Background: Thyroid cancer is the most common endocrine cancer, with an increasing incidence around the world in the last three decades. The increased risk of secondary cancer is associated with a genetic predisposition or radioactive iodine used in the treatment.
Case Report: A 65-year old male patient was operated on for thyroid papillary cancer. He received radioactive iodine on two occasions postoperatively. After six years, he presented with malaise and fatigue with leukocytosis and eosinophlilia. The physical examination revealed inguinal lymphadenopathies and splenomegaly, after examining the bone marrow and lymph node biopsies, he was diagnosed with eosinophilic myeloproliferative neoplasia and T-cell lymphoblastic leukaemia/lymphoma.
Conclusion: Leukaemia and other haematological malignencies may develop after radioactive iodine treatment. Patients with radioactive iodine ablation history should be monitored for a long time.