Lymph node lesion in adult-onset Still's disease resembling peripheral T-cell lymphoma: a report of three cases.

Adult-onset Still's disease (AOSD) is known to be a cause of fever of unknown origin. We describe the clinicopathologic, immunohistologic, and genotypic features of 3 patients with lymph node lesions from AOSD, which posed a serious diagnostic difficulty from peripheral T-cell lymphomas. The patients were 22-, 26-, and 63-year-old Japanese women. At the onset of disease, all patients had multicentric lymphadenopathy in association with clinical and laboratory findings suggestive of a malignant lymphoma. None of the patients developed malignant lymphomas during the follow-up period. Histologically, the lesions were characterized by paracortical hyperplasia with prominent vascular proliferation. In the paracortical area, there was a mixed infiltrate including small-to-medium-sized lymphocytes, variable numbers of eosinophils, plasma cells, and B immunoblasts. Polymerase chain reaction analysis demonstrated that neither clonal rearrangement of the T-cell receptor gamma-chain gene nor immunoglobulin heavy-chain rearrangement was detected in any patient. Although AOSD appears to be a rare systemic inflammatory disorder, the lymph node lesion should be added to the differential consideration of benign lymph node lesions simulating node-based peripheral T-cell lymphoma.