Altaf et al. Journal of Medical Case Reports 2012, 6:141 http://www.jmedicalcasereports.com/content/6/1/141 a b c Page 3 of 6 Figure 1 Bone marrow biopsy and aspirate showing hemophagocytosis and positive staining for CD68 marker for the presence of macrophages. Due to progressive enlargement of the lymph nodes in her cervical region two months after the initiation of therapy, an excisional biopsy of the cervical mass was performed (Figure 2). Pathology results were consistent with EBV-positive diffuse large B-cell lymphoma. EBV viremia at the time of diagnosis of lymphoma was reported at 1,500 copies in the blood (Table 2). Immu- nohistochemistry results were positive for CD20, CD19 and CD79a. A positron emission tomography scan showed extensive involvement of her supraclavicular and cervical lymph nodes as well as some involvement of her liver (Figure 3). A bone marrow biopsy showed no evi- dence of involvement of lymphoma or hemophagocyto- sis. Treatment for lymphoma was given with six cycles of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) based on our institutional standard of care for patients sixteen years of age and older. Treatment related complications included pro- longed fever and neutropenia. Restaging with positron emission tomography at the end of her R-CHOP therapy showed complete resolution. Our patient is now disease- free after completion of therapy. She has been off immu- nosuppressives for her Crohn’s disease since her recov- ery from lymphoma, and has also been in remission for over 24 months now. Discussion This case highlights the importance of making the diag- nosis of HLH in a critically ill patient. The challenge presented in our patient was the limited number of HLH diagnostic criteria, with only a moderate elevation of ferritin noted compared with other patients diagnosed CD68 with HLH [4]. There was absence of a coagulopathy and abnormal triglycerides. Hence, at her initial presentation, she did not fulfill five of the eight criteria. Eventually she fulfilled the required five of eight criteria, including per- sistent fevers, cytopenia, splenomegaly, elevated CD25 and presence of hemophagocytes on a bone marrow bi- opsy. She had elevated EBV serologies and polymerase chain reaction copies. Infection-associated HLH has been reported with EBV, cytomegalovirus, hepatitis A, B and C, parvovirus, human herpes virus 6 and 8, HIV, measles, mumps and rubella. In addition, a variety of bacterial, fungal and protozoan infec- tions have been described [5]. Patients with inflammatory bowel disease on immuno- modulating drugs like azathioprine and 6-mercaptopurine have been reported to develop HLH [6,7]. The diagnosis of our patient’s Crohn’s disease was confirmed by biopsy showing evidence of terminal ileitis. She was on immuno- suppressive therapy for six months with 75mg of 6- mercaptopurine prior to the diagnosis of HLH. Further extensive evaluation for immune deficiencies did not re- veal any associated primary immunodeficiency to be the cause. In our patient, there was no clear evidence of lymph- oma at presentation, with an absence of significant lymphadenopathy on clinical examination and imaging (computed tomography of her chest, abdomen and pelvis). Physical and imaging studies suggested the possi- bility of reactive lymphadenopathy due to EBV viremia and an excisional biopsy was not pursued at initial pres- entation. It is possible that our patient might have pre- sented with smoldering lymphoma at the time of HLH