This case represents an example of an unusual T-cell lymphoblastic leukemia/lymphoma syndrome associated with eosinophilia and myeloid malignancy in a young boy. This case is one of only five reported ''leukemic'' variants of the disease and demonstrates the importance of considering this poor prognostic diagnosis in pediatric acute lymphoblastic leukemia. This case also illustrates the importance of an interactive multidisciplinary approach to the laboratory evaluation of a leukemia patient. ' 2005 Wiley-Liss, Inc.Key terms: acute lymphoblastic leukemia; acute myeloid leukemia; hypereosinophilic syndrome; g/d cells CASE REPORT A 9-year-old African-American male presented with a 3-week history of persistent low-grade fever, pneumonia, and massive cervical adenopathy despite oral and intravenous antibiotic therapies. He also reported a history of malaise; occasional shortness of breath with exertion; intermittent, spontaneously resolving chest wall pain; and a fleeting erythematous, macular rash. He denied a history of weight loss and night sweats. His initial examination was significant for grossly visible, 3-to 4-cm, matted bilateral cervical lymph nodes, bilateral shotty inguinal nodes, and no hepatosplenomegaly or testicular masses. A hemogram performed at that time demonstrated a normal total white count with 21% eosinophils, 6% blasts, and several vacuolated neutrophils with toxic granulations. Metabolic panel including liver function tests was normal except for high levels of lactate dehydrogenase (1,179 U/L) and alkaline phosphatase (132 U/L). Chest radiograph confirmed bibasilar interstitial pneumonia with no significant adenopathy and no mediastinal mass. The patient was diagnosed with an atypical pneumonia and admitted to the hospital for intravenous antibiotics, close observation, and further evaluation. Inpatient workup showed an acute mycoplasma infection (positive for immunoglobulin M and cold agglutinins and negative for immunoglobulin G) with negative serologic results for Epstein-Barr virus, cytomegalovirus, and human immunodeficiency virus. Purified protein derivative and control panel showed no evidence of tuberculosis or mumps. The patient remained clinically stable on room air with stable blood counts during his 48-h hospital stay before being discharged on oral clarithromycin therapy.One week later, the patient was readmitted due to progressively enlarging cervical adenopathy and respiratory distress. Hemogram showed worsening anemia, persistent blasts (4%), and increased eosinophilia (43%). Sedimentation rate was increased at 97. Repeat chest radiograph showed persistent pneumonia with bilateral perihilar adenopathy. Computed tomograms of the chest, abdomen, and pelvis demonstrated extensive bilateral submental, cervical, supraclavicular, mediastinal, perihilar, axillary, retroperitoneal, mesenteric, and inguinal lymphadenopathies. Multiple, heterogeneous, low-attenuation lesions consistent with lymphoma were noted in the spleen.
