A 40 year old Pakistani woman presented with one month history of fever, night sweats, and progressive and painful swelling in the right side of the neck. She was febrile (temperature 38-40ºC). Right deep cervical, occipital, and jugulodiagastric lymph nodes were palpable, firm, and tender. Save for a moderately severe asymmetrical arthralgia of right wrist, shoulder and proximal interphalangeal joints, the rest of her physical examination was unremarkable. Laboratory data showed, mild leucopenia of 3.6 × 10 9 /l with 64% neutrophils, 26% lymphocytes (no atypical form), and 10% monocytes, erythrocyte sedimentation rate (ESR) 64 mm/hour, and C reactive protein of 105 mg/l (normal <10 mg/l). A skin test for tuberculin reactivity was negative. Results of chest radiography, blood chemistry, urine and stool analysis, throat swab, blood cultures, Venereal Disease Research Laboratory test, test for HIV, heterophil antibodies, and serological studies for salmonella serotypes, brucellosis, toxoplasmosis, Lyme disease, Epstein-Barr virus, cytomegalovirus, human T cell leukaemia Answers on p 663.