Background
Cholangiocarcinoma (CCA) is a rare and aggressive cancer of the biliary system, accounting for 15% of primary liver cancers. Most CCAs arise spontaneously, with risk factors including primary biliary cirrhosis, liver fluke infection, and biliary malformations. A newly described variant, Inhibin-positive Cholangioblastic (solid-tubulocystic) intrahepatic cholangiocarcinoma (iCCA), mimics neuroendocrine tumors (NET). This report presents a case of this new variant.
Case Presentation
A 53-year-old female with a history of alcohol use disorder and no family history of liver cancer presented with watery diarrhea for a month. Blood tests, including tumor markers, were normal. An ultrasound revealed a large mass in the right hepatic lobe. CT and MRI scans suggested a hemangioma. Due to the mass’s size and spontaneous bleeding risk, she underwent surgical resection. The mass was initially thought to be a hemangioma but was later identified as poorly differentiated intrahepatic CCA with a solid and tubulocystic structure. Pathology showed strong staining for Cytokeratin (CK) 7, CK-19, and Inhibin, and weak staining for synaptophysin, confirming a diagnosis of cholangioblastic iCCA. Genetic testing revealed no actionable variations. She was started on capecitabine for 8 cycles. Follow-up imaging showed no disease recurrence or metastasis.
Discussion
CCA often presents at advanced stages with symptoms like weight loss and jaundice. Diagnosis involves clinical assessment, lab work, and imaging, particularly MRI. Cholangioblastic Intrahepatic CCA (iCCA) is a newly described variant of cholangiocarcinoma. There have been 16 reported cases of the disease. Initially, it was thought to be a NET as it expressed Chromogranin, insulinoma-associated protein-1, and Synaptophysin. Almost half of the reported cases were diagnosed as NET initially. One tool clinicians can use to differentiate them is inhibin. Inhibin has been documented in all of the reported cases of Cholangioblastic iCCA. A novel inhibin-positive cholangioblastic iCCA variant with a Nipped-B-like protein and nucleus accumbens associated-1 (NIPBL-NACC1) fusion transcript has been reported recently, further helping differentiate the two. There is no standard of therapy for this variant. It’s managed similarly to CCAs, relying on surgical resection as the primary treatment. Limited data shows varied responses to neoadjuvant and adjuvant therapy.