Large Bowel's tumor of unclear histogenetic origin from the group of neuroendocrine tumors with life-threatening hemorrhage and hemorrhagic shock

Introduction. Neuroendocrine neoplasms (NENs) of the gastrointestinal tract (GIT) are slow-growing and rare tumors with different clinical, histological, and biological characteristics with an increased incidence in recent years. Most of them are indolent and colonic NENs are rare among all GIT-NENs. Compared to colorectal adenocarcinoma neuroendocrine tumors of the colon and sigmoid colon are uncommon. Case outline. We present a 25-year-old female patient, who was admitted to our department in hemorrhagic shock due to life-threatening bleeding from a tumor on the sigmoid colon, and after unsuccessful endoscopic hemostasis during colonoscopy. The complaints started the day before admission to the ward with hematochezia. The patient had no complaints before that. Emergency operation and colon resection with terminal colostomy were performed. Pathohistological and immunohistochemical analysis of the tumor showed unclear histogenetic origin from the group of neuroendocrine tumors. Conclusion. Regardless of the asymptomatic period of the disease, these tumors can cause severe bleeding as the first symptom, which can be life-threatening.