Central Retinal Vein Occlusion in Acute Promyelocytic Leukemia and Heterozygosis’ for Factor V Leiden and Methylentetrahydrofolate Reductase (MTHFR) Gene Mutations

We present a 45-year-old man with low-risk acute promyelocytic leukemia in whom thrombosis of central retinal vein occurred a year after establishing diagnosis, during molecular remission while being on maintenance therapy with all-trans-retinoic acid, purinethol and methotrexate. As major risk factors leading to central retinal vein occlusion (CRVO) we identified heterozygosity for factor V Leiden (G1691A) and methylentetrahydrofolate reductase (C677T) gene mutations. Moreover, hyperhomocysteinemia of moderate degree, low plasma folate level and arterial hypertension appeared contributory factors. Hyperhomocysteinemia could be attributed to both methylentetrahydrofolate reductase (C677T) gene mutation and methotrexate administration. Screenings for inherited and acquired thrombophilia are mandatory for all patients with unusual thrombotic events such as CRVO whether they have history of leukemia or not.