Cytological diagnosis of Langerhans cell histiocytosis with cutaneous involvement
A 4 year old male child presented with diffuse cervical swelling on the left side of the neck since 2 months. There were multiple eczematous lesions seen over the swelling. On examination, multiple cervical lymph nodes were palpable measuring 0.8 × 0.8 to 1.2 × 1.5 cm on the anterior neck on both the sides of the neck. They were firm, tender and slightly mobile. Patient also had history of left ear discharge since 2 weeks. He had no fever or loss of weight. Liver and spleen were not palpable. There was no history of Koch's contact.\nOn investigation his hemoglobin was 11.5 g/dL. Total leukocyte count was 12,080 with differential count showing 45% neutrophils, 37% lymphocytes, 15% monocytes and 3% eosinophils. Platelet count was normal. The Mantoux test was negative. The bone marrow biopsy was unremarkable. Skeleton X-ray survey revealed no abnormality. Positron emission tomography (PET) scan showed conglomerate nodal mass in left II, III, II/V level and left supraclavicular nodal mass extending upto superior mediastinum and left chest wall. There were no lytic lesions seen in the skeleton system. Thyroid was normal.\nThe patient was referred for FNAC. FNAC from diffused selling over left supraclavicular region yielded hemorrhagic whitish aspirate. Ethanol fixed smears and air dried smears were prepared and stained with Papanicolaou and Giemsa stains respectively. Cytological smears were cellular and showed numerous atypical histiocytes singly and in loose cohesive clusters. These histiocytes were binucleate, multinucleate with abundant dense cytoplasm and eccentric vesicular nuclei [Figure -]. The nuclei showed characteristic intranuclear pseudoinclusions, prominent nuclear indentations and grooves (with a kidney or coffee bean appearance) []. The background showed lymphocytes, neutrophils and few eosinophils []. The presumptive diagnosis of Langerhans cell histiocytosis was given.\nThe differential diagnoses entertained were Hodgkin's lymphoma and Langerhans cell histiocytosis. Subsequently biopsy was done.\nThe biopsy showed sheets of atypical histiocytes with grooves with polymorphous inflammatory cells comprising of eosinophils, neutrophils, lymphocytes in background. There was no necrosis, and no mitosis []. The immunohistochemistry was performed. On immunohistochemical staining, S-100 and CD1a were diffusely positive in all the atypical histiocytes []. Desmin and ALK-1 were negative. The final diagnosis of Langerhans cell histiocytosis was given (Low risk).[]\nThe patient was treated with vinblastine, etoposide and prednisolone. After 4 months, the swellings decreased and all the eczematous lesions healed completely.