Squash cytology of langerhans cell histiocytosis of sellar region

Langerhans cell histiocytosis (LCH) is a systemic disease, which usually involves the skeleton and skin of children with occasional involvement of the central nervous system (hypothalamo–pituitary axis). We report the case of a 16-year-old male with a space-occupying lesion (SOL) in the sellar region and diabetes insipidus. However, no systemic abnormality was noted. A clinical diagnosis of pituitary adenoma was given. However, on intraoperative consultation by squash smears, cells with nuclear grooves and few eosinophils were seen. Hence, a differential diagnosis of LCH was also given, which was confirmed by histopathology and immunohistochemistry. Hence, as a matter of fact, LCH should be considered as one of the rare differential diagnoses of SOL of sellar region.