Ultrasound diagnosis of splenic lymphoma: ROC analysis of multidimensional splenic indices.

To assess the efficacy of splenic size in the sonographic diagnosis of lymphomatous involvement of the spleen, the authors studied 31 patients with splenic lymphoma (Hodgkin's disease, 17 and non-Hodgkin's lymphoma, 14) and 218 individuals without evidence of splenic disease. All subjects were studied with both a linear and a sector transducer. The longitudinal, transverse and diagonal diameters of the spleen were measured, and two- and three-dimensional splenic indices were calculated. The analysis of the diagnostic performance of these criteria, compared by means of receiver-operating characteristic (ROC) curves, revealed that diagnosis of splenic involvement by malignant lymphoma was considerably more reliable with a sector than with a linear scanner. If the longitudinal diameter was measured with a sector scanner, sensitivities were 66% and 74%, at specificities of 95% and 90% respectively (cut-off points: 12.5 cm and 11.3 cm, respectively). For the sector scanner, there was no advantage in using other diameters or multidimensional indices. Additional ROC analysis of recently published data indicating excellent discrimination capacity of a computed tomography index revealed that these results were largely owing to patient selection. In contrast, our data suggest that the potential of current non-invasive assessment of splenic lymphoma is limited. However, ultrasound may eventually help to eliminate staging laparotomy in selected cases, e.g. in patients with low risk of abdominal disease and with increased surgical risk.