Extramedullary hematopoiesis is common in chronic hemolytic anemias such as pyruvate kinase deficiency. It is commonly associated with hepatosplenomegaly or lymphadenopathy; however, it can rarely also present as a mass in the chest, abdomen, or paraspinal region. Here, we present a case of an adult patient with pyruvate kinase deficiency and history of splenectomy. He presented with sepsis and brisk leukocytosis secondary to pneumonia and was also found to have diffuse intraabdominal lymphadenopathy along with a paravertebral mass. The radiological findings raised concerns for a systemic lymphoproliferative disorder and there was a suggestion for further workup with a biopsy. However, given the patient's underlying pyruvate kinase deficiency, we hypothesized that the paravertebral mass is likely a result of extramedullary hematopoiesis in the setting of bone marrow stress from infection and ongoing hemolysis; thus, we decided against biopsy. Repeat imaging six weeks after the presentation showed resolution of the paravertebral mass, which consolidated our hypothesis. This highlights the importance of avoiding invasive diagnostic procedures in asymptomatic patients with chronic hemolysis who may present with diffuse mass lesions.
Keywords: extramedullary hematopoiesis; infection; intraabdominal lymphadenopathy; medistinal mass; paravertebral mass; pyruvate kinase deficiency.