Karzinoide
Karzinoide, also known as carcinoid tumors, are a subset of neuroendocrine tumors that originate from neuroendocrine cells, most often enterochromaffin cells in the gastrointestinal tract or in the lungs. Most karzinoide tumors are slow-growing and can be either functional, secreting hormones such as serotonin, or nonfunctional.
Common sites include the appendix, small intestine (jejunum and ileum), and rectum, with other gastrointestinal sites
Clinical features depend on secretion. Functional tumors may cause carcinoid syndrome, characterized by flushing, diarrhea, abdominal
Diagnosis is based on histology showing neuroendocrine differentiation (markers such as chromogranin A and synaptophysin) and
Treatment depends on stage and grade. Localized disease is usually managed by surgical resection. In advanced
Prognosis varies by site and grade; appendiceal carcinoids often have excellent outcomes, while midgut and pancreatic