Development of Kikuchi-Fujimoto disease after a cervical lymph node metastasis of mucoepidermoid carcinoma: a case report.

Kikuchi-Fujimoto disease (KFD) was first reported by Kikuchi and Fujimoto in 1972 as a rare disease with lymphadenitis of unknown etiology. KFD is characterized by the main symptoms of fever and enlarged cervical lymph nodes (LNs), which are similar to the features of other LN-associated diseases. Therefore, it is difficult to diagnose this condition. We report the case of a 24-year-old woman who presented with KFD after surgery to treat a mucoepidermoid carcinoma of the palate and dissection of the left neck. The patient presented with a fever and right cervical lymphadenopathy when she visited our department for a regular follow-up related to the mucoepidermoid carcinoma. The results of computed tomography and ultrasonography evaluations led to a clinical diagnosis of lymph node metastasis, and a right neck dissection was performed. However, the pathological tissue analysis did not suggest malignancy but showed necrosis and various cellular infiltrates. We made a diagnosis of KFD from these clinical and pathological features. KFD may be misdiagnosed as a LN-associated disease such as metastasis. Clinically, KFD should be considered in patients with head and neck cancer who present with cervical lymphadenopathy.