Rare Mixed Adenoneuroendocrine Carcinoma of the Gallbladder: Case Report and Review of Literature.

BACKGROUND Mixed adenoneuroendocrine carcinoma of the gallbladder (gMANEC) is an extremely rare cancer. Most of the cases are reported in Asia, North America, and Europe, with no cases reported in Latin America; this is the first report for this region, and the 24th case reported worldwide. CASE REPORT A 68-year-old woman was referred to our department due to asthenia and moderate abdominal pain in the right upper quadrant for 6 months, with imaging examinations showing a solid heterogeneous expansive lesion in gallbladder topography and segment IV of the liver. The MRI displayed an expansive and heterogeneous lesion with inaccurate limits in the gallbladder affecting segment IVb of the liver, in addition to lymphadenopathy in the hepatic hilum. A cholecystectomy with resection of segments IV-B and V of the liver (radical cholecystectomy) and hepatic hilar lymphadenectomy were performed. Anatomopathological examination and immunohistochemistry confirmed a primary mixed adenoneuroendocrine carcinoma of the gallbladder. The patient received adjuvant chemotherapy and radiotherapy; however, after the patient reported experiencing low back pain, a CT was performed, revealing retroperitoneal metastasis, and the radiotherapy was interrupted. Currently, the patient has a stable disease, following a protocol of 5-Fluorouracil and somatostatin, and she reports having low back pain of low intensity. CONCLUSIONS This is the 24th gMANEC case reported in the literature. The tumor was successfully resected; however, the patient presented retroperitoneal metastasis 6 months after surgery, despite combined adjuvant therapy.

Gastrointestinal stromal tumor of the excluded stomach after Roux-en-Y gastric bypass: A case report and literature review.

BACKGROUND: Gastric cancer is an extremely rare condition to occur after bariatric surgery, and most of the reported cases are adenocarcinomas. Regarding gastrointestinal stromal tumors (GISTs), there are only two reported cases occurring after bariatric surgery (one after gastric banding and the other following Roux-en-Y gastric bypass (RYGB)). CASE PRESENTATION: A 48-year-old woman with previous history of obesity and type 2 diabetes, treated with a Roux-en-Y gastric bypass 2 years earlier, was referred to our center due to complains of diffuse abdominal pain and distension associated with asthenia. Magnetic resonance imaging showed a cystic-solid mass located in the right hypochondrium, measuring 19.5 × 13.5 × 16 cm, suggesting the diagnosis of a retroperitoneal tumor. Based on these findings, a laparotomy, evidencing that the larger cystic-solid tumor was originating from the excluded stomach post-RYGB. The gastrectomy of the excluded stomach was performed aside with a conventional cholecystectomy. Histopathology and immunohistochemistry confirmed to be a gastric GIST with epithelioid cells. Currently, 12 months after surgery, the patient presents no signs of recurrence. CONCLUSION: This is the second case of gastric GIST occurring after RYGB to be reported in the literature.