AJR:194, January 2010
Takuya Ueda, Christe Andreas, Jun Itami, Kunihisa Miyakawa, Hajime Fujimoto, Hisao Ito, Justus E. Roos
OBJECTIVE. The purpose of this study was to evaluate the radiologic features of pyotho-rax-associated lymphoma on CT scans and chest radiographs.
MATERIALS AND METHODS. Radiographs and CT scans of 21 patients with bi-opsy-proven pyothorax-associated lymphoma (17 men, four women; median age, 71 years; range 52-77 years) were retrospectively identified. Two readers in consensus analyzed the morphologic imaging features of pyothorax-associated lymphoma and determined their re-lation to the preexisting chronic empyema cavity. In 13 cases, gallium scans were available and were reviewed.
RESULTS. Sixteen patients had a history of artificial pneumothorax therapy for tubercu-losis. Pyothorax-associated lymphoma was visualized mainly (71.4% of cases) as extrapul-monary pleural masses on chest radiographs. The CT features included a lenticular (60%) or crescentic (20%) soft-tissue mass located eccentrically at the margin of a coexistent empy-ema cavity, which was present in all cases. Masses of pyothorax-associated lymphoma were commonly located in the lateral costal pleura (50%) or at the costophrenic angle (30%). The tumor matrix often appeared heterogeneous and contained areas of necrosis (60%). Direct in-vasion of the chest wall, ribs, lung parenchyma, and abdomen was found in 75%, 50%, 25%, and 25% of patients. Gallium scans, when available, showed marked uptake in 10 of 13 pa-tients (76.9%).
CONCLUSION. In patients who have undergone artificial pneumothorax therapy for tu-berculosis more than 20 years in the past, a pleural soft-tissue mass adjacent to the margin of a coexistent empyema cavity suggests the presence of pyothorax-associated lymphoma. Knowl-edge of the typical radiologic findings and locations of pyothorax-associated lymphoma help in the diagnosis of this rare pathologic entity.