Histopathological study of lymph node lesions in the acute phase of Kawasaki disease

Aims: To review the histopathological features of cervical LNs, and to clarify the changes in extracervical LNs, in acute Kawasaki disease (KD). Methods and results: The samples were obtained from 33 patients with acute-phase KD. We divided the LNs into those in the neck (n = 23) and those located elsewhere (n = 26), and investigated them histologically. Changes occur not only in the cervical region, but also in LNs throughout the body. Most lymphadenopathy is non-specific, caused by sinus expansion and paracortical zone enlargement, but there are also necrotic lesions of various sizes that can be surmised to result from ischaemic changes in some LNs. Necrotic foci start to develop immediately below the capsule, and are accompanied by fibrin thrombi in the small vessels and perivascular nuclear debris. Especially in the case of cervical LNs with necrosis, a high degree of non-purulent inflammation develops in the LN capsule and surrounding connective tissue. Conclusions: In addition to lymphadenopathy with necrosis, KD should be suspected if there is non-purulent inflammation of the LN capsule and/or surrounding connective tissue featuring mainly monocytes/macrophages.