The management of extrapulmonary poorly differentiated (high-grade) neuroendocrine carcinomas.

Extrapulmonary high-grade neuroendocrine carcinomas (HGNECs) are rare but aggressive tumors that can be found throughout the body but are most commonly located in the gastrointestinal (GI) and the genitourinary tracts. They also have been described in the thymus, breast, oropharynx, and other organs. Due to the rarity of these tumors, publications are limited to small series and, as a result, treatment regimens are extrapolated from more robust data published on pulmonary HGNECs. For metastatic disease, platinum-based chemotherapy is the backbone of treatment. For localized disease, there are currently no standard treatment algorithms. Surgical resection with low morbidity is a reasonable treatment option, particularly in lesions where the possibility of obstruction is high. However, given the very high risk of disease recurrence, a multimodality approach with either neoadjuvant or adjuvant therapy is warranted. For locally advanced disease, chemoradiation should be considered, incorporating a platinum-based regimen when possible. Chemoradiation also should be considered when primary resection would lead to significant morbidity, such as with rectal, pancreas, and esophageal HGNECs.