Acute megakaryoblastic leukemia in Down syndrome: orbital infiltration.

PURPOSE: To describe an uncommon ocular presentation of acute megakaryoblastic leukemia in a child with Down syndrome.

METHOD: Case report. Initial manifestation of disease was bilateral proptosis with secondary exposure keratitis caused by leukemic infiltration of the orbits.

RESULTS

Bone marrow biopsy and immunophenotyping established the diagnosis of acute megakaryoblastic leukemia (FAB-M7). The leukemia was treated successfully with chemotherapy, with resolution of proptosis. The patient remained in remission more than 1 year after cessation of treatment.

CONCLUSIONS

Bilateral proptosis can be a presenting sign of acute megakaryoblastic leukemia, a malignancy associated with Down syndrome.