BACKGROUND: Fever of unknown origin and high sedimentation rate are common clinical problems. MATERIAL AND METHODS: A middle-aged man with fever of unknown origin, night sweats and high sedimentation rate was referred to our hospital for investigation. RESULTS AND INTERPRETATION: The patient was suspected to have mononucleosis or reactivation of infectious mononucleosis because of mild anaemia and thrombocytopenia, a weakly positive IgM antibody test for Epstein-Barr virus and monocytosis (in peripheral blood). Because monocytosis, elevated sedimentation rate and fever persisted, bone marrow smears were prepared and biopsies taken.The third biopsy showed that morphology was consistent with chronic myelomonocytic leukemia (CMML), which was confirmed by two later biopsies. However, a malignant cell population (consisting of blasts in peripheral blood) was only found in one of several flow cytometry assessments of peripheral blood and bone marrow aspirate and cytogenetic analyses of bone marrow cells were normal. The patient's clinical situation has been stable for some years and treatment has not been necessary.
BACKGROUND:Fever of unknown origin and high sedimentation rate are common clinical problems. MATERIAL AND METHODS: A middle-aged man with fever of unknown origin, night sweats and high sedimentation rate was referred to our hospital for investigation. RESULTS AND INTERPRETATION: The patient was suspected to have mononucleosis or reactivation of infectious mononucleosis because of mild anaemia and thrombocytopenia, a weakly positive IgM antibody test for Epstein-Barr virus and monocytosis (in peripheral blood). Because monocytosis, elevated sedimentation rate and fever persisted, bone marrow smears were prepared and biopsies taken.The third biopsy showed that morphology was consistent with chronic myelomonocytic leukemia (CMML), which was confirmed by two later biopsies. However, a malignant cell population (consisting of blasts in peripheral blood) was only found in one of several flow cytometry assessments of peripheral blood and bone marrow aspirate and cytogenetic analyses of bone marrow cells were normal. The patient's clinical situation has been stable for some years and treatment has not been necessary.