asymptomatic renal oncocytoma in a kidney transplant recipient presenting persistent hematuria. The features of computed tomography and contrast-enhanced ultrasound (CEUS) are presented. This was the first time we used CEUS in a transplant kidney recipient presenting a renal mass, allowing the real-time visualization of contrast-enhancement patterns during all vascular phases for the differential diagnosis of renal tumors. Although the pattern of intense vascularization could mislead to an early judgment as a malignant lesion, it could help to exclude other renal lesions without inducing nephrotoxicity.

Resumo O oncocitoma renal é uma neoplasia renal raramente relatada, muitas vezes assintomática, que geralmente se comporta como uma entidade benigna e é identificada acidentalmente em imagens radiológicas. Pacientes transplantados em regimes imunossupressores de longa duração apresentam alta prevalência de neoplasias tais como câncer de pele, distúrbios linfoproliferativos e carcinomas renais. Apresentamos o relato de um caso de oncocitoma renal assintomático em receptor de transplante renal com hematúria persistente. São apresentados os achados de imagens de tomografia computadorizada e ultrassonografia (US) com contraste. Foi a primeira vez que utilizamos a US com contraste em um receptor de transplante renal que apresentava massa renal, permitindo a visualização em tempo real dos padrões de realce do contraste em todas as fases vasculares para o diagnóstico diferencial dos tumores renais. Embora o padrão de vascularização intensa possa induzir uma avaliação precoce de lesão maligna, o exame ajuda a excluir outras lesões renais sem induzir nefrotoxicidade.

Screening for CLCN5 mutation in renal calcium stone formers patients.

UNLABELLED: Thirty-five patients (23 males and 12 females), age 35 +/- 13 years old, presenting either idiopathic calcium nephrolithiasis, nephrocalcinosis or mild renal failure with idiopathic calcium nephrolithiasis were selected for the analysis of low molecular weight proteinuria and the possible mutations occurrence in the chloride channel gene CLCN5. The urinary ratio of beta2-microglobulin and creatinine (beta2M/Cr) was very high in a transplanted woman with nephrocalcinosis (> 3.23 mg/mmol) and slightly high in five patients (> 0.052 or < 1.0 mg/mmol) with multiple urological manipulations. Other studied patients showed beta2M/Cr ratio at normal range (0.003-0.052 mg/mmol) without gender difference (p > 0.05). Mutation analysis of CLCN5 gene was performed in 26 patients of 35 selected (11 with idiopathic hypercalciuria; 6 men with normal calciuria; 3 with mild renal insufficiency and 6 with nephrocalcinosis) and was normal in all subjects even in those with abnormal molecular weight proteinuria. CONCLUSION: CLCN5 gene mutation is not a common cause of kidney stone disease or nephrocalcinosis in a group of Brazilian patients studied.

Screening for CLCN5 mutation in renal calcium stone formers patients

Trinta e cinco pacientes (23 homens e 12 mulheres) com idade de 35 ±13 anos apresentando nefrolitíase idiopática cálcica, nefrocalcinose ou insuficiência renal leve com nefrolitíase idiopática cálcica foram selecionados para análise de proteinúria de baixo peso molecular e a ocorrência de possíveis mutações no gene CLCN5. A razão entre a b2-microglobulina urinária e a creatinina urinária (b2M/Cr) foi muito elevada em uma mulher transplantada com nefrocalcinose ( > 3.23 mg/mmol) e levemente elevada em cinco pacientes ( > 0.052 ou < 1.0 mg/mmol) com manipulação urológica múltipla. Outros pacientes estudados mostraram uma razão b2M/Cr nos limites normais (0.003-0.052 mg/mmol) sem diferença entre os sexos (p > 0.05). A análise da mutação do gene do gene CLCN5 foi realizada em 26 pacientes dos 35 selecionados (11 com hipercalciúria idiopática; 6 homens com calciúria normal; 3 com leve insuficiência renal e 6 com nefrocalcinose) e não apresentou alteração em nenhum dos casos, mesmo naqueles com proteinúria de baixo peso molecular anormal. Conclusão: A mutação do gene do CLCN5 não é uma causa comum de calculose renal ou nefrocalcinose no grupo de pacientes brasileiros estudados.