Langerhans Cell Histiocytosis

Epidemiology

Langerhans cell histiocytosis (LCH), previously known as histiocytosis X, is believed to be an autoimmune disorder. There is no obvious sex predilection although familial incidence has been reported. The disseminated form of this disease (Letterer-Siwe disease) is found in infants and young children, whereas the localized form (eosinophilic granuloma) is found mainly in older children and young adults. Between these forms is an intermediate group called Hand-Schüller-Christian disease. LCH with involvement of the thyroid gland is uncommon. Until 1991, there were only 10 such patients reported in the English literature. An English literature search through 1995 revealed a further six reports.

Clinical Findings

Patients with thyroid involvement usually have associated multiple organ involvement such as lung and orbital lesions. These patients may also have severe seborrhea or maculopapular rashes. Respiratory embarrassment as a result of thyroid gland enlargement and tracheal compression is rare. Diabetes insipidus is the most common endocrine abnormality in LCH. Most patients with thyroid involvement (80%) appear to have concomitant diabetes insipidus. This is much higher than the 20 to 50% generally reported in LCH.