Extranodal Hodgkin disease: Spectrum of disease

Extranodal lesions in Hodgkin disease may develop and spread to virtually a ny organ system, simulating other neoplastic or infectious diseases. It is important to determine whether extranodal involvement represents a primary manifestation or dissemination of systemic disease, which has a poorer prog nosis. Computed tomography (CT) is the preferred modality, although ultraso nography and magnetic resonance (MR) imaging may also be helpful. CT is sup erior to conventional radiography in assessing chest disease, although MR i maging is more sensitive than CT in detecting chest wall involvement. CT is preferred for evaluating hepatic lymphoma and has proved particularly valu able in diagnosing gastric. lymphoma and detecting renal or perirenal masse s. CT and MR imaging are equally effective in detecting brain Hodgkin disea se; however, the latter is superior in the detection of extracerebral tumor deposits in the subdural or epidural space. MR imaging is also preferred f or evaluating meningeal and spinal cord involvement. Both MR imaging and CT allow excellent assessment of bone texture and accurate analysis of tumora l bone invasion, but MR imaging is superior in demonstrating bone marrow in filtration, and CT is superior in delineating the extent of cortical bone d estruction. In the future, metabolic positron emission tomography may provi de more information about extranodal lymphoma than do the current imaging m odalities.