Mixed adenoneuroendocrine carcinoma of the liver: A rare case report

A 55-year-old woman presented with chest and back pain of unknown cause. Contrast-enhanced computed tomography revealed two low-density tumors, sized 4.6 and 4.4 cm, in the hepatic caudate and left inner lobes, respectively. There are multiple enlarged lymph nodes around the abdominal aorta, hepatogastric ligament and gastrosplenic ligament. At the same time, there were multiple enlarged lymph nodes between the portal vein and the vena cava. Upper gastrointestinal endoscopy revealed chronic non-atrophic gastritis and esophagitis (grade B). Endoscopic examination of the lower digestive tract revealed polyps of the colon, diagnosed as tubular adenomas following biopsy and histopathological examination. The patient underwent left three hepatic resection (including left inner lobe, left outer lobe and right anterior lobe resection), abdominal lymph node dissection, right liver tumor radiofrequency ablation, hepatic caudate lobe resection, intestinal adhesion release, vena cava formation, portal vein repair and hilar cholangioplasty. The pathological examination of the resected specimens revealed intrahepatic bile duct carcinoma and hepatic parenchymal neuroendocrine tumor (NET). In addition, liver solid portions consisted of tumor cells with characteristic salt-and-pepper nuclei. Immunohistochemical examination revealed expression of the neuroendocrine marker synaptophysin in this solid component, confirming the diagnosis of NET. Furthermore, the MIB-1 proliferation index of the NET was higher compared with that of the adenocarcinoma, and lymph node invasion by the NET component was detected, indicating a neuroendocrine carcinoma (NEC, or NET G3). The diagnosis of mixed adenoneuroendocrine carcinoma of the liver was confirmed based on the World Health Organization 2010 criteria. Taking into consideration the patient's poor general condition, only symptomatic supportive treatment was administered postoperatively, without chemotherapy. Contrast-enhanced computed tomography at 45 days postoperatively revealed disease progression, with metastases in the liver stump, abdominal lymph nodes, spine and pelvis. The patient remained on symptomatic supportive treatment and succumbed to disease progression 3 months after surgery.