Pancreatic islets Pancreatic islets The pancreatic islets or islets of Langerhans are the regions of the pancreas that contain its endocrine (hormone-producing) cells, discovered in 1869 by German pathological anatomist Paul Langerhans. The pancreatic islets constitute 1 to 2% of the pancreas volume and receive 10–15% of its blood flow. The pancreatic islets are arranged in density routes throughout the human pancreas, and are important in the metabolism of glucose. There are about 3 million islets distributed in the form of "density routes" throughout the pancreas of a healthy adult human, each of which measures an average of about 0.1 mm (109
Langerhans cell histiocytosis called "eosinophilic granuloma" (an older term which is now known to be a misnomer), is a slowly progressing disease characterized by an expanding proliferation of Langerhans cells in various bones. It can be a monostotic (involving only one bone) or polyostotic (involving more than one bone) disease. It typically has no extraskeletal involvement, but rarely an identical lesion can be found in the skin, lungs, or stomach. When found in the lungs, it should be distinguished from Pulmonary Langerhans cell hystiocytosis—a special category of disease most commonly seen in adult smokers. This primary bone involvement helps to differentiate eosinophilic granuloma