Abstract
INTRODUCTION AND IMPORTANCE: Adrenal rest tumors (ARTs) are frequently found in the abdominal axis and testis and are often detected incidentally during surgery or autopsy. The standard treatment is complete resection due to their malignant potential; however, precise preoperative diagnosis is difficult due to the similarity of the radiological findings of this disease with those of hepatocellular carcinoma (HCC) and angiomyolipoma. CASE PRESENTATION: A 58-year-old woman was diagnosed with a tumor through a physical examination and came to our clinic for a close examination. Dynamic computed tomography showed a tumor with a diameter of 27 mm that occupied segment 7 (S7) of the liver. The tumor was slightly enhanced in the arterial phase and washed out in the portal phase. Magnetic resonance imaging (MRI) demonstrated that this round tumor protruded from the liver surface and had high signal intensity on T2-weighted imaging. The tumor showed a high signal intensity on diffusion-weighted imaging. Chemical shift imaging revealed the markedly low intensity of the tumor. The preoperative diagnosis was suspected hepatic ART. Laparoscopic S7 partial resection was performed. The operative duration was 147 min, and the blood loss was 10 mL. The patient was discharged from the hospital on postoperative day 5. The pathological diagnosis was ART. CLINICAL DISCUSSION: Hepatic ART (HART) is diagnosed preoperatively as HCC in most cases, and resection is rarely reported. The most standard treatment for HART is surgery for possible malignancy. Recent advances in radiological imaging have made it possible to distinguish HART from HCC using MRI chemical shift images. In the case of a highly vascular and fatty tumor such as the present case, HART diagnosis can be made preoperatively using MRI chemical shift imaging. This case is the first reported preoperative diagnosis of HART using chemical shift imaging. CONCLUSIONS: We report a case of laparoscopic radical resection in a patient preoperatively diagnosed with hepatic ART. Chemical shift imaging in MRI is essential for distinguishing ART from HCC.