Primary hepatic neuroendocrine carcinoma in a child. Morphologic, immunocytochemical, and molecular biologic studies.

BACKGROUND: Primary neuroendocrine tumor of the liver is uncommon, and virtually all reported patients with the tumor have been adults. Most of the tumors were carcinoids. The authors report an 8-year-old girl with primary hepatic neuroendocrine carcinoma.
METHODS: Histologic, ultrastructural, and immunocytochemical studies and Southern blot analysis of tumor N-myc DNA were performed in the patient.
RESULTS: Histologically, the tumor revealed a characteristic organoid pattern with a spectrum of differentiation varying from well-differentiated carcinoid-like areas to poorly differentiated pleomorphic areas. Ultrastructural features included neurosecretory granules and interdigitating cytoplasmic extensions. The tumor cells showed immunoreactivity to neuron-specific enolase (NSE), S-100 protein, chromogranin, and synaptophysin. No evidence of amplification of tumor N-myc DNA was present. However, the molecular weight of the tumor N-myc DNA (1.8 kb) was significantly lower than the normal control (from normal liver tissue) (2.0 kb).
CONCLUSIONS: This report documents the occurrence of primary hepatic neuroendocrine carcinoma in a child. Thorough studies and complete clinical evaluation are essential to the establishment of diagnosis. The result of N-myc DNA analysis probably is attributable to deletion of part of the tumor N-myc gene. The clinical implication of this finding is unknown, and additional investigation is warranted.