Kikuchi-Fujimoto disease is a rare, self-limited, histiocytic, necrotizing lymphadenitis first described in Japan in 1972. Necrosis of lymph node tissue is caused by apoptosis and may be virally induced. It commonly presents with cervical lymphadenitis and fever. Despite its low incidence, Kikuchi-Fujimoto disease should be considered in patients with persistent lymphadenopathy. Originally thought to occur only in young Asian women, it is now recognized in other geographic regions. We report a 30-year-old white woman with Kikuchi-Fujimoto disease. We discuss the clinical features, differential diagnosis, radiography, pathology, and outcome.
Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is an uncommon, self-limited, benign, systemic lymphadenitis of unknown etiology. By the late 1960s, members of the Pathology Reference Center [
A 30-year-old white woman presented to the emergency department with a 4-day history of a left anterior cervical mass. She reported that swelling in her upper neck had been waxing and waning. In the 36 hours before her presentation, the swelling had decreased the range of motion in her neck. The mass was causing severe pain and tenderness over the sternocleidomastoid muscle, and she also had mild trismus. She reported intermittent fevers up to
On physical examination, the patient was febrile, and there was obvious left cervical lymphadenopathy with warmth and tenderness over the neck. Nasal and oral examination results were unremarkable. Her white blood cell count was
Axial contrast-enhanced CT. A 2 cm well-circumscribed, low attenuation mass (arrow) is present at the expected location (jugulodigastric (Level 2) lymph node or second branchial cleft cyst).
The infectious disease consulting service recommended an ultrasonographically guided needle aspiration of the presumptive cystic fluid. When ultrasonography indicated the mass was solid (Figure
Ultrasonogram of the largest lymph node at the site of cervical swelling. The lymph node was a solid mass measuring
Ten days after the biopsy, the patient reported ear and neck pain but denied any recurrent fevers. She was advised to take ibuprofen for 2 to 3 days and to return for reimaging if the pain persisted. The patient’s pain eventually resolved, and she had no further complications.
The incidence of KFD is unknown. It has been observed in patients aged 19 months to 75 years (typically 25–29 years old) [
The etiology of KFD has not been identified. Necrosis of the lymph nodes appears to be caused by apoptosis [
Despite the low incidence, KFD should be considered in patients with persistent lymphadenopathy, and an early diagnosis from biopsy findings can prevent unnecessary investigations and treatments. Most patients (80%) present with cervical lymphadenitis, although any lymph node region may be involved [
Radiographic findings specific to KFD have not been established, and reports of KFD in the medical literature have largely focused on the disease pathology. Chest radiography should be included in the diagnostic evaluation to eliminate the possibility of malignancy or tuberculosis. CT and ultrasonography are common and often helpful before obtaining a biopsy specimen. Ultrasonography frequently shows lymph nodes with a hypoechoic center and a hyperechoic rim [
The radiographic diagnosis of KFD is broad and includes Hodgkin and non-Hodgkin disease, metastatic tumor, tuberculosis, nontuberculous mycobacterial infection, SLE, human immunodeficiency virus infection, infectious mononucleosis, cat-scratch disease, mucocutaneous lymph node syndrome (Kawasaki disease), and toxoplasmosis. In 1 series, 29% of patients with KFD were initially misdiagnosed as having Hodgkin or non-Hodgkin disease [
There are no specific assays available to confirm the diagnosis of KFD, but laboratory tests are used to eliminate other causes of cervical lymphadenopathy. Peripheral blood tests indicate 25.0% to 58.3% of KFD patients had leukopenia, and 25.0% to 31.1% of patients had atypical lymphocytes [
Patients suspected of having KFD often undergo fine-needle aspiration before an excisional biopsy is performed. Aspiration was not performed on our patient because ultrasonography indicated that the mass was solid.
The definitive diagnosis of KFD is made through lymph node excision biopsy and histologic examination. There are several classic histologic features of KFD. The affected lymph nodes have patchy necrotizing regions (the degree of necrosis varies widely among patients), mainly in the paracortical areas (Figure
Distribution of necrotic foci (mottled tissue) and mononuclear cells in the paracortical region of a lymph node (Hematoxylin-eosin stain, original magnification
Necrotizing lymphadenitis of a lymph node with associated perinodal necrosis. Some mononuclear cells may represent macrophages phagocytosing nuclear debris (Hematoxylin-eosin stain, original magnification
The differential diagnosis of a slow-growing neck mass is extensive and includes malignant lymphoma, systemic lupus erythematosus (SLE), Hodgkin disease, toxoplasmosis, metastatic carcinoma, infectious mononucleosis, acquired immunodeficiency syndrome, cat-scratch disease, and angioimmunoblastic lymphadenopathy [
In 80% of patients, KFD is self-limited and resolves within 1 to 6 months without specific treatment [
KFD is a self-limited and typically benign lymphadenitis of unknown etiology now recognized in multiple geographic regions and races. The clinical suspicions of the otolaryngologic surgeon, in conjunction with the pathology findings, are critical for an accurate diagnosis. Understanding the characteristic clinical presentation and histologic findings of KFD help exclude malignant disorders and nonneoplastic conditions that require specific therapy.
Computed tomographic, computed tomography
Kikuchi-Fujimoto disease
Systemic lupus erythematosus