Delayed diagnosis of pediatric Langerhans' cell histiocytosis: case report and retrospective review of pediatric cases seen at Mayo Clinic.

Langerhans' cell histiocytosis is a disease of the dendritic histiocytes with a wide variety of clinical manifestations. This report describes a boy with Langerhans' cell histiocytosis who presented with primarily neurologic and endocrinologic findings, without pain. The diagnosis of Langerhans' cell histiocytosis was not made until 10 years after symptom onset. The pathology database at Mayo Clinic was searched for cases of Langerhans' cell histiocytosis between 1985 and 1999 under 19 years of age (65 children), and information regarding clinical presentation was abstracted. Database review found a range of 1 day to 156 weeks (mean 13.8 weeks) from symptom onset to diagnosis. No other patients with primarily neurologic symptoms were found. The diagnosis of Langerhans' cell histiocytosis was made significantly sooner after onset if pain was present (chi-square = 19.1, P < .001, two-tailed, phi coefficient 0.54). Our findings indicate that neurologic manifestations of Langerhans' cell histiocytosis are rare, and the combination of diabetes insipidus, ataxia, skin rash, or osseous pain should alert the clinician to the possibility of Langerhans' cell histiocytosis and avoid delayed diagnosis.