Vol. 5, Issue 1, Part A (2023)

A 10-year-old boy was referred to our hospital, for a one-week history of a rapidly progressing left eye proptosis, preceded by right eye conjunctival lesion that appeared a few weeks prior the onset of proptosis, and was unsuccessfully managed as conjunctivitis. Upon presentation, imaging showed enlargement of the left superior rectus muscle without invasion of adjacent structures, associated with bilateral level II cervical lymphadenopathies. A diagnosis of rhabdomyosarcoma with lymphatic metastasis was suspected. Nevertheless, an incisional biopsy of the right conjunctival lesion enabled establishing the diagnosis of orbital myeloid sarcoma with monocytic differentiation. Upon diagnosis, chemotherapy was initiated with subsequent regression of the lesions. However, due to the unfavorable socioeconomic status of the patient, the management process was not completed in a timely manner, leading to permanent unilateral visual loss due to optic nerve compression by the rapidly expanding mass.