Hepatic epithelioid angiomyolipoma mimicking hepatocellular carcinoma

Hepatic epithelioid angiomyolipoma: magnetic resonance imaging characteristics

PURPOSE

The aim of the study was to analyze MR imaging features of hepatic epithelioid angiomyolipoma (HEAML).

METHODS

This study included 113 patients with 122 pathologically confirmed HEAML who underwent enhanced MRI scanning before partial hepatectomy. MR images were retrospectively reviewed and correlated with pathological findings.

RESULTS

The mean age of 113 patients was 48.12 ± 11.77 years old, and the male to female ratio was 1:3.35 with 87 females (76.99%). 107 (94.69%) patients presented as single tumor, and 96 patients (84.96%) were asymptomatic. 122 HEAML lesions were diagnosed pathologically in 113 patients, with the average of 4.47 ± 3.26 cm. 109 lesions (89.34%) and 108 lesions (88.52%) showed regular and well-defined boundary. On T1WI, 121 lesions (99.18%) mainly presented hypointensity. On T2WI, 118 lesions (96.72%) and 109 lesions (89.34%) mainly showed hyperintensity and heterogeneous signals. Most of the lesions (97.46%) showed hyperintensity on DWI. 118 lesions (96.72%) manifested as severe hyperenhancement and 106 lesions (86.89%) showed heterogeneity during the arterial phase. As for the lesion enhancement pattern, 73 lesions (59.84%) presented as persistent enhancement, 37 lesions (30.33%) as wash out, 8 lesions (6.56%) as degressive enhancement, and 4 lesions (3.28%) as poor blood supply. Additionally, 96 lesions (78.69%) with intra-tumor vessels and 85 lesions (69.67%) with outer rim were confirmed during the delayed phase.

CONCLUSION

At enhanced MRI, hypointensity on T1WI, hyperintensity and heterogeneous signals on T2WI, hyperintensity on DWI, little or no fat component, heterogenous hyperenhancement, persistent enhancement, intra-tumor vessels, and outer rim would be helpful to diagnose HEAML.

Ultrasound contrast agent Sonazoid for the diagnosis of hepatic epithelioid angiomyolipoma: a case report

Background

An angiomyolipoma usually occurs in the kidneys and rarely in the liver. Hepatic epithelioid angiomyolipoma (HEAML), a rare variant of angiomyolipoma, possesses malignant potential and mimics the imaging features of hepatocellular carcinoma. Sonazoid® (perfluorobutane microbubbles), a new contrast agent that facilitates hepatic parenchyma-specific Kupffer phase imaging on contrast-enhanced ultrasonography (CEUS), is useful for the detection and characterization of focal liver lesions.

Case presentation

A 30-year-old man with HEAML underwent CEUS using Sonazoid®, in which new concepts for ultrasonography-based differentiation between HEAML and hepatocellular carcinoma were applied.

Conclusions

This case report provides clinicians and radiologists with a reference for distinguishing HEAML from hepatocellular carcinoma based on CEUS using Sonazoid®.

Baseline and contrast-enhanced ultrasound features of hepatic epithelioid angiomyolipoma

BACKGROUND

Recurrence or metastasis after surgery had been reported in hepatic epithelioid angiomylipoma (epi-AML). Most hepatic epi-AMLs were misdiagnosed with hepatocellular carcinoma or other hepatic tumors before surgery.

OBJECTIVE

To describe the baseline and contrast-enhanced ultrasound (CEUS) features of hepatic epi-AMLs and to explore the potential ultrasonic features for prognosis.

METHODS

The retrospective study enrolled 67 patients (56 females, 11 males) with 67 pathologically confirmed hepatic epi-AML lesions. All the lesions were examined by baseline ultrasound and 42 lesions were examined using CEUS with SonoVue (Bracco, Milan, Italy) before surgery.

RESULTS

Baseline ultrasound features of hepatic epi-AMLs included heterogeneous echo (86.6%), well-defined border (68.7%), hypoecho (64.2%), regular morphology (62.7%), peripheral-tumor arc-shaped or ring-like vessels (53.7%), and low value of resistive index (0.51±0.08). CEUS features of hepatic epi-AMLs included arterial phase hyper-enhancement with smooth and well-defined margin (100%), peripheral-tumor ring-like vessels (57.1%), and intra-tumor vessels (52.4%). Some CEUS features, including arterial phase heterogeneously tortuous filling, intra-tumor vessels and peripheral-tumor ring-like vessels were more commonly found in hepatic epi-AMLs of uncertain malignant potential/malignant than in benign hepatic epi-AMLs (p <  0.05).

CONCLUSIONS

Baseline ultrasound and CEUS features may be useful in diagnosis of hepatic epi-AML, and some CEUS features may be indicative of its malignant potential.

Epithelioid angiomyolipoma of the pancreas: A case report and review of the literature

BACKGROUND

Angiomyolipomas (AMLs), belonging to the family of mesenchymal tumors, are considered benign lesions that occur mostly in the kidney or as a part of tuberous sclerosis. Epithelioid AML (EAML) is a rare type of AML that appears to have malignant potential. Extrarenal AMLs usually occur in the liver according to the retrieved literature reports. There have been only two previous reports of monofocal primary AML of the pancreas; however, no cases of primary monotypic EAML of the pancreas have been reported.

CASE SUMMARY

An asymptomatic 59-year-old woman incidentally revealed a tumor during abdominal ultrasound examination. Routine blood tests and physical examination were within normal limits. Abdominal ultrasound revealed a 1.9-cm hypoechogenic mass in the tail of the pancreas, clearly visualized by endoscopic ultrasound. However, contrast-enhanced abdominal computed tomography scans did not demonstrate the lesion. A subsequent gadolinium-enhanced magnetic resonance imaging scan showed that the lesion had some characteristic manifestations. The lesion was initially thought to be a neuroendocrine tumor (asymptomatic PanNET). After surgical resection, histopathology and immunohistochemistry confirmed the diagnosis of EAML. At the 6-mo follow-up, no recurrence, spread, or metastasis was identified on computed tomography or magnetic resonance imaging.

CONCLUSION

The preoperative diagnosis of pancreatic AML is extremely difficult. Imaging techniques are essential for providing valuable morphological features for differential diagnosis.