Contrast-Enhanced Ultrasonography Features of Extramedullary Hematopoiesis Presenting as a Presacral Mass: an Update of the Literature

Introduction

Extramedullary hematopoiesis (EMH) in post-fetal life is a compensatory mechanism that may occur in chronic anemias in order to maintain the circulatory demand in conditions of hyperactive, depleted, or infiltrated bone marrow. EMH can arise from pluripotential stem cells throughout the body. Reported sites of extraosseous erythropoietic tissue masses primarily include liver and spleen. The occurrence of non-hepatosplenic localizations is rare and most cases affect the spinal column, mainly at thoracic level (Koch C et al. Mayo Clin Proc 2003; 78: 1223 – 1233). More rarely, breast tissue, dura mater, adipose tissue, skin and numerous other sites may be involved (Saghafi M et al. Eur J Intern Med 2005: 16: 596 – 597). To date, imaging features of EMH masses have been described referring to conventional ultrasound, CT and MRI but so far, CEUS patterns have not been reported except for the liver (Bartolotta TV et al. Eur Radiol 2005; 15: 1643 – 1649). We here present a 65-years old patient affected by thalassemia intermedia and focal extramedullary hematopoiesis presenting as a pre-sacral mass diagnosed with multimodal imaging studies.