C96.6: Unifocal Langerhans-cell histiocytosis

Unifocal Langerhans-cell histiocytosis is a rare type of disease that affects specific types of cells in the body called Langerhans cells. These cells, which are part of the immune system, usually help the body fight infections. However, in this condition, the Langerhans cells start to grow too much, leading to the formation of tumors. Interestingly, despite being named "unifocal", this disease can affect almost any part of the body, but it's commonly found in the bones, particularly in the skull or long bones of the arms or legs. When this happens, patients may experience pain, swelling, and sometimes even fractures. Additional symptoms depend on the part of the body affected. For instance, if the disease involves the lungs, patients may have trouble breathing, and if it involves hormone-producing organs, various hormonal imbalances may occur. Despite its potential severity, this disease varies considerably in its progression, ranging from mild and slow-growing to more aggressive forms.