Extreme Thrombocytosis: A Unique Constellation of Reactive Thrombocytosis, Iron Deficiency Anemia and Atypical Celiac Disease

Reactive thrombocytosis refers to elevated platelet count in the absence of a myeloproliferative or myelodysplastic syndrome and is secondary to a medical or surgical condition. Extreme thrombocytosis (>1000) is unlikely to be autonomous in origin and an underlying reactive process should be strongly suspected. A 22 year old apparently healthy male presented with fatigue of five months duration. Labs showed marked hypochromic microcytic anemia with hemoglobin of 5 g/dL, extremely high platelet count of 1600 x 10 and undetectable ferritin. Upper and lower GI scopes failed to reveal any source of bleeding. Ultrasound abdomen revealed mildly enlarged spleen. Besides markedly increased megakaryopoesis, erythropoesis and low iron stores; bone marrow biopsy did not reveal any myelodysplasia. Patient was transfused 4 units of Packed RBC with rapid improvement of hemoglobin and platelet count within one week. Villous atrophy on duodenal biopsy and elevated tissue transglutaminase antibody levels confirmed diagnosis of celiac disease. Patient was started on iron supplements and gluten free diet. Follow up in 3 months revealed completely normal hemoglobin, ferritin level and platelet count. Extreme thrombocytosis should raise suspicion for a secondary cause rather than a primary myeloproliferative disorder. Iron deficiency anemia, a relatively rare but benign cause should be strongly considered in work up of reactive thrombocytosis. Atypical forms of celiac disease can be relatively asymptomatic. If clinical suspicion is high serum antibody assay and intestinal biopsy should be considered. The case illustrates rare constellation of extreme thrombocytosis from iron deficiency anemia in an otherwise asymptomatic celiac disease patient.