Contrast-Enhanced Sonography in Patients with Hyposplenia: A Retrospective Analysis in Forty-Three Patients

Purpose: In contrast to splenomegaly, the clinical value of a small spleen (hyposplenia) is unclear. Contrast-enhanced ultrasound (CEUS) has not been investigated systematically in hyposplenia. Methods: Between February 2005 and January 2017, 43 patients with hyposplenia (< 7 × 3 cm) were examined by B-mode ultrasound (US) and CEUS. A retrospective data analysis was performed. Results: A total of 39 (91%) patients had an underlying disease (UD; allogenic stem cell transplantation, n = 16; autoimmune-diseases, n = 7; sickle cell anemia, n = 5; solid tumors, n = 5; others, n = 6). In 4 (9%) cases, hyposplenia was an incidental finding. The echogenicity of the spleen was normal (homogeneous, isoechogenic) in 17 (39.5%) and abnormal in 26 (60.5%) cases (inhomogeneous, n = 26 and hyperechoic, n = 9). In CEUS, 21 (49%) patients presented a normal isoenhancement. An abnormal enhancement was detected in 22 (51%) patients with UD (arterial/parenchymal inhomogeneous, n = 1; no [arterial, n = 3 and parenchymal, n = 6]; reduced [arterial, n = 8 and parenchymal, n = 15]). Conclusions: Hyposplenia is a rare pathologic finding and often associated with hematological/oncological and autoimmune diseases. Furthermore, altered B-mode US appearance and a pathological CEUS pattern are frequently found. However, the clinical implication, especially regarding splenic function remains obscure to date.