Very rare metastatic phenomena of biliary tract cancer to the cerebellum: A case report and review of the literature

INTRODUCTION AND IMPORTANCE: The occurrence of brain metastasis due to cholangiocarcinoma is an exceedingly uncommon phenomenon, documented in only a few numbers of published cases. Recent studies indicated an incidence rate of just 0.15 % for brain metastases in connection with this condition, which was also linked to a reduced survival rate. CASE PRESENTATION: A 58-year-old woman with a history of hepatobiliary cholangiocarcinoma presented with a recent onset of unsteady walking, dizziness, vomiting, and worsening occipital headaches. Her medical history included successful chemotherapy treatment for her cholangiocarcinoma. Neurological examination revealed right-sided cerebellar deficits, and imaging indicated a sizable lesion in the right cerebellar hemisphere with surrounding vasogenic edema. A PET scan revealed a liver lesion but no other significant abnormalities. The recommended approach was surgical excision of the cerebellar lesion to relieve symptoms, halt deterioration, and obtain a tissue sample for analysis. After comprehensive discussions with the patient and her family, they opted for the surgical procedure. CLINICAL DISCUSSION: The major contributors to brain metastases include lung cancers, breast cancers, testicular cancers, melanomas, and renal tumors. In contrast, brain metastases originating from gastrointestinal cancers are less frequent, accounting for fewer than 4 % of cases, with notable impact on 1 % of colorectal cancers, 0.62 % of gastric cancers, and 0.33 % of pancreatic cancers. However, brain metastases are extremely rare. CONCLUSION: This study underscores the significance of anticipating and identifying brain metastases in biliary tract cancers, even in the face of their low incidence and the limited amount of available literature on the subject.