A 2-year-old boy has recurrent otitis media, a seborrhea-like scaly rash over the scalp and trunk, and multiple punched-out lytic lesions of the skull on radiography. Biopsy of a scalp lesion shows cells positive for CD1a and S100 with tennis-racket-shaped cytoplasmic inclusions on electron microscopy. Which complication should be specifically screened for?

• A Optic glioma
• B Adrenal insufficiency
• C Bilateral nephromegaly from infiltration
• D Diabetes insipidus from pituitary stalk involvement ✓

Explanation

The triad of lytic skull lesions, seborrheic dermatitis-like rash, and otitis media with CD1a-positive Birbeck granule-containing histiocytes establishes Langerhans cell histiocytosis. Posterior pituitary or hypothalamic involvement causes diabetes insipidus, classically presenting as polyuria and polydipsia, and is the multisystem complication most emphasized in exams. Adrenal failure and nephromegaly belong to disseminated neuroblastoma and congenital adrenal hyperplasia respectively, while optic glioma is linked to neurofibromatosis type 1.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.