The case is described of a Kikuchi-Fujimoto disease, in a 22-year-old female, onset of which was characterised by rapidly evolving lateral neck lymphadenopathy. Since clinico-radiological findings suggested a lymphoproliferative disease, it was mandatory, in order to establish the diagnosis and programme a suitable treatment protocol, to collect a lymph node biopsy specimen. The histological pattern was characteristic of Kikuchi-Fujimoto disease necrotizing lymphadenitis. Bearing in mind the difficulties encountered in the diagnosis of Kikuchi-Fujimoto disease, due not only to lack of a characteristic clinical pattern but also to the generic and aspecific findings emerging from radiological evaluation, the Authors stress the important role of histological examination in establishing the nature of the disease. In their opinion, onset of a rapidly evolving lateral neck lymphadenopathy, in a young patient, in the absence of well-defined disorders possibly responsible for the condition, and in order to establish a correct diagnostic approach, should induce the ENT specialist to take into consideration the possible presence of Kikuchi-Fujimoto disease, even if this is to be considered a rare finding.