Kikuchi-Fujimoto disease in the regional lymph nodes with node metastasis in a patient with tongue cancer: A case report and literature review

Abstract

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare self-limiting disorder typically affecting the cervical lymph nodes (LNs), which is often misdiagnosed as other LN-associated diseases. KFD frequently presents with necrotic lesions and recurrences, which are also features of metastatic LNs. Clinicians may thus suspect LN metastasis when they encounter ipsilateral cervical lymphadenopathy in a patient with head and neck cancer. The present study reports the case of a 48-year-old man with tongue cancer and KFD affecting the right edge of his tongue and ipsilateral cervical LNs. LN metastasis was initially suspected, but pathological examination of the dissected LNs revealed one necrotic metastatic lesion and two necrotic KFD lesions. Ipsilateral cervical lymphadenopathy recurred 6 years after the initial surgery, and it was not possible to differentiate clinically between a second primary tumor and recurrent KFD prior to treatment. To the best of our knowledge, this is the first reported case of simultaneous tongue cancer, regional LN metastasis and KFD. This highlights the requirement to consider KFD in the event of LNs with necrotic lesions but no cancerous cells. A combination of clinical and pathological approaches may aid in the diagnosis of KFD, in addition to ruling out LN metastasis in initial and recurrent lymphadenopathies. The present study indicate that a diagnosis of KFD should be considered in patients with head and neck cancer that exhibit necrotic LNs lacking cancerous cells. This is important, as misdiagnosis of KFD as LN metastasis may lead to unnecessary adjuvant therapy.

Keywords: Kikuchi-Fujimoto disease; cancer; clinical; lymph node metastasis; necrosis; pathology; recurrence; tongue.

Figure 1.

Intraoral image of the lesion captured at the initial visit. Physical examination revealed a hard elastic 2.0×1.5 cm mass on the right side of the tongue.

Figure 2.

Computed tomography revealed a 1.2×0.9 cm mass with rim enhancement and a central necrotic lesion in the level I lymph node (indicated by the arrow). This was identified histologically as lymph node metastasis. Lymph node lesions <1.0 cm in diameter in levels II and III with homogeneous contrast enhancement (indicated by the arrowhead) were diagnosed histologically as Kikuchi-Fujimoto disease. All of above lymph nodes were in the right neck region.

Figure 3.

Histopathological examination revealed squamous cell carcinoma with one metastatic lymph node at level I, with necrotic lesions. Magnification, ×40.

Figure 4.

Histopathological examination revealed a Kikuchi-Fujimoto disease lymph node at level II with karyorrhectic foci and large numbers of histiocytes. Magnification, ×400.

Figure 5.

Histiocytes in the karyorrhectic foci of the Kikuchi-Fujimoto disease lesion were positive for cluster of differentiation 68. Magnification, ×200.

Figure 6.

FDG-positron emission tomography revealed FDG uptake in the right posterior cervical region. FDG, 2-[18F]-fluoro-2-deoxy-D-glucose.

Figure 7.

Histological findings following lymph node excision suggested Kikuchi-Fujimoto disease. Magnification, ×200.