Carcinoid Tumors

Carcinoid tumors were first described over 100 years ago by Lubarsch, who found multiple tumors in the distal ileum of two patients at autopsy.1 The term karzinoide was used by Oberndorfer in 1907 to describe similar tumors that appeared to behave in a more indolent fashion than typical adenocarcinomas.2 Carcinoid tumors have subsequently been reported in a wide range of organs but most commonly involve the lungs, bronchi, and gastrointestinal tract.BiologyCarcinoid tumors are thought to arise from neuroendocrine cells. They are characterized histologically by positive reactions to silver stains and to markers of neuroendocrine tissue, including neuron-specific enolase, . . .