Authors present the possibilities of different examination methods in cases of intraocular expansions and specific diagnostic methods to determine the actual etiology of the intraocular process in the posterior segment in particular. Of special concern to authors are cases, as is e.g. vitreous hemorrhage, in whose the standard examination methods are not useful. Pars plana vitrectomy with intraocular biopsy of the tissue for histological and cytological examination is very effective method to determine the proper diagnosis. The case report concerns with a 58 years old woman with vitreous hemorrhage and suspect tumor-like lesion, diagnosed by means of ultrasound examination. The pars plana vitrectomy revealed extensive preretinal organized hemorrhage with intravitreal hemorrhage. Samples for cytological examination were taken.

        Key words: intraocular tumor, pars plana vitrectomy, differential diagnosis