Kikuchi disease associated with Still disease

A 32‐year‐old white man with no previous medical past was admitted to our department with an 8‐month intermittent history of acute spiking fever with axillary, inguinal, and neck lymphadenopathy, arthritis, and cutaneous eruption. Cutaneous examination showed nonpruriginous, indurated erythematous papules affecting the face, ears, and trunk, suggestive of subacute lupus erythematosus ( Fig. 1a,b). On general physical examination, no abnormalities were observed except for arthritis of the right ankle and, a few months later, arthritis of the left knee. Biological investigations revealed a raised erythrocyte sedimentation rate with a serum ferritin level at 800 ng/mL (normal < 200 ng/mL), a white blood cell count of 12,500/mm 3 (with 80% neutrophils, 16% lymphocytes, and 4% monocytes), a hematocrit of 40%, and a hemoglobin level of 13.1 g/dL. Electrolytes and liver function tests were normal. Antinuclear antibodies and antibodies to deoxyribonucleic acid (DNA) were negative. Rheumatoid factor was absent. No evidence of the following infections/organisms was found on serologic screening: syphilis, Streptococcus , Toxoplasma , Mycoplasma , Brucella , Borrelia burgdorgferi , spotted fever, leptospirosis, hepatitis B and C virus, parvovirus, human immunodeficiency virus (HIV) 1 and 2, human T‐cell lymphotropic virus (HTLV) 1, Epstein–Barr virus (EBV), cytomegalovirus (CMV), herpes simplex virus (HSV) 6. Immunoglobulin M (IgM) HSV(1+2) by enzyme‐linked immunosorbent assay (ELISA) analysis with 1 year follow‐up was still detected. The articular synovial fluid of the involved ankle and knee was inflammatory but sterile. A bone marrow biopsy specimen revealed no lymphomatous involvement. Abdominal and chest scans were normal. Skin biopsy of a facial nodule showed, in the dermis and in the subcutaneous fat tissue, a dense perivascular and periadnexal infiltrate composed of numerous plasmacytoid histiocytes and large‐ or medium‐sized lymphocytes ( Fig. 2a,b). No epidermal changes, edema in the papillary dermis, or vasculitis were found. Immunofluorescence staining of frozen tissue sections of a facial nodule showed granular deposits of C3. Inguinal lymph node biopsy revealed, in the paracortical area, focal necrosis with a proliferation of transformed lymphocytes, histiocytes, and numerous nuclear debris typical of histiocytic necrotizing lymphadenitis ( Fig. 3a,b). On immunohistochemical staining examination, CD68 was positive in pathologic paracortical areas. Few mononuclear cells were positive for CD3, CD8, and L‐26 ( Fig. 4). Polymerase chain reaction (PCR) amplification did not show human herpes simplex viruses in the skin biopsy specimen, and culture was also negative. 1(a) Clinical aspect: erythematous papulonodules on the face. (b) Clinical aspect: erythematous papulonodules of the upper part of the trunk2(a) Perivascular and periadnexal dense lympho‐ histiocytic infiltrate involving the dermis (hematoxylin and eosin, × 10). (b) Plasmacytoid histiocytic infiltrate in the subcutaneous fat tissue (hematoxylin and eosin, × 100)3(a) Characteristic pale aspect in the paracortical lymph node affected area (hematoxylin and eosin, ×10). (b) Apoptotic plasmacytoid monocytes, nuclear debris, and numerous transformed lymphocytes in lymph node affected zone (hematoxylin and eosin, ×40)4Lymph node immunohistochemical staining: positive for CD68 (×10) On account of the viral herpetic persistent serodiagnosis, a treatment by valaciclovir then aciclovir at a dose of 800 mg/day was administered, but was not efficient. Clinical features improved rapidly with oral prednisolone therapy, 60 mg/day, but a relapse was observed a few weeks later during a decrease in steroid dose.