A case of primary hepatic carcinoid tumor that growth was observed for 17 years

A 65-year-old male admitted to our hospital in July 2007 due to watery diarrhea, elevation of serum liver enzymes, and liver mass. In 1990 when he was 48 years old, health check ultrasonography revealed cystic liver mass with a diameter of 2 cm. He did not receive further examination although his liver mass gradually enlarged. He had experienced recurrent duodenal ulcer and diarrhea since his adulthood. Dynamic CT scan on admission revealed an 11 cm-diameter solid tumor with cystic components in the segment 4 of the liver. Endoscopic examination for upper and lower GI, and intestine, and FDG-PET could not localize primary tumor. Left lobectomy was performed. Pathological examination revealed that the tumor was composed of cuboidal cells with round-shaped nuclei arranged in a trabecular pattern. Tumor cells were positive for Grimelius, NCAM, chromogranin A, gastrin, and serotonin. Serum gastrin and serotonin, and urine 5-HIAA were elevated. We made a diagnosis of primary hepatic carcinoid tumor manifesting both carcinoid syndrome and Zollinger-Ellison syndrome. After surgery diarrhea and duodenal ulcer disappeared along with the normalization of serum gastrin and serotonin. The calculation, based upon the observation that tumor diameter increased from 2 cm to 11 cm through 17 years, resulted in doubling time of 27.6 months. This is a very rare case of primary hepatic carcinoid tumor that growth was observed for 17 years. We also discussed the mechanisms of the cystic formation in this disease.