Langerhans cell histiocytosis in children diagnosed by fine-needle aspiration

BACKGROUND: Langerhans cell histiocytosis (LCH) is a rare intricate pediatric neoplasm with varied clinical manifestations and multiple treatment modalities. AIM: To study the cytological features of LCH and the differential diagnoses on fine-needle aspiration (FNA). MATERIALS AND METHODS: FNA was performed using a 23-gauge needle fitted to a 10 mL syringe mounted on syringe holder. LCH was diagnosed on FNA smears in seven cases confined to the head and neck region, which included three cases of lymphadenopathy, three cases of scalp swelling, and one case of orbital swelling. RESULTS: The age of the patients ranged from 25 days to 11 years and male-to-female ratio was 1:1.3. Clinically, the diagnoses suggested were tuberculosis, inflammatory lesion, abscess, and malignancy. The cytologic findings included high cellularity, isolated Langerhans cells (LCs) with prominent nuclear indentation, grooves and abundant vacuolated cytoplasm, multinucleated giant cells, eosinophils, and lymphocytes. Areas of necrosis were noted in one case. Histopathology, along with positive S-100 immunohistochemistry, confirmed the diagnosis of LCH. CONCLUSIONS: LCH is a rare disease occurring predominantly in children and can be diagnosed with ease on FNA cytology by the presence of characteristic Langerhans cells. The S-100 positivity aids in suggesting a diagnosis of LCH.