Kikuchi’s disease or histiocytic necrotizing lymphadenitis is uncommon disease that first time was recognized in Japan . The etiology of disease is unknown. Clinical features consist with unilateral cervical lymphadenopathy , often with upper respiratory prodrome and associated in some patients with fever . More cases occur in women , commonly under 40 years of age . The involved nodes are usually firm with rubbery , discrete and sometimes
   tender. Occasional patients present with generalized lymphadenopathy , and rarely, hepatosplenomegaly occurs. Diagnosis has been made by surgical biopsy & histological lymphnode appearance .

         The patient was a 27-years-old woman that was admitted in infectious ward of Sina Hospital in 2/1/2001 . The patient had fever since 10 days and about 40 days she had a mass in her left cervical that grew gradually. In physical examination of patient showed erythema of pharynx , no exuda and a mass in left cervical area that was, nontender , rubbery , discrete with size 5´5 cm . Her temperature was 39.6°c. Initial diagnosis were Typhoid
   fever or Infectious mononucleosis. Laboratory tests were relative leukopenia (4000/mm³) with 48% lymphocytosis & 35% Atypical lymphocyte. She was admitted in hospital in date of 1/2/2001 with complients of fever , headache and vomiting . For the patient was performed surgical biopsy with initial diagnosis of lymphoma by specialist surgen. Pathologist was reported kikuchi’s disease ( histiocytic necrotizing lymphadenitis).

          In the diagnositic approach to unilateral cervical lymphadenopathy and atypical lymphocytosis, kikuchi’s disease despite of the other more common cause as lymphoma, infectous mononucleosis should be considered .