The bone defects of the cranial vault encompassed rare malformations including acalvaria, hypocalvaria, acrania, hypocrania, anencephaly and exencephaly. They are also described in some pathological entities such as aplasia cutis congenita of the scalp. We report an unusual case of cephalic malformation which combine defects of the skin, the dura mater, and the bones of the vault, with a malformation of the central nervous system. This unique case emphasizes a problem of nosological definition between the terms mentioned above. acalvaria, the acrania, the hypocalvaria and the aplasia cutis congenita. Thus, herein, we proceed to a literature review of bone defects of the skull and their differential diagnosis.