We hereby report a case of a 55-year-old woman, with complaints of sudden onset outward protrusion of left eye progressing over 2 months, along with pain and loss of vision. Visual acuity in the affected eye was light perception only. On imaging, a well-defined solitary cystic lesion was noted in the retrobulbar space, which showed no enhancement on contrast-enhanced MRI. We performed fluid aspiration from the cyst under negative pressure and injected bleomycin as a sclerosant, without attempting a surgical excision. The proptosis reduced visibly, and after a week, visual acuity improved to finger counting at 1 m. At the 6 months follow-up, the patient did not show any recurrence of proptosis. This report highlights the importance of sclerosant therapy without the need for surgical excision in managing macrocystic lymphangiomas in adult age group.