Clinicopathological study of non-granulomatous necrotizing lymphadenopathies

Abstract

Non-granulomatous necrotizing lymphadenopathy (NGNL) is not a specific entity. It is seen in various conditions like Kikuchi-Fujimoto disease (KFD), Systemic Lupus Erythematosus (SLE), tuberculosis, lymphoma/metastasis and lymph node infarction. These conditions mimic each other histologically but it is necessary to identify the correct pathology as the treatment differs significantly. To highlight the subtle morphological features which lead to the etiological diagnosis in NGNL. The lymphnode biopsies (N=198), reported in our institute as NGNL, over 4½ year study period, were retrieved. Of these, the benign cases were 64 in total, with 40 cases of KFD and 8 cases of SLE. H&E, special stains and immunohistochemistry slides were reviewed by two pathologists. Histomorphological features like amount of necrosis, apoptotic debris, vasculitis, presence of neutrophils, eosinophils, histiocytes, plasma cells, hematoxylin bodies, Azzopardi phenomenon and thrombus formation were studied. Logistic regression analysis was performed to identify the most significant histopathological parameter with each disease. Kendall’s Tau matrix plot analysis was used to measure the correlation between the disease and the histopathologic variables. Features like vasculitis, hematoxylin bodies and Azzopardi phenomenon showed strong correlation with SLE and inverse correlation with KFD. Apoptotic debris, paucity of neutrophils and eosinophils had a strong positive association with KFD. The histological features help in differentiating the various entities associated with NGNL. It is necessary to correlate with clinical details and various laboratory parameters to reach a conclusive diagnosis because these conditions have varied treatment modalities.