Poorly Differentiated Neuroendocrine Tumor of the Esophagus with Hypertrophic Osteoarthropathy and Brain Metastasis: A Success Story.

Neuroendocrine carcinomas (NECs) of the esophagus are very rare. The majority of the patients with NECs present with metastasis. Paraneoplastic syndromes, such as syndrome of inappropriate secretion of anti-diuretic hormone and watery diarrhea-hypokalemia-achlorhydria syndrome, have been reported in previous reports. Esophageal NECs are related to a poor prognosis. A 38-year-old male with the histologic diagnosis of esophageal NEC, which initially manifested as hypertrophic osteoarthropathy (HOA), later developed brain metastases. He was initially treated with neoadjuvant chemotherapy consisting of cisplatin and etoposide followed by a partial esophagectomy in November 2009. At follow-up in February 2010, he complained of a headache that prompted imaging. MRI of the brain revealed a left frontal lobe lesion. Subsequently, he underwent a craniotomy and resection of the lesion. Pathological analysis revealed that the lesion was consistent with metastatic disease from the primary esophageal NEC. The patient underwent 40 Gy whole brain radiotherapy (WBRT), followed by two weeks of stereotactic radiation (SRS) to the tumor bed for an additional 12 Gy. During this time, his tumor marker neuron-specific enolase (NSE) initially dropped but later increased, which led us to offer him radiotherapy to the remaining esophagus to be followed by localized radiation to areas immediately adjacent to the surgical site, followed by six cycles of systemic chemotherapy consisting of cisplatin and irinotecan. Finally, his NSE normalized around the end of systemic chemotherapy. Surveillance imaging in 2015 - six years from initial diagnosis - showed no evidence of cancer. Of interest, treatment of the esophageal NEC also led to clinical resolution of his musculoskeletal symptoms, including his HOA. High-grade esophageal NECs are rare, aggressive, and have a poor prognosis. HOA can be a presenting sign associated with a high-grade esophageal NEC. The predominant site of metastatic spread is the liver, but metastases to rare sites, such as the brain, can occur, as was the case in our patient. Better survival has been reported for patients with locoregional disease compared to patients with distant metastases. However, multidisciplinary management can lead to an improved outcome in selected patients with distant metastases.