einstein. 2006; 4(1):25-26 25 Renal angiomyolipoma rupture: Case report Renal angiomyolipoma rupture: Case report Rotura de angiomiolipoma: Relato de caso Antonio Cardoso Pinto 1 , Rodrigo Souza Madeira Campos 2 , Daniel Alcantara Pereira 3 , Gilberto Carlos Gomes 4 , Francisco Cesar Carnevale 5 , Adriano Francisco Cardoso Pinto 6 ABSTRACT Generally benign, renal angiomyolipomas are neoplasms composed of mature adipose tissue, smooth muscle, and thick-walled blood vessels. Although asymptomatic, massive retroperitoneal hemorrhage from angiomyolipomas accompanied by hypovolemic shock has been found in up to 10% of patients, usually those with large tumors. We report the case of a 33-year-old woman with spontaneous rupture of an angiomyolipoma, who was initially treated with embolization of the lesion in order to stabilize her clinical condition, and later submitted to a partial nephrectomy. Keywords: Angiomyolipoma/surgery; Rupture; Hemorrhage; Kidney, neoplasms; Case reports [Publication type] RESUMO Os angiomiolipomas são lesões geralmente benignas. Caracterizam- se pela presença de tecido adiposo maduro, músculo liso e vasos sangüíneos com parede espessada. Os angiomiolipomas são lesões assintomáticas, porém em 10% dos casos, geralmente em tumores maiores, pode ocorrer sangramento intenso, acompanhado de choque hipovolêmico. Relata-se o caso de uma mulher de 33 anos, com rotura espontânea de um angiomiolipoma, tratada inicialmente por embolização da lesão, que estabilizou o quadro clínico da paciente, sendo posteriormente realizada nefrectomia parcial. Descritores: Angiomiolipoma/cirurgia; Ruptura; Hemorragia; Neoplasias renais; Relatos de casos [Tipo de publicação] INTRODUCTION Angiomyolipomas (AML) are generally benign lesions (1- 2) , although the epithelioid angiomyolipoma, a subtype that occurs in about 3% of cases, can have an aggressive behavior. This tumor is characterized by mature adipose tissue, smooth muscle, and thick-walled blood vessels (3-4) . The true nature of these lesions is unclear, but they are usually classified as hamartomas. Thirty-three percent of patients with AML have tuberous sclerosis (TS), a dominant autosomal disease characterized by mental retardation, epilepsy, and sebaceous adenomas; more than 80% of patients with tuberous sclerosis have AML (1) . CASE REPORT We report a case of a 33-year-old woman at our institution who presented with a history of intense abdominal pain in the left flank, associated with nausea. Initially interpreted as renal colic, an ultrasound of the urinary tract identified a cystic lesion in the upper pole of the left kidney, leading to a hypothesis of a renal abscess. The patient’s hemoglobin was 11.0 g/dL. A computed tomography of the abdomen revealed a solid 80.1 mm diameter solid nodule, compatible with AML of the upper pole of the left kidney, with signs of recent bleeding (figure 1). The patient was hospitalized for observation and had a reduction in her hemoglobin to 8.0 g/dL within 4 hours. She was submitted to renal arteriography that showed contrast leakage in the upper pole. Embolization of the upper pole of the left kidney was performed, and her clinical picture stabilized (figure 2) and progressed with no complications. On day 25 post-embolization, the patient underwent an upper left polar nephrectomy, and the pathological report confirmed AML with a Study carried out at Hospital São Camilo – Pompéia, São Paulo (SP), Brazil. 1 Ph.D., Faculdade de Ciências Médicas da Santa Casa de São Paulo, São Paulo (SP), Brazil. 2 Assistant Physician of the Service of Urology, Hospital do Servidor Público Estadual - HSPE. Urologist of the Hospital São Camilo, São Paulo (SP), Brazil. 3 Urologist, Hospital São Camilo, São Paulo (SP), Brazil. 4 Radiologist, Hospital São Camilo, São Paulo (SP), Brazil. 5 Interventional radiologist. Hospital São Camilo, São Paulo (SP), Brazil. 6 Urologist. Hospital São Camilo, São Paulo (SP), Brazil. Corresponding author: Antonio Cardoso Pinto – R. Cerro Cora, 1917B - Alto de Pinheiros - CEP 05061350 - São Paulo (SP), Brazil - Tel.: 11 3022-2044 - e-mail: antonio.cardoso@sbu.org.br Received on December 8, 2005 - Accepted on February 20, 2006 CASE REPORT