Persistent Fever, Mediastinal Mass in a 5-year-old Boy

Abstract

<P>This 5-year-old boy was transferred from an outside hospital for evaluation of persistent fever and a mediastinal mass. He was in his usual state of good health until 2 days prior to admission, when he developed fever, abdominal pain, chest pain, vomiting, and diarrhea. There were no complaints of dyspnea, cough, orthopnea, or fatigue. He was admitted to an outside hospital for treatment of gastroenteritis and dehydration. At the time of admission, laboratory findings included hemoglobin 7.2 g/dL, MCV 59, white blood cell count 13,000/mm<sup>3</sup> with 71% polymorphonuclear cells, 21% lymphocytes, 7% monocytes; platelet count 160,000/mm<sup>3</sup>. Because of the microcytic anemia, a lead level was obtained, which was 32 mcg/dL. While looking for lead chips in the abdomen, x-ray revealed a left lower lobe infiltrate. Two days later, a chest x-ray demonstrated cardiomegaly. This finding prompted echocardiography, which revealed a moderate to severe circumferential pericardial effusion. Ultimately, 220 cc of serosanguineous pericardial fluid was removed. The cell count had 70,000 red blood cells, 3,000 white blood cells that were 70% neutrophils, and 12% lymphocytes. Acid-fast bacterial stains were negative. The pericardial fluid glucose was 76 mg/dL, and protein was 5 g/dL. The pericardial fluid culture was negative. Several days later, follow-up echocardiogram revealed an echogenic density in the wall of the right atrium at the superior vena cava-right atrial junction. A cardiac magnetic resonance image (MRI) demonstrated a 6.5 × 3.0 cm mass in the pericardial space, abutting the anterolateral aspect of the right atrium.</P> <H4>Key Learning Points</H4> <OL> <LI>Anemia of chronic inflammation is generally normocytic, but may be microcytic at times.</LI> <LI>The normal age groups in which iron deficiency is seen are between 9 to 24 months and in the early teenage years, particularly in menstruating young women. Outside these age ranges, physicians must consider an alternate etiology of iron deficiency, such as occult gastrointestinal blood loss or iron malabsorption.</LI> <LI>Immune myofibroblastic tumors are a spectrum of proliferative lesions that range from a benign, reactive process to a true malignancy. They often present with high fevers and refractory anemia as a result of prostaglandin release.</LI> </OL> <H4>ABOUT THE AUTHOR</H4> <P>Dr. Listernick is Professor of Pediatrics at Feinberg School of Medicine, Northwestern University, and Director of the Diagnostic and Consultation Service, Division of General Academic Pediatrics, Children’s Memorial Hospital, Chicago, IL.</P>