Neuroendocrine tumors (carcinoid and neuroendocrine carcinoma) presenting at extra-appendiceal sites in childhood and adolescence.

OBJECTIVE: Epithelial neuroendocrine neoplasms arising outside the appendix are extremely rare in the pediatric population. We reviewed the clinicopathologic characteristics of 13 carcinoid tumors and neuroendocrine carcinomas presenting at extra-appendiceal sites to better characterize this rare set of neoplasms in childhood.
DESIGN: The pathology archives of M. D. Anderson Cancer Center and Texas Children's Hospital were searched for cases of carcinoid tumor and neuroendocrine carcinoma arising at extra-appendiceal sites in children. Hematoxylin-eosin-stained sections and, when available, immunohistochemistry, electron photomicrographs and gross photographs were reviewed. The tumors were classified as either carcinoid tumor or neuroendocrine carcinoma based upon histopathologic features. Demographic information was obtained from review of the surgical pathology reports, autopsy reports, and clinical charts. PATIENTS: The study population included 8 males and 5 females, ranging in age from 8 to 18 years.
RESULTS: The majority of the cases were classified as carcinoid tumors (8/13), with the remainder being neuroendocrine carcinomas (5/13). The lung was the initial site of presentation in most children (6/13). The liver was the next most common site (5/13) of tumor presentation with no other primary site identified. Neuroendocrine carcinoma within an inguinal lymph node, with no primary tumor site identified, was present in a single case. The final case was a neuroendocrine carcinoma with widespread involvement of multiple organs with no definitive primary site identified.
CONCLUSION: Carcinoid tumors and neuroendocrine carcinomas presenting at extra-appendiceal sites in children primarily involve the lungs or liver. These neuroendocrine neoplasms have the ability to metastasize, regardless of histology at initial diagnosis.