The paper describes a rare case of aneurysmal bone cyst in a 2-year- and 4-month-old patient, which is uncharasteristic of this pathology. The peak incidence of aneurysmal bone cyst is in the second decade of life and in the second half of the first decade (the median incidence is at 13 years of age according to the WHO). Its typical site is the cuneiform bone (its greater wing with a spread into to the orbit, maxillary sinus, nasal cavity, and intracranially and extradurally). The clinical picture corresponded to the location of a pathological process and included facial asymmetry with swelling in the left zygomatic-and-buccal region and in the parotid region, as well as palpebral fissure swelling, marked left-sided exophthalmos, mild limited ectad aversion of the eyeball, lacrimation, anisocoria, sluggish pupil, reduced vision in the left eye, partial left optic nerve atrophy, and left hard palate bulging. Neuroimaging revealed a sizable osteolytic focus with irregular margins, heterogeneous content, and a bone density shell 2—3 mm thick, as well as progression and a short-term (8-month) history, which together with the contradictory results of resection biopsy at the stages of treatment could suggest that the patient had a neoplastic process, which was an indication for surgery. Total resection was successfully performed via the orbitozygomatic approach.