Abstract
Essential thrombocythemia (ET) is a Philadelphia chromosome (Ph)-negative myeloproliferative neoplasm. It is characterized by thrombocytosis and megakaryocytic hyperplasia of the bone marrow with JAK2V617F mutation. Iron-refractory iron deficiency anemia (IRIDA) is an autosomal recessive disorder, which is mainly characterized by iron deficiency anemia not responding to oral iron intake, but partially responding to parenteral iron therapy. Recently, it has been shown that IRIDA has stemmed from mutations in the gene TMPRSS6, which encodes a transmembrane serine protease (matriptase- 2) expressed by the liver. Renal cell carcinoma (RCC) accounts for 2–3% of all cancers. As the most common solid lesion in the kidneys, it represents approximately 90% of all renal malignancies. Approximately 30% of patients with symptomatic RCCs seem to display paraneoplastic syndromes. The symptom that may result from erythrocytosis is the most wellknown paraneoplastic hematological event. Here, we report a patient who presents with coexistence of RCC and thrombocytosis, which hasn’t been caused by hormonal factors that are produced in tumor cells. This patient has been therefore diagnosed with ET. The patient who was expected to display RCC with polycythemia, conversely present with IRIDA.