Pancytopenia secondary to hypothyroidism in a 13-year-old male child

Abstract

Thyroid hormones have a crucial role in erythropoiesis and metabolism. They enhance erythropoiesis through hyper proliferation of immature erythroid progenitors and increase secretion of erythropoietin by inducing erythropoietin gene expression. Thyroid dysfunction has various effects on blood cells such as anaemia, erythrocytosis leukopenia, thrombocytopenia, and in rare cases pancytopenia. The exact pathogenesis of anaemia secondary to hypothyroidism is not precisely explained but appears to reflect an adaptation to decreased tissue oxygen requirements resulting from a decrease in the basal metabolic rate. In reviewing the literature, there have been few previously reported cases of hematological abnormalities due to hypothyroidism, all of them concerning adults. In this article, we describe a rare case of pancytopenia secondary to hypothyroidism in a 13-year-old male child and its partial reversal after thyroid hormone replacement. Hypothyroidism should be considered in patients with unexplained pancytopenia. Further studies are needed to determine the exact underlying disease mechanism.