56 Recent research by a group of international pathologists has highlighted enteroblastic cholangiocarcinoma, a particularly rare type of bile duct cancer. The study, which reviewed four cases across various countries, indicates that this unique carcinoma subtype might have gone underreported, despite its potentially aggressive nature and complex diagnosis. The findings were published in the journal Human Pathology. Enteroblastic cholangiocarcinoma stands out due to its association with elevated levels of alpha-fetoprotein (AFP), a marker typically linked to fetal development. Though AFP elevation is more common in cancers of the stomach and liver, the presence of this protein in bile duct cancer cases prompted researchers to take a closer look at enteroblastic cholangiocarcinoma. The study describes a distinctive pattern of cuboidal or polygonal cancer cells, which often bear a clear cytoplasm and subnuclear vacuoles, arranged in structures resembling foetal gut tissue. In three cases, patients had an initial diagnosis followed by surgical resection, while one case had to be managed solely with a needle biopsy, showing the challenges of diagnosing such an uncommon subtype. The cancer was found in two main locations: within the liver and in the common bile duct. For patients with intrahepatic bile duct cancers, an elevated AFP level was detected, confirming the aggressive cancer signature. Two of the cases had underlying primary sclerosing cholangitis, a liver condition known to heighten the risk for bile duct cancers, raising further questions about the link between liver inflammation and the onset of enteroblastic cholangiocarcinoma. Pathologists have noted that, based on their findings, the cancer subtype might be prone to occurring in regions outside the liver, including the gallbladder and the broader biliary tree. While liver or biliary tract cancers associated with hepatoid characteristics are rare, even fewer studies have examined enteroblastic carcinoma. This scarcity in research has led to challenges in identifying and accurately diagnosing cases. For example, the study team noted that tumours with a combination of clear cell characteristics and subnuclear vacuoles might have previously been grouped under the more general label of “clear cell cholangiocarcinoma.” However, the recent research suggests that these characteristics, combined with elevated AFP, should trigger a more specific diagnosis. Immunohistochemistry tests revealing markers such as AFP, SALL4, and glypican 3 are critical for distinguishing enteroblastic cholangiocarcinoma from other, more common forms of bile duct cancer. Treatment outcomes among the four cases were mixed, highlighting the aggressive nature of this cancer. One patient survived eight months with stable disease progression under chemotherapy, while another succumbed to the disease 17 months post-surgery. The other two patients who underwent surgical resection showed no recurrence of cancer during their follow-up periods, which varied between 14 and 18 months. However, with such a small sample, the study emphasises the need for more extensive research to better understand prognosis and survival rates for this rare condition. The findings highlight the challenges faced by medical professionals in identifying enteroblastic cholangiocarcinoma and underscore the importance of recognising specific cellular markers. With more awareness, pathologists may be able to identify additional cases, ultimately contributing to a fuller understanding of this uncommon yet aggressive bile duct cancer subtype.