A two-year-old girl is brought to your office with a wide spread skin rash involving the scalp, the face, the trunk, groin and the buttocks. She was treated for seborrheic dermatitis by their pediatrician but the rash did not go away. In the review of systems, the mother reports that the patient has an ear infection that ‘is not going away even after using many antibiotics’. On physical examination, you find a rash with yellow-brown papules topped with scale and crust. In some areas, the papules coalesced to form an erythematous, weeping eruption resembling seborrheic dermatitis. She has hepatosplenomegaly and cervical lymphadenopathy. Suspecting a systemic disorder, you ordered some laboratory tests and imaging studies. Radiographs revealed lytic bone lesions in the skull and long bones. The electron microscopy of a cell in a bone lesion revealed the presence of tennis-racket-shaped granules in the cytoplasm. The cytogenetic study revealed BRAFV600E mutation. Of the following, the cells in this disorder express which markers when examined with immunohistochemical stains?
