Lymph node pathology in patients with a clinical diagnosis of angioimmunoblastic lymphadenopathy with dysproteinemia (AILD): an analysis of 37 cases.

Lymph node pathology was analyzed in 37 patients clinically diagnosed as having angioimmunoblastic lymphadenopathy with dysproteinemia (AILD). Results confirmed AILD in 11 cases and were compatible with AILD in 2 cases. Reactive lymphoid hyperplasia was found in 15 cases, 2 cases had angiofollicular lymphoid hyperplasia or Castleman's disease, atypical lymphoid hyperplasia suggestive of malignant lymphoma was observed in 3 cases, and malignant lymphoma was diagnosed in the remaining 4 cases. The histopathologic features of AILD which differed from reactive lymphoid hyperplasia were effacement of lymph node architecture, vascular arborization, high endothelial venules, and capsular infiltration (p-value < 0.05). Lymphodepletion and PAS-positive interstitial material were occasionally found in both groups (p-value > 0.05). Among the 15 cases with pathology of reactive lymphoid hyperplasia, we identified 8 cases with hyperplastic lymphoid follicles, interfollicular plasmacytosis and hypervascularity which we designated as a hyperimmune reaction. This study emphasizes the necessity of lymph node examination in all patients with a clinical suspicion of AILD.