Early detection of occupational cholangiocarcinoma in a high-risk patient under intensive surveillance: a case study.

BACKGROUND: Occupational cholangiocarcinoma is associated with exposure to organic solvents, such as dichloromethane (DCM) and 1,2-dichloropropane (DCP). This report describes a case of occupational cholangiocarcinoma detected through regularly imaging following the discovery of elevated serum γ-glutamyl trans peptidase (γ-GTP) levels revealed during regular checkup.

CASE PRESENTATION: A 43-year-old man who had been working in a printing company with 15 years of exposure to organic solvents presented to our hospital owing to abnormalities found during a routine checkup. Ultrasound (US) imaging revealed thickening of the gallbladder wall accompanied by gallstones, although in the blood tests, γ-GTP levels were within normal range. Given the high risk of cholangiocarcinoma development, the patient underwent regular monitoring with abdominal US and blood tests at a local doctor's office. At the age of 48, his serum γ-GTP level mildly elevated for the first time, prompting the initiation of semi-annual magnetic resonance cholangiopancreatography (MRCP). By the age of 50 years, dilation in B8 was detected, and one and a half years later, a tumor on the central side of the B8 dilation appeared. The patient was diagnosed with intrahepatic cholangiocarcinoma, which was treated with anterior sectionectomy. Pathological examination revealed an adenocarcinoma with a papillary glandular ductal structure at the root of the B8. In addition, biliary intraepithelial neoplasia (BilIN) and dysplasia have been identified around the tumor and periphery bile ducts and in noncancerous bile ducts. Postoperatively, the patient received 6 months of adjuvant chemotherapy with S-1monotherapy. Eight months after surgery, the patient remained under observation with no signs of recurrence.

CONCLUSIONS: We report a case of occupational cholangiocarcinoma detected during a prolonged period of regular follow-up after exposure to DCM and DCP. Given the delayed carcinogenesis process, occupational cholangiocarcinomas manifest long after exposure to organic solvents, therefore, ongoing screening is extremely important. Vigilance is essential to avoid underdiagnosis, particularly for individuals who are at an increased risk of developing this form of cancer. Continuous monitoring is key to the early detection and effective management of occupational cholangiocarcinoma.