Imaging features of primary lymphoma of bone

OBJECTIVE. Our objective was to describe the imaging appearances of primary lymphoma of bone, including conventional radiographic, scintigraphic, CT, and MR imaging features. MATERIALS AND METHODS. We retrospectively reviewed 237 pathologically prove n cases of primary lymphoma of bone. Evaluation included patient age, sex, lesion location, and pattern of bone destruction. Pathologic type, perioste al reaction, sequestrum, soft-tissue mass, extension across joints, and pat hologic fracture were also noted. RESULTS. The study population included 151 males and 86 females (ratio 1.8: 1; range, 2-88 years; mean age, 42 years). Common locations were the distal femoral diametaphysis; proximal metadiaphysis of the tibia, femur, and hum erus; and femoral mid shaft. Long bones were involved more often than flat bones (71% versus 22%). Common appearances were a lytic (70%) or mixed-dens ity (28%) lesion with most cases showing a permeative or motheaten pattern (74%). Periosteal reaction was seen in 58% of the long bones. Sequestra wer e found in 37 patients (16%). Soft-tissue masses were present in 113 patien ts (48%). Extension across joints was seen in nine patients (4%). Pathologi c fractures occurred in 53 patients (22%). Radionuclide (n = 56), CT (n = 4 5), and MR (n = 20) features were usually nonspecific. Pathologic types inc luded non-Hodgkin's (n = 223) and Hodgkin's (n = 14) lymphoma. CONCLUSION. Primary lymphoma of bone most often involves the diametaphysis of a major long bone and has an aggressive pattern of lytic bone destructio n and associated soft-tissue mass. CT and MR imaging can suggest the diagno sis, particularly when a large soft-tissue mass and abnormal marrow attenua tion or signal intensity is seen without extensive cortical destruction.