Rare Tumor Mystery: When Benign Mimics Malignant

Isolated neurofibromas of the gallbladder (GB) and common bile duct (CBD) are exceptionally rare benign tumors, often mimicking malignancies and posing diagnostic challenges. This paper reports the unique case of a 32-year-old male presenting with right upper quadrant pain, jaundice, and clay-colored stools. Imaging revealed a septate GB with mural thickening, a gallstone, and distal CBD annular thickening, indicating a dual malignancy (GB carcinoma and cholangiocarcinoma). A hepato-pancreatic-duodenectomy was performed because of a suspected malignancy. The histopathology examination unexpectedly revealed spindle cell lesions positive for S100 and neurofilament protein, confirming a primary neurofibroma of the GB and CBD. This first reported case of simultaneous dual-site involvement highlights the diagnostic difficulty because of malignancy mimicry, advocating for intraoperative frozen sections to guide surgical management and avoid overtreatment.