HEPATIC ANGIOMYOLIPOMAS: CLINICAL AND IMAGING FINDINGS
Sergio Silveira, Francisco Tustumi*, George F. Darce, Vagner B. Jeismann, Gilton M. Fonseca, Jaime Arthur Pirola Kruger, Fábio Ferrari Makdissi, Iraí Santana de Oliveira, Manoel de Souza Rocha, Fabrício F. Coelho, Paulo Herman
Universidade de Sao Paulo, Sao Paulo, São Paulo, Brazil
INTRODUCTION: Angiomyolipomas are rare mesenchymal neoplasms composed of fat, smooth muscle, and blood vessels. Most angiomyolipomas are seen in the kidney. In 20% of the patients, there is an association with tuberous sclerosis. The epithelioid subtype has an aggressive behavior, with local invasiveness, tumoral thrombosis, and metastasis. Liver angiomyolipoma (LAML) is a rare liver neoplasm, and its management is controversial. Most of the available publications are small case series. Consequently, there is no consensus on LAML treatment. The present study aims to depict the preoperative clinical and imaging findings and their association with the histological subtypes of LAML.
METHODS: All patients who underwent liver resection between 2008 to 2021 with pathologically confirmed angiomyolipoma diagnosis were included. Demographics, surgical, histological, and imaging data were extracted.
RESULTS: Among 1500 liver resections, nine patients had histologically confirmed LAMLs. Of the total, eight patients were female. The mean age of patients was 52.7 years (range: 19-76). Two patients had a preoperative diagnosis of tuberous sclerosis. The most distinctive feature of renal angiomyolipomas, gross-fat content, was only seen in 4 patients, either focal or diffuse within the nodule. Arterial phase hyperenhancement was seen in 5 out of 8 cases, and 3 cases exhibited a definitive delayed-phase washout (Figure 1). Also, a prominent hepatic artery branch was noticed in 6 cases. Since these findings are usually seen in liver adenomas and hepatocellular carcinomas, those were the main differential diagnosis. Two patients were referred to surgery after a percutaneous biopsy suggestive of LAML. One patient had hepatitis B related-chronic liver disease with a lesion liver suspicious of hepatocellular carcinoma. The remaining patients underwent surgery with undetermined lesions. The mean size of the lesions was 9.4 cm (range: 3.8-29.5). Three patients underwent major hepatectomy and four non-anatomical minor resections. Six patients were diagnosed with epithelioid LAML, two were lipomatous, and one was angiomatous. Both patients with tuberous sclerosis had epithelioid subtypes. The mean follow-up was 73.2 months (range: 1-169). During the long-term follow-up, one patient had a hepatic recurrence, and one patient had a late renal recurrence, both with epithelioid LAML.
CONCLUSION: Our series demonstrated that LAML has female predominance and is more frequently epithelioid. LALMs present with various imaging features, making the preoperative diagnosis challenging.
Figure 1. A nodule between segments 4 and 8 is seen, with small areas of micro and macroscopic fat depicted on T1 out-of-phase (A), T1 in-phase (B), and pre-contrast images (C). After contrast injection, the lesion exhibits arterial phase enhancement (D) and late-phase washout (F). This patient had a chronic hepatitis B infection, and the preoperative diagnosis was hepatocellular carcinoma.
Back to 2023 Posters