CD99 and histiocytoma, Angiomatoid fibrous: Other entities in this genetic tumor spectrum such as AFH possess defining morphological (e.g., syncytial epithelioid or spindle cells in fascicular growth associated with variable aneurysmal/angiomatoid changes and lymphoid cuffs) and immunophenotypic (variable expression of cytoplasmic CD99, desmin, EMA, and ALK) features.