[Cranial osteomas of atypical localization]

Osteomas have a very characteristic localisation and frequency of occurrence. Based on a representative materials the authors present literature review in which the sequence of occurrence of osteomas in paranasal sinuses is described. A very rare occurrence of osteomas out of the paranasal sinuses is stressed and the hypothesis of development of osteomas in the sinuses and latter migration of osteomas from sinuses to nasal cavities or orbit is mentioned. Three cases of untypical size and localization of osteomas are presented, in two cases the tumors have develop primary outside the paranasal sinuses and in one case the osteoma was present in both frontal sinuses and in the ethmoid labyrinth.