Kikuchi Fujimoto disease (KFD) in a 31-year-old woman.

Kikuchi Fujimoto disease (KFD), or Kikuchi histiocytic necrotizing lymphadenopathy is an extremely rare disease known to have a worldwide distribution with a higher prevalence among Japanese and Asians.1 There is much speculation about the cause of KFD; a viral or autoimmune cause has been suggested.1 KFD is a benign, self-limited disease that resolves in 1 to 4 months.4 An early biopsy can be instrumental in preventing unnecessary investigations and potentially harmful treatments.5 We report a case of a woman who presented with this rare condition. A 31-year-old Caucasian woman presented to the hospital with progressively worsening, painful right cervical and right axillary lymphadenopathy of 10 days duration. She denied fever, chills or malaise. She had similar episodes of recurrent painful lymphadenopathy in the past. During these episodes she was treated with empiric antibiotics, followed by partial resolution of the symptoms. Her other medical history was significant for asthma and chronic bronchitis. She denied any sick contacts or recent travel. She did not have any pets at home and denied any recent contact with cats or insects. She did not have high-risk behaviors for HIV. Physical examination revealed enlarged, tender lymph nodes in the right posterior cervical, axillary and supraclavicular regions. A complete blood count showed an absence of leukocytosis and a mild predominance of lymphocytes. A CT scan of the neck confirmed multiple enlarged lymph nodes in the right posterior neck, carotid sheath, submandibular and supraclavicular regions. A CT scan of the chest revealed lymphadenopathy in the anterior mediastinum, left para-tracheal, pre-tracheal and bilateral axillary regions, while the abdomen and pelvis were unremarkable. HIV RNA, Bartonella antibodies, EBV, immunoglobulin panel, CMV, RPR, and ANA were negative. Biopsy of the right cervical lymph node revealed crescentic histiocytes admixed with nuclear debris and apoptotic cells (Figures A, B, C), consistent with Kikuchi lymphadenopathy. Immunostaining of lymphoid cells was positive for CD3, CD4 and CD8 T cells. She was treated symptomatically with pain relief and hydration and was discharged after her symptoms had improved. The diagnosis can only be made by histological examination of the node, which may show the following changes typical for KFD: paracortical necrotic foci, surrounded by histiocytic aggregates, irregular rounded eosinophilic areas of different sizes in the paracortex and cortex with the presence of numerous histiocytes, lymphocytes, immunoblasts, plasmacytoid monocytes and eosinophilic granulated cellular debris.2 It is typical not to find epithelioid cells and neutrophil granulocytes in the necrotic centers. In particular, the disease needs to be distinguished from highgrade lymphoma and SLE lymphadenitis.2 Figure A. Biopsy of the cervical lymph node showing histiocytes admixed with nuclear debris and apoptotic cells.