Dados do Trabalho

Título

Multifocal Nodular Steatosis Mimicking Liver Metastasis

Descrição sucinta do(s) objetivo(s)

This case report aims to detail the management of a patient with multifocal steatosis, emphasizing the variety of diagnostic methods used and the specific characteristics that help differentiate the various possible differential diagnoses.

História clínica

A 58-year-old female patient is undergoing routine examinations at a reference oncology hospital. Abdominal ultrasound showed multiple isoechoic masses with an echogenic rim in the liver. At contrast-enhanced computed tomography (CT), those lesions were isodense to the liver parenchyma with a hypodense rim.

Discussão e diagnóstico

Because of the suspicion of metastatic lesions, a magnetic resonance imaging (MRI) exam was also performed, which revealed multiple hepatic masses with signal intensity and enhancement similar to the liver parenchyma, measuring up to 24 mm. A well-defined rim was noted in these masses, which show a signal drop in "chemical shift" sequences (best visualized in the "out of phase" sequence), suggesting a fatty component and indicating the possibility of multifocal nodular steatosis. At 13-month follow-up, these lesions remained stable. Hepatic steatosis is a term applied to triglyceride accumulation within the hepatocytes and tends to be most important around the central veins (hypoxic area). It can occur because of nonalcoholic fatty liver disease (NAFLD), alcoholism, chemotherapy, metabolic, toxic, and infectious causes. The most common pattern is diffuse form; however, it can present in heterogenous, focal, multinodular, perilesional, perivascular, subcapsular, and lobar forms. Hypersteatosis and multinodular forms can mimic metastasis in patients with cancer, and it is an important differential diagnosis. Multifocal nodular fatty infiltration is visualized as a highly echoic lesion on sonography, as a low-density area with no mass effect on CT. MRI shows these lesions as hypointense on T1-weighted out-of-phase images, isointense on T1-weighted in-phase images, and slightly hyperintense on T2-weighted images. Hepatic nodules were visualized in the arterial phase but without significant contrast enhancement in the hepatobiliary phase. Diffusion-weighted imaging (DWI) shows no signal of restriction of liver nodules.

Conclusões

Correct diagnosis is difficult and sometimes requires a percutaneous biopsy to prove the presence of fat within the lesion.

Palavras Chave

steatosis; liver metastasis; differential diagnosis.

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