This paper presents a case study of a patient with an extensive radicular cyst in mandible. Radicular cysts that are particularly extensive should be differentiated from various types of cysts, benign tumors – especially ameloblastomas, cyst alike lesions, some forms of fibrous dysplasia or central granuloma. In majority of cases those lesions are asymptomatic, therefore periodic radiological diagnostics of patients, especially those with general burden, are advisable, in order to exclude the potential outbreaks of infection. Based on available literature, full radiological, clinical, histopathological diagnostics of the lesion, in the later stage a non‑standard therapeutic procedure was applied. Enucleation treatment was suspended until proper bone reconstruction, which allowed to avoid massive surgery.