KIKUCHI FUJIMOTO DISEASE PRESENTING AS PYREXIA OF UNKNOWN ORIGIN. A CASE REPORT WITH REVIEW OF LTERATURE AND THE ROLE OF IMMUNOHISTOCHEMISTRY IN DIAGNOSIS
Kikuchi Fujimoto Disease or Histiocytic Necrotising Lymphadenitis [ KFD/HNL ] is a rare differential diagnosis of chronic cervical lymphadenopathy of unknown etiology with a worldwide distribution and a higher prevalence in Asians with a predilection for young women. It is a benign self limited disease with an etiological hypothesis of viral, bacterial or autoimmune causation although no definite cause has been established though silicon breast implants have also been incriminated as the culprit. The diagnosis of KFD should be considered in all cases of lymphadenopathy of undetermined origin particulary in the setting of Asian patients where it has been misdiagnosed from Lymph Node Tuberculosis to Lymphoma. Diagnosis is made by excision of the lymph node followed by histopathological examination & immunohistochemistry. Histological findings include paracortical areas of coagulative necrosis with abundant karyorrhectic debris. There is an abundance of T cells with predominance of CD8+ over CD4+ T cells. Differential diagnosis includes lymphoma, lymphadenitis associated with SLE, TB, Sarcoidosis or even Adenocarcinoma. Accurate clinicopathological recognition is crucial for a definitive diagnosis. We report a case of fever with cervical lymphadenopathy in a 24 year old young female who after thorough evaluation was proved to have KFD.
KEYWORDS: Kikuchi Fujimoto Disease , Histiocytic Necrotising Lymphadenitis , Karyorrhectic debris, Coagulative necrosis, Immunohistochemistry.