Juvenile temporal arteritis.

Juvenile temporal arteritis (JTA) is a nongranulomatous inflammation of the temporal artery with fragmentation of the internal elastic lamina and no concurrent systemic manifestations. It is a rare clinicopathologic entity with fewer than 20 reported cases, most of which represent localized disease with no recurrence or systemic symptoms at follow-up of up to 2 years. Histopathologic features can include lymphoeosinophilic infiltrate and endothelial proliferation. As the histology may resemble angiolymphoid hyperplasia with eosinophilia or Kimura disease, whether JTA is a discrete localized disease or a manifestation of these systemic conditions has been debated. We present a case of a 36-year-old Jamaican woman with a painful forehead nodule that showed histologic features of JTA, including intimal hyperplasia, lymphoeosinophilic inflammation of the vessel wall, and disruption of the internal elastic lamina; distinctive signet ringlike cytomorphologic alterations of the endothelial cells were noted as well. The lesion also showed extensive subcutaneous lymphoeosinophilic infiltrates and neovascularization with extension into the underlying muscle consistent with angiolymphoid hyperplasia with eosinophilia or Kimura disease. As the connection between JTA and angiolymphoid hyperplasia with eosinophilia and Kimura disease is currently debated and most reported cases of JTA have had only brief follow-up, the long-term sequelae of JTA are not known and careful patient monitoring may be necessary.