Hepatocellular Carcinoma with Gastric Metastasis Mimicking a 4 cm Gastrointestinal Stromal Tumor After a 3-year Disease-free Interval.

Hepatocellular carcinoma (HCC) is an aggressive tumor that usually occurs in patients with chronic liver disease and cirrhosis. Surgical resection is an optimal treatment for HCC, but the 5-year recurrence rates are significantly high. The majority of recurrent HCCs occur through intrahepatic metastasis with local tumor progression, and less than 20% of recurrences are extrahepatic metastases. HCC with gastric metastasis is extremely rare, and it is easily misdiagnosed as primary gastric cancer with liver metastasis. An 80-year-old male chronic hepatitis B virus carrier had received lamivudine and entecavir for years and was regularly followed up in the clinic. He had a 3.5 cm solitary HCC with microvascular invasion and received curative surgical resection in 2009. In 2013, he developed a 1.3 cm solitary HCC again and was treated with combination therapy with radiofrequency ablation and pure ethanol injection. Afterwards, he was followed every 3-6 months and was HCC-free. Three years later, in 2016, endoscopy for intermittent epigastralgia showed a solitary 4 cm intraluminal gastric subepithelial tumor without mucosal ulcers or erosions over the gastric fundus. All imaging studies, including computed tomography, favored the diagnosis of gastrointestinal stromal tumor (GIST), but the pathology of the tumor proved to be HCC. The patient did not receive any systemic anticancer therapy but only wedge resection of the stomach and remained tumor- and HCC-free until his latest clinic visit in 2023. The current case is unique and indicates the possibility of HCC with late solitary gastric metastasis mimicking GIST. Complete gastric tumor resection ensured an extremely good outcome for the patient, which is different from the devastating prognosis of most cases of HCC with gastric metastasis.