CASE REPORT: Reactive lymphoid hyperplasia of liver coexisting with chronic thyroiditis: Radiographical characteristics of the disorder

Background: Reactive lymphoid hyperplasia of the liver is an extremely rare entity, with six cases reported so far. Methods:We encountered a 47-year-old Japanese female with reactive lymphoid hyperplasia of the liver, which coexisted with chronic thyroiditis. The le sion was discovered incidentally as a hypo-echoic mass with a hyper-echoic rim at a routine ultrasonography examination. It increased from 12 to 17 mm diameter in 6 months. Radiological studies, such as contrast-enhanced comp uterized tomography (CT) and angiography demonstrated a hypervascular lesio n. Results: It was consequently diagnosed as a neoplasm with malignant potenti ality and she underwent partial hepatectomy. The lesion was composed of sma ll mature lymphocytes which formed prominent lymphoid follicles with germin al centres, scattered plasma cells and stromal fibrosis. Immunohistochemica l study revealed polyclonal origins of the involved lymphocytes. DNA analys is for the immunoglobulin heavy gene and the T cell receptor beta gene usin g Southern blot hybridization showed no monoclonality. The following featur es have characterized the images in past cases, as well as ours: hypo-echoi c mass, occasionally with a rim, in ultrasonography and hypervascularity, s hown by angiography and enhanced CT.