One year later… Kikuchi's disease

Abstract

Objectives: Kikuchi's disease is a necrotizing lymphadenitis of benign evolution. Although its pathogenesis is unknown, its clinical presentation, evolution and histological characteristics suggest an immune response of T cells and histiocytes to an infectious agent. The authors present a clinical case of a Kikuchi's disease diagnosed one year after infection by Epstein–Barr virus (EBV). Material and Methods: 20-year old female patient with no relevant previous pathologies, came to the ER due to a cervical pain and emergence of a cervical mass. The patient was afebrile upon observation, hemodynamically stable, with palpable hepatomegaly in the abdomen. Analysis with markers of acute EBV revealed positive, while remaining serology showed no anomalies. Abdominal ultrasound confirmed the hepatosplenomegaly and cervical CT scan showed the presence of multiple lymphadenopathies in the deep cervical chains. A lymph node biopsy was performed showing numerous secondary lymphoid follicles and prominent expansion of the paracortical area, given a heterogeneous population of cells comprising large and small lymphocytes and numerous immunoblasts — compatible with EBV viral lymphadenitis. Symptomatic medication led to favourable evolution. Cervical CT scan 6 months later showed no anomalies. One year after onset of symptoms, the patient came again to the ER after 2 weeks of fever (38–39°), cervical pain and appearance of several cervical nodes. Physical examination revealed an increase of cervical volume and hepatosplenomegaly. CT cervical scan showed lymphadenopathy with diffuse areas of necrosis, predominantly on the right side of the cervical. At this point admission for etiological study was decided. Results: During hospitalization, the patient kept a fever that temporarily responded to antipyretics as well as neck pain. The screening performed revealed appearance of leukopenia (1800 leukocytes) and thrombocytopenia (131,000 platelets). Serologies confirmed prior infections with EBV, rubella and parvovitus, while remaining virological and immunological studies came negative. Abdominal ultrasound revealed hepatomegaly. Lymph node biopsy was performed showing parafollicular hyperplasia (T zone) and sinus histiocytosis. Polymorphic nodular infiltrate was revealed composed of abundant histiocytes, some foam cells, monocytoid cells, plasmacytoid dendritic cells, activated lymphocytes and immunoblasts with frequent isolated cell necrosis, cariorrexis and abundant apoptotic bodies. Monocytoid and histiocytic cells predominate with co-expression of CD 68 and myeloperoxidase and activated CD3 + lymphocyte, consistent with necrotizing lymphadenitis, Kikuchi's disease. Discussion: Corticosteroid was administered yielding progressive regression of symptoms. It was concluded that Kikuchi disease was secondary to EBV infection, diagnosed the previous year. The authors would like to stress the importance of ganglion biopsy and histologic examination to confirm the diagnosis. Going forward, long term close follow-up is a key given strong correlation of Kikuchi's disease with auto immune diseases.