Metastatic Gastrointestinal Carcinoid Tumor with Unknown Primary Site

Carcinoid tumors are rare and slow growing malignancies derived from enterochromaffin cells. Two-thirds of carcinoid tumors arise in the gastrointestinal tract, and in 3% of these cases the primary site cannot be determined. Presenting symptoms depend on the location of the primary tumor but may be nonspecific, and in 13% of patients distant metastases are discovered on diagnosis. The classic carcinoid syndrome occurs in less than 10% of cases and only after metastasis to the liver. We present a case of a young woman with a gastrointestinal carcinoid tumor of unknown site that had metastasized to the liver. We also provide a review of the current diagnostic modalities. Familiarity with the signs and symptoms of carcinoid tumors and the diagnostic techniques thereof may facilitate early detection and improved outcome.