Composite adeno-endocrine carcinoma of the gallbladder with long-term survival

INTRODUCTION Primary endocrine cell tumors in the gallbladder are uncommon, and the coexistence of an endocrine cell tumor and adenocarcinoma, squamous cell carcinoma, and sarcomatoid components is extremely rare. PRESENTATION OF CASE A rare case of adeno-endocrine cell carcinoma of the gallbladder in an 81-year-old woman is reported. Abdominal ultrasonography (US) revealed a hypo-echoic, solid tumor, 2.0 cm × 1.8 cm in size, at the fundus of the gallbladder. On computed tomography (CT), the tumor was well-enhanced, well-demarcated, and homogeneous. The tumor, which was papillary, protruded into the gallbladder with no direct invasion to the liver. The tumor was diagnosed as gallbladder carcinoma; its depth appeared not to pass the subserosa layer. A cholecystectomy and hepatic bed resection with regional lymph node dissection were performed. Histologically, the tumor consisted of several components, including well to poorly differentiated papillary and tubular adenocarcinoma with squamous and sarcomatoid differentiations, and endocrine cell carcinoma. Histochemical studies of these tumor cells were positive for chromogranin A, synaptophysin, and cluster of differentiation 56 (CD56). The lymph node consisted of metastatic adeno-endocrine carcinoma. The patient survived and has remained disease-free for 4 years without adjuvant chemotherapy. DISCUSSION Adeno-endocrine cell carcinoma of the gallbladder generally has a poor prognosis. CONCLUSION The present case suggests that adeno-endocrine cell carcinoma with various components may be derived from a common precursor cell. This observation would require further investigation.