Langerhans cell histiocytosis: a diagnostic dilemma

Langerhans cell histiocytosis encompasses a diverse number of idiopathic conditions which can involve multiple body systems.1 It is characterized by bone marrow-derived Langerhans cell proliferation and can affect many body systems, including: bone, lung, skin, mucous membranes, lymph nodes and the liver. The lesions can be solitary or widespread.

LCH includes a group of disorders which are classically described as being of one of three forms with distinct clinical presentations. The eosinophilic granuloma normally presents as a solitary slowly progressing lesion in the bone, lungs or stomach, often found as an incidental radiographic finding typically in young adults. It tends to be more benign in nature and solitary, responding well to conservative local treatment. Letterer-Siwe disease, in contrast, is a multi-system rapidly progressing form of the condition in very young children, which is treated with chemotherapy, but has a very poor survival rate. The final condition which makes up the disease triad is Hand-Schüller-Christian disease which is a multifocal eosinophilic granuloma with multiple bony lesions, exophthalmos and diabetes insipidus. This typically affects young children, on average between 2–5 years, and lies somewhere intermediate to the other forms of LCH in terms of prognosis and severity. Disease onset can occur several years before symptoms and signs lead to a diagnosis.