Ampullary Large-Cell Neuroendocrine Carcinoma, a Diagnostic Challenge of a Rare Aggressive Neoplasm: A Case Report and Literature Review

Abstract

Ampullary large-cell neuroendocrine carcinomas (LCNECs) are extremely rare, and available data are limited on case reports. They present with jaundice, non-specific abdominal pain, or weight loss, imitating adenocarcinoma. Their incidence increases due to the improved diagnostic techniques. However, preoperative diagnosis remains challenging. We report the case of a 70-year-old man with a history of metabolic syndrome, cholecystectomy, and right hemicolectomy, presenting with jaundice. Laboratory results showed increased liver biochemistry indicators and elevated CA 19-9. Esophagogastroduodenoscopy revealed an ulcerative tumor on the ampulla of Vater, and the biopsy revealed neuroendocrine carcinoma. Although computed tomography (CT) detected enlarged regional lymph nodes, the positron emission tomography (PET) showed a hyperactive lesion only in this area. Pylorus-preserving pancreatoduodenectomy with R0 resection was performed. Pathologic evaluation of the 3.1 × 1.9 cm tumor revealed an LCNEC with immunohistochemical positivity at Synaptophysin, EMA, CD56, and cytokeratin CK8/18. The Ki-67 index was 45%. Two out of the nine dissected lymph nodes were occupied by the neoplasm. The patient was discharged home free of symptoms, and adjuvant chemotherapy with carboplatin + etoposide was initiated. A comprehensive review of the reported cases showed that the preoperative biopsy result was different from the final diagnosis in few cases, regarding the subtypes. Conventional radiology cannot identify small masses, and other methods, such as endoscopy, magnetic resonance cholangiopancreatography (MRCP), and FDG-PET scan, might aid the diagnosis. Diagnosis is based on histology and immunohistochemical markers of the surgical specimens. The treatment of choice is pancreatoduodenectomy, followed by adjuvant chemotherapy. However, recurrence is frequent, and the prognosis remains poor.

Obstructive Jaundice Caused by Metastatic Neuroendocrine Tumor of the Ampulla of Vater in a Young Adult: A Case Report

“…Studies have shown a steadily rising age-adjusted incidence rate in small intestinal NETs. The highest incidence was in the population between 70 and 79 years, and the lowest was between 20 and 29 years; however, no cases were reported <20 years of age [ 4 , 9 , 10 ]. The patient in this case presented at the age of 18 years with symptoms of abdominal pain and jaundice suggestive of biliary obstruction.…”

“…An autopsy registry analysis from Sweden reported a mean annual incidence of 5.33 per 100,000 individuals [ 1 ]. Ampullary NETs are extremely rare and represent less than 0.3% of all gastroenteropancreatic neuroendocrine neoplasms [ 4 ].…”

“…Here, we present a case of small intestinal NET occurring at a very young age. To the best of the authors’ knowledge, this is the first case of NET of the ampulla of Vater with lymph node metastases reported in a patient <20 years of age [ 4 , 9 ]. This case highlights the importance of a multidisciplinary approach in the diagnosis and management of NETs and demonstrates the efficacy of radical surgical treatment on these tumors.…”

Diagnostic Management of Gastroenteropancreatic Neuroendocrine Neoplasms: Technique Optimization and Tips and Tricks for Radiologists

“…In the prognosis and management of GEP-NENs, the Ki-67 labelling index and mitotic count are critical indicators of the state of tumor proliferation [ 14 , 15 ]. The WHO classifications of NENs have been updated from previous classifications differentiating neuroendocrine tumors (NETs) and poorly differentiated neuroendocrine carcinoma (NECs), according to the Ki-67 index and mitotic count [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ] ( Table 2 ).…”