Detection of Epstein-Barr virus DNA in a patient with Kimura's disease.

Abstract

An 80-year-old man, with a past medical history of senile dementia, presented with a 6-month history of a solitary, gradually enlarging tumor, located on his chin. A squamous cell carcinoma had been surgically excised 30 years previously in the same location. Physical examination revealed an erythematous, well-defined plaque of 3 cm in diameter, located on the chin (Fig. 1). The submandibular lymph nodes were enlarged. Squamous cell carcinoma and primary cutaneous lymphoma were considered. Relevant laboratory findings were as follows: white blood cell count, 5.600/microL; eosinophils, 1000/microL; gammaglobulin, 2.4 g/dL; lactate dehydrogenase, 343 IU/L; and immunoglobulin G (IgG) antibodies to Epstein-Barr virus (EBV) positive (at 1 : 128 serum dilution), with negative IgM. Skin and lymph node biopsies were performed. Histopathologic study of the cutaneous specimen revealed a heavy lymphoid infiltrate with numerous lymphoid follicles, with prominent germinal centers involving the subcutaneous fat as well as the deep dermis and muscular fascia. Some germinal centers showed folliculolysis. The lymphoid follicles were surrounded by fibrous tissue. The interfollicular infiltrate was rich in plasma cells and eosinophils that formed scattered eosinophilic microabscesses. Thin-walled vessels were numerous and prominent, but with no epithelioid or vacuolated endothelial cells (Fig. 2). Histopathology of a lymph node biopsy specimen showed reactive lymphoid follicle hyperplasia, with prominent eosinophilic infiltrates in both follicular and interfollicular areas. Eosinophilic deposits and polykaryocytes of Warthin-Finkeldey type were seen in the germinal centers. The paracortical area showed vascular proliferation. Polymerase chain reaction (PCR) for the detection of specific sequences of EBV from routinely processed paraffin-embedded material was carried out under the conditions and with the same set of primers as described previously in detail (Tenorio A, Echevarría JE, Casas E et al. J Virol Methods 1993; 44: 261-269). DNA samples were confirmed to be amplifiable with PCR primers specific for a conserved region of the human beta-globin gene. Every sample was tested at least twice for EBV DNA and beta-globin gene. One sample from one skin lesion of the patient, with confirmed diagnosis of Kimura's disease, and 10 samples from normal skin biopsies retrospectively collected from other patients in archival files of our department were tested. Only the patient's specimen tested positive to EBV. The amplified product of EBV was analyzed using DNA sequencing and confirmed the results obtained. The patient received radiotherapy at doses of 35 Gy. Nevertheless, the tumor enlarged to reach twofold its original size 1 month later. Due to the physical status of the patient, no further treatments were considered, but the disease remained stable over the following 3 years.