This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
[{'content': "A 2 – year – old child comes with discharge, seborrheic dermatitis, polyuria and hepatosplenomegaly. Which of the following is the most likely diagnosis : \nSelect and explain. \nA. Leukemia, B. Lymphoma, C. Langerhan's cell histiocytosis, D. Germ cell tumour", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Seborrheic dermatitis, polyuria, hepatosplenomegaly and discharge suggest the diagnosis of Langerhans cell histiocytosis.\nClinical manifestations of Langerhans cell histiocytosis :\n\nIt has diverse clinical features. These are\n\n1. Skeletal involvement :\n\nIt is seen in 80% of cases (75% cases present with solitary lytic lesion).\nSkull is the most common site of involvement (Presents. with solitary lytic lesion).\nInvolvement of the spine leads to the collapse of vertebral body and compression of spinal cord.\nIn flat long bones, the lesion is osteolytic.\nInvolvement of mastoid bones leads to chronically infected ears.\n\n2. Skin involvement :\n\nIt is seen in 50% of patients.\nIt usually manifests as seborrheic dermatitis of scalp or diaper region.\n\n\n3. Hepatosplenomegaly :\n\nSeen in 20% of patients.\nManifests as jaundice and ascites.\n\n\nLocalized or disseminated lymphadenopathy.\nExophthalmos :\n\n\nIt is often B/L and is caused by retroorbital accumulation of granulomatous tissue.\n\nPulmonary Infiltrates :\n\nSeen in 10-15% of patients.\nThe lesion consists of nodular infiltrates or diffuse fibrosis.\n\n\nEndocrine → Hypopituitarism, Hypothyroidism, Diabetes insipidus.\nSystemic manifestations\xa0:\n\n\nUsually seen in patients affected severely.\nThese include fever, weight loss, malaise, irritability.\nRemember these two uncommon but serious manifestations of LCH.\n\n\nCirrhosis d/t hepatic involvement.\nAtaxia and dysarthria d/t CNS involvement.', 'role': 'assistant'}]