Two cases of neuroendocrine carcinoma of the gallbladder

Abstract

Neuroendocrine carcinoma (NEC) of the gallbladder is a rare subtype of gallbladder tumor. Here, we report two cases of NEC in two patients initially suspected to have gallbladder carcinoma. No specific symptoms or abnormal blood test results were observed preoperatively. Abdominal computed tomography scans indicated intraluminal masses in the gallbladder and lymph node enlargement in the hepatic hilum. Radical cholecystectomy and regional lymphadenectomy were performed. The first patient also presented with liver invasion and therefore underwent resection of liver segment IV. A diagnosis of NEC was made upon postoperative pathological examination and immunohistochemical staining according to the WHO Classification of Tumors of the Digestive System (2010). One tumor was identified as poorly differentiated NEC and the other as poorly differentiated mixed adenoneuroendocrine carcinoma. Immunohistochemical staining data from both tumors showed positivity for chromogranin A and synaptophysin. The first patient received 4 cycles of chemotherapy consisting of cisplatin and etoposide. No metastases or recurrence were observed 12 mo following surgery. The second patient refused chemotherapy and presented with tumor recurrence 4 mo after surgery. In conclusion, NEC of the gallbladder is an aggressive tumor and the identification of a standardized optimal treatment still requires further research. Our experience together with published studies suggests that radical surgery and adjuvant chemotherapy may improve the prognosis.

Primary neuroendocrine tumors of the gallbladder: Ultrasonographic and MDCT features with pathologic correlation

“…The definite diagnosis is based on immunohistochemical expression of marker proteins. In our two patients, immunohistochemical analysis showed that tumor cells were negative for cytokeratin and vimentin and positive for CD 56, chromogranin A and synaptophysin, thus supporting the final diagnosis of neuroendocrine tumor [2,3,9].…”

“…In some reports, the tumor itself was not visible at imaging and was found incidentally during histopathological analysis of resected specimen after surgical resection of the gallbladder for another reason that the tumor itself [4][5][6]. In other cases, the tumor presented as an irregular, circumferential thickening of the gallbladder [2] or as an intraluminal polypoid mass [2,3,7] similar to the findings observed in the more common adenocarcinoma of the gallbladder [6,8]. Primary neuroendocrine tumors of the gallbladder may also present as chronic cholecystitis with circumferential, homogeneous thickening of the gallbladder wall with intraluminal stones [9].…”

“…MDCT findings were suggestive for the diagnosis of gallbladder adenocarcinoma. The final diagnosis was made after histopathologic analysis similar to prior cases reported in the literature [2,3,9,10]. Of interest, in both patients, the metastatic lymph nodes were abnormally enlarged, which is a finding that has not been reported neither in previous cases of primary neuroendocrine tumors of the gallbladder nor in the most common gallbladder adenocarcinoma.…”

“…Histopathologically, primary neuroendocrine tumors of the gallbladder are predominantly poorly differentiated neuroendocrine tumors [2,3,9]. The definite diagnosis is based on immunohistochemical expression of marker proteins.…”

“…Conversely, primary neuroendocrine tumors of the gallbladder are extremely rare, representing 0.2 % of all neuroendocrine tumors and only 2 % of all gallbladder carcinomas [2]. The diagnosis of primary neuroendocrine tumors of the gallbladder is usually made during histopathological analysis because no suggestive imaging features that allow discriminating between this specific tumor and the more common gallbladder adenocarcinoma have been described [3].…”