Primary small-cell neuroendocrine carcinoma of the gallbladder with bone metastasis: A rare presentation

Primary small-cell neuroendocrine carcinomas (NEC) of the gallbladder (GB) are rare with aggressive behavior. It has high malignancy potential with a low survival rate. In this case report, we present a case of primary small-cell NEC of GB in a 43-year-old female who presented with complaints of constipation, upper abdominal pain, and poor oral intake which was identified as a GB mass with liver nodularity on ultrasonography. It was subsequently diagnosed as a case of primary small-cell NEC of GB with liver and bone metastasis on contrast-enhanced computed tomography and core needle biopsy obtained from the left iliac bone. In view of severe jaundice, endoscopic retrograde cholangiopancreatography dilatation and stenting was done followed by palliative chemotherapy and radiotherapy. This case is unique in presenting with liver and bone metastases both instead of only liver metastasis as is commonly seen. Moreover, a sample for histopathological diagnosis was also obtained from a bony site rather than the liver as is the norm.