Concomitant Small Cell Neuroendocrine Carcinoma ofGallbladder and Breast Cancer

The neuroendocrine carcinoma is defined as a high-grade malignant neuroendocrine neoplasm arising from enterochromaffincells, usually disposed in the mucosa of gastric and respiratory tracts. The localization in the gallbladder is rare. Knowledge ofthese gallbladder tumors is limited and based on isolated case reports. We describe a case of an incidental finding of small cellneuroendocrine carcinoma of the gallbladder, observed after cholecystectomy for cholelithiasis, in a 55-year-old female, whoalready underwent quadrantectomy and sentinel lymph-node biopsy for breast cancer. The patient underwent radiotherapy forbreast cancer and six cycles of chemotherapy with cisplatin and etoposide. Eighteen months after surgery, the patient was free fromdisease. Small cell neuroendocrine carcinoma of the gallbladder has poor prognosis. Because of the rarity of the reported cases,specific prognostic factors have not been identified. The coexistence of small cell neuroendocrine carcinoma of the gallbladderwith another malignancy has been reported only once.The contemporary presence of the two neoplasms could reflect that bioactiveagents secreted by carcinoid can promote phenotypic changes in susceptible cells and induce neoplastic transformation.