Ultrasonographic findings and differentiation of benign and malignant focal splenic lesions

The purpose of this study was to analyse the sonographic findings of focal splenic lesions with an attempt to differentiate benign lesions from malignancies. The sonographic findings of 53 cases of verified focal splenic lesions, excluding post-traumatic haematomas and phleboliths, were restrospectively analysed. Of the 53 cases, 30 cases (57%) were benign and 23 cases (43%) were malignant. The malignancies included lymphoma (n=13), metastases (n=10); while the benign lesions included cysts (n=17), infarcts (n=3), and abscesses (n=5), and one case each of haemangioma, hamartoma, spontaneous rupture, tuberculosis, and lymphangioma. Significant differences were noted between the benign and malignant groups with respect to the presence of solitary lesions (p<0.0001), anechoic mass (p<0.0001), lesions with highly echogenic foci due to gas or calcification (p = 0.0303), hyperechoic/mixed echoic lesions (p<0.0001), presence of extrasplenic abdominal masses (p<0.0001), and nodules with the target sign (p<0.0001). Solitary lesions, anechoic mass, and lesions with highly echogenic foci due to gas or calcification each had a positive predictive value of 85%, 100%, and 100%, respectively, for the lesions to be benign. The multifocal/diffuse lesions, presence of extrasplenic abdominal masses, hyperechoic/mixed echoic lesions, and nodules with the target sign each had a positive predictive value of 70%, 100%, 70%, and 100%, respectively, for the lesions to be malignant. In summary, focal lesions with anechoic pattern or echogenic foci due to gas or calcification are suggestive signs of benign process. The sonographic observations of multifocal or diffuse solid lesions, especially those associated with target sign or extrasplenic abdominal masses are suggestive of malignancy.