Gastric Neuroendocrine Carcinoma Presenting as Liver Abscess: A Rare Case Report

Abstract

Gastric neuroendocrine carcinomas (NECs) are rare, accounting for less than 1% of stomach malignancies. Among these, poorly differentiated small cell subtypes comprise an even smaller proportion. These tumors often present with nonspecific gastrointestinal symptoms, making diagnosis and management challenging. We report the case of a 76-year-old female presenting with progressive epigastric pain. Clinical workup included a triphasic CT scan, endoscopy with biopsy, and immunohistochemical staining. A multidisciplinary team (MDT) approach was used to guide treatment planning. Imaging revealed a malignant-appearing gastric ulcer with liver perforation and associated multiloculated abscess. Biopsy confirmed a high-grade small cell NEC with a Ki-67 index of 90%. Following nutritional optimization via nasojejunal (NJ) feeding, the patient underwent a subtotal gastrectomy, left lateral segmentectomy of the liver, and reconstruction with gastrojejunostomy and jejunojejunostomy. Histopathology confirmed Grade III poorly differentiated NEC with lymphovascular and perineural invasion and 7 of 29 lymph nodes positive. Postoperative Gallium DOTATATE PET-CT showed no metabolically active disease. This case highlights a rare presentation of gastric NEC clinically presenting as a liver abscess. Early diagnosis and a coordinated MDT strategy were pivotal in guiding surgical and oncological management. Clinicians should maintain high suspicion for aggressive gastric malignancies in atypical abscess presentations. Further research is needed to establish standardized protocols for the diagnosis and treatment of gastric NECs.