Cholangiolocellular Carcinoma Misdiagnosed As Hemangioma: Unique Central Fibrotic Area Devoid of Cancer Cells Detected on a Seven-Year Follow-Up.

Cholangiolocellular carcinoma, a subtype of peripheral-type intrahepatic cholangiocarcinoma, is a relatively rare primary liver tumor. This case report describes a patient with cholangiolocellular carcinoma that was initially misdiagnosed as hemangioma, and ultimately underwent complete tumor resection after a seven-year follow-up period. A 72-year-old female patient with a history of chronic hepatitis C was followed up regularly at the hospital. Computed tomography (CT) performed seven years prior had detected a small tumor (12 mm) with radiographic characteristics suggestive of hemangioma. The tumor increased in size from 12 to 32 mm over the next seven years. On CT, the tumor showed poor central enhancement, indicating reduced blood flow in the central region. Due to the suspicion of malignancy, partial surgical resection was performed. Pathological examination confirmed a diagnosis of cholangiolocellular carcinoma. The carcinoma exhibited vascular invasion and a broad central fibrous area with hyalinization, lacking epithelial cells, and marked by venous obstruction. This case underscores the challenge of distinguishing cholangiolocellular carcinoma from hemangioma, particularly in small tumors with similar radiological features. The findings highlight the importance of employing additional diagnostic modalities such as ultrasound and magnetic resonance imaging, as well as the necessity of biopsy when suspicion arises. This case also describes the unique finding of a central fibrous area without tumor cells, which may have resulted from localized circulatory disturbances potentially caused by tumor embolism in the portal and hepatic veins. This pathological finding provides valuable insights into the nature of this rare tumor.