Flushing as atypical initial presentation of functional gallbladder neuroendocrine carcinoma: A case report

BACKGROUND: Neuroendocrine neoplasms are rarely located in the gallbladder (GB), and carcinoid syndrome is exceedingly rare in patients with GB neuroendocrine neoplasms. CASE SUMMARY: We report a case of GB neuroendocrine carcinoma (GB-NEC) in a 65-year-old man, who presented with flushing for 2 mo. Pathological specimens of the flushed skin revealed that mucin was deposited between the collagen bundles in the dermis. Computed tomography and magnetic resonance imaging indicated neoplasm in the GB with liver invasion and enlarged lymph nodes in the portacaval space. High fluorodeoxyglucose uptake was detected in lymph nodes in the portacaval space, but distant metastasis was not seen by positron emission tomography. Ultrasound-guided needle biopsy of the GB neoplasm was suggestive of high-grade NEC. Because of the functional characteristics of poorly differentiated NEC, en bloc cholecystectomy, resection of hepatic segments IVb and V, pancreaticoduodenectomy, and regional lymphadenectomy were performed. A diagnosis of poorly differentiated NEC was made by pathological findings and immunohistochemical staining data. Ki-67 index was > 80%. The patient refused adjuvant therapy and passed away in the 7(th) month. CONCLUSION: Distinctive manifestation combined with imaging helps make correct preoperative diagnosis. Radical surgery and adjuvant chemotherapy might improve prognosis.