Kikuchi-Fujimoto and Kimura diseases: the selected, rare causes of neck lymphadenopathy.

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a benign and self-limiting disease typically characterized by the enlargement of regional lymph nodes and accompanied by fever. KFD affects predominantly young adult females of Asian origin and is rarely seen in European countries, where it may cause diagnostic difficulties. Kimura disease is a rare and benign chronic inflammatory soft tissue disorder of unknown origin, characterized by a triad of painless subcutaneous masses in the head or neck region accompanied by regional lymphadenopathy, blood and tissue eosinophilia, and markedly elevated serum immunoglobulin E levels. Although most cases of Kimura disease have originated in China, Japan or Southeast Asia, there have been sporadic case reports from Europe and America. Herein, we review in detail the clinical presentations, complications and current concepts in the pathogenesis, diagnosis and treatment of these diseases.