Clinical diagnosis
Case 161
【Progress】
She received fine needle biopsy of the swollen neck lymph-node. It revealed no existence of malignant cells. Her medicine was changed from Loxonin to Voltaren. Thereafter, she was given predonin (20mg/day) for a week.
【Discussion】
Subacute necrotizing lymphadenitis is found by Kikuchi M and Fujimoto Y independently in 1972 (1, 2), and then, this disease is called Kikuchi disease or Kikuchi Fujimoto disease. The pathogenesis is still controversial. However, it is believed that this disease might be T cell mediated immune response (delayed allergic disease). Microscopic examination of the lymph node shows the proliferation of the blast lymphocytes and histiocytes without any infiltration of neutrocytes and eosinophils (1-4). Especially, CD8 positive T cell proliferation related to apoptosis is found in the lymph nodes (3, 4). When T cell is activated by non-specific antigen such as chemical or viral stimulation, the protein called Fas legand manifests at the surface of activated T cell which induces apoptosis (3, 4). As the activated T cells survives longer, the sensitivity of Fas legand elevates, leading to susceptibility to apoptosis. It implies that this apoptotic system inhibits the excessive immune response and eliminate the activated T cells to attack the self. Macrophages and histiocytes play a role to phagocyte the infected T cells or apoptotic T cells. Then, in the swollen lymph node of subacute necrotizing lymph adenitis, there exists infected T cells, activated T cells, killer T cells and histiocytes. In our case, fine needle biopsy showed marked proliferation of mature lymphocytes.
The clinical characteristics of subacute necrotizing lymphadenitis are as follows; it affects a young lady (mostly twenties) (3 -5) ; it causes fever and hemi-lateral lymphadenopathy (possible swollen bilateral lymph nodes) and sometimes skin rashes; antibiotics resistant; no elevation or decrease of leukocytes number in the peripheral blood. Electronic microscopy shows the tubule-reticular structure in the lymphocytes of this disease, which are similar to that in the lymphocytes seen in systemic lupus erythematosus (SLE). Further, the case of SLE occurrence is reported to occur following subacute necrotizing lymphadenitis. Kikuchi disease is believed to be a SLE-like autoimmune condition caused by virus-infected transformed lymphocytes. In our case, persistent fever, painful antibiotics-resistant lymphadenitis were found in a twenty one-year-old lady with leukocytes count of 5420/㎣.
The radiologic characteristic of subacute necrotizing lymphadenitis are as follows (6 – 8): necrotic swollen lymph nodes; swollen hemi-lateral lymph nodes (possible bilateral): posterior cervical lymph nodes. No necrotic focus is found in the early phase. It mimics bacterial or viral lymphadenopathy or malignant lymphoma. Necrotic lymphadenopathy mimics Tbc lymphadenopathy. Then, it is crucial to check the clinical and laboratory findings in addition to the radiologic findings in the diagnosis of subacute necrotizing lymphadenitis. In our case, enhanced CT using contrast medium showed swollen hemi-lateral necrotic lymphadenopathies.
【Summary】
We present a twenty one-year-old female suffering from left neck pain and continuous antibiotics-resistant fever of around 38℃ for two weeks. Clinical findings laboratory test revealed hemi-lateral swollen lymph nodes and no elevation of leukocytes count, respectively. Enhanced CT using contrast medium showed swollen necrotic lymph nodes at the deep neck and posterior neck, leading to the diagnosis of subacute necrotizing lymphadenitis. It is borne in mind that subacute necrotizing lymphadenitis is found by Kikuchi M and Fujimoto Y independently. Microscopically, infected T cells, activated T cells, killer T cells and histiocytes are found in the necrotic lymph nodes. It is believed that subacute necrotizing lymphadenitis is a T cell mediated immune condition, SLE-like autoimmune condition caused by virus-infected transformed lymphocytes.
The clinical and radiologic characteristics of subacute necrotizing lymphadenitis are as follows; a young lady (mostly twenties) ; fever and hemi-lateral painful lymphadenopathy (possible swollen bilateral lymph nodes) and sometimes skin rashes; no elevation or decrease of leukocytes; necrotic swollen lymph nodes; swollen hemi-lateral lymph nodes (possible bilateral): posterior cervical lymph nodes. It is necessary to differentiate this disease from bacterial or viral lymphadenopathy, malignant lymphoma or Tbc lymphadenopathy.
【References】
1.Kikuchi M. Lymphadenitis showing focal reticulum cell hyperplasia with nuclear debris and phagocytes: a clinicopathological study. Acta Hematol Jpn. 1972;35:379–380.
2.Fujimoto Y. Cervical subacute necrotizing lymphadenitis: a new clinicopathologic entity. Naika. 1972;20:920–927.
3.Dorfman RF. Histiocytic necrotizing lymphadenitis of Kikuchi and Fujimoto. Arch Pathol Lab Med. 1987;111:1026–1029.
4.Rammohan A, et al. Kikuchi-Fujimoto Disease: A Sheep in Wolf's Clothing. J Otolaryngol Head Neck Surg. 2012; 41 (3): 222–26.
5.Martínez-vázquez C, et-al. Histiocytic necrotizing lymphadenitis, Kikuchi-Fujimoto's disease, associated with systemic lupus erythemotosus. QJM. 1997;90 (8): 531-3.
6.Kwon SY, et-al. CT findings in Kikuchi disease: analysis of 96 cases. AJNR Am J Neuroradiol. 2004;25 (6): 1099-102.
7.Haaga JR, et al. CT and MRI of the whole body. Mosby. (2009) ISBN:0323053750.
8.Lee S, et al. Kikuchi Disease: Differentiation from Tuberculous Lymphadenitis Based on Patterns of Nodal Necrosis on CT. American Journal of Neuroradiology January 2012, 33 (1) 135-140.
2019.9.11