Introduction: Despite intensive investigation, the pulmonary lesions of Langerhans cell histiocytosis can sometimes prove difficult to yield a diagnosis of this potentially multi-focal disease.
Case report: We report the case of a sixteen year old woman, who presented with a hypothalamo-hypophyseal mass associated with endocrine clinical signs, dyspnoea, and micro-nodular pulmonary lesions on computerised tomography. A Langerhans cell histiocytosis was initially suspected, but then thought unlikely in the light of negative pulmonary investigations and spontaneous regression of the pulmonary lesions. However, an increase in the size of the cerebral mass prompted a brain biopsy finally confirming the diagnosis of Langerhans cell histiocytosis.
Conclusions: This case report identifies a possible dissociation between the clinical courses of cerebral and pulmonary Langerhans cell histiocytosis, and confirms the usefulness of extra-thoracic biopsies in making a diagnosis on the disseminated form of the disease.