A 3-year-old boy is brought to the physician for persistent left arm pain the past two weeks. Physical examination shows no abnormalities. X-ray and MRI are performed and show an osteolytic soft tissue mass. Biopsy shows an infiltration of sheet-like pale eosinophilic cells with bean-shaped nuclei. The cells test positive for CD1a. Electron microscopy shows Birbeck granules. The type of cell most likely involved in this patient’s condition normally has which of the following functions?
Activation of CD40
Antigen presentation
Bone formation
Bone resorption
Opsonization and phagocytosis
