Ultrasound criteria of splenomegaly in patients with fever and infectious mononucleosis

Ultrasound examination of the spleen is a promising approach allowing to accurately determine its normal size in various age groups as well as in pathological conditions. Objective – to evaluate spleen size changes in patients with febrile state and infectious mononucleosis. Ultrasound morphometric examination of the spleen was carried out in patients with febrile state (group “A”, n = 22) and infectious mononucleosis (group “B” n = 24) by assessing organ echo structure, contour clarity, and its uniformity. Morphometric data allowed to measure spleen weight and various coefficients by using the method proposed by Vozgoment et al. for calculating spleen weight (Wt) with formula: Wt = 0.34 * L2h, where L – the length of the spleen, h – the thickness of the spleen (cm); spleen weight coefficient (SWC) by using the formula: 1000 m / body weight (in grams), where m – the mass of the spleen; spleen weight-to-body height ratio (KI) by using the formula: spleen weight (g) / height (cm); spleen weight-to-body surface area ratio (Ks) by using the formula: spleen weight (g) / body surface area (m²). Statistical analysis was performed by using Statistica 10.0 software package. Febrile state in most cases is not accompanied by changes in spleen size. However, decreased spleen size was found in one (4.5%) patient aged 58 years, whereas splenomegaly – in 2 (9%) cases (SWC range 5.5- 5.9) in young patients aged 18 and 25 years. The course of infectious mononucleosis in 25% cases was not accompanied by change in spleen size. In other cases, both decreased (20.8%) and increased (54.2%) spleen size were observed. In particular, decreased spleen size was detected in patients with average age of 43.6±14.5 years, whereas increased spleen size (SWC range 4-8.9) was typical for young people aged 25±8 years. Febrile state in most cases is not paralleled altered spleen size. Infectious mononucleosis was associated with the three types of altered spleen size: no change, decreased spleen size characteristic to older patients, or increased spleen size observed in young subjects. Ultrasound examination of the spleen with measuring its morphometric parameters represent objective criteria allowing to fully assess the state of this immune organ and reveal degree of its involvement in the pathological process at the preclinical level.