A Case of Avascular Necrosis of the Femoral Head as Initial Presentation of Chronic Myelogenous Leukemia
A 21-year-old male patient was presented with pain in the right hip joint for 2 months. He was a soldier and went to the dispensary of the unit that he belonged to. He was referred to our hospital for further evaluation of abnormal complete blood cell count which was performed at the dispensary. The patient suffered from weight loss, mild dyspnea, fatigue, intermittent fever, and night sweat. The further history was uneventful.\nUpon physical examination, it was observed that the patient was in poor general condition with pallor skin and anemic conjunctiva. There were no signs of hemorrhagic diathesis or icterus. The spleen was palpable below the umbilicus and had a firm consistency. Cervical and inguinal lymph nodes were palpable. Heart and lungs were without any pathologic findings. The chest X-ray and electrocardiography were normal.\nLaboratory investigations revealed leukocytosis with leukocyte count of 96,800/mm3, increased platelets with a count of 684,000/mm3, and hemoglobin level of 10.4 g/dL. The peripheral blood smear revealed 1% blast cells. Microbiology findings were sterile cultures of blood and urines.\nBone marrow examination revealed that the entire marrow space was packed with granulocytes and megakaryocytes. The bone marrow biopsy showed marked hypercellularity and the estimated cellularity was near 100%. The bone marrow aspiration showed 0.4% myeloblasts, 6% promyelocytes, 13.2% myelocytes, 15.2% metamyelocytes, 14.7% band neutrophils, 40% segmented neutrophils, 2.7% eosinophils, 0% basophils, 0.8% monocytes, 0.4% pronormoblasts, 0% lymphoblasts, 0% immature lymphocytes, 0.4% lymphocytes, 0.4% plasma cells, and 0% histiocytes suggesting chronic phase of CML. Chromosomal analysis of bone marrow revealed Philadelphia chromosome, t (9;22) and molecular cytogenetics also showed bcr-abl positive.\nTreatment with hydroxyurea was induced, combined with immediate evaluation of right hip joint pain. Radiolucency superimposing the right femoral head was seen on the pelvic X-ray (). Whole body bone scan showed increased uptake of the right hip joint. Magnetic resonance imaging (MRI) of both the hips revealed inhomogenously decreased signal intensity in the both proximal femur and acetabulum on T1 weighted images. The outer areas surrounding these areas had increased signal densities on T2 weighted images (). On application of contrast medium, area with former decreased signal density on the cranial part of the right femoral head and some smaller areas of the left femoral head, showed a lack of signal enhancement. Bilateral joint effusion, worse in the right than the left, was also seen. All together, MRI showed signs of necrosis of both the femoral heads.\nThe leukocyte count decreased from 96,800/ul to 26,300/mm3 with the treatment of hydroxyurea (3 g/day) for 2 weeks and subsequently hydroxyurea was replaced with imatinib mesyalte. With this treatment leukocytes were reduced from 96,800/mm3 to 8,900/mm3 within 3 weeks. The size of the spleen decreased to 3 cm below the costal margin within 1 month.\nFollowing normalization of the peripheral blood counts, the patient was transferred to the department of Orthopedics. He underwent a bipolar hemiarthoplasty of the right hip joint, because the necrosis of the right hip joint was more severe than the left and he had no pain in the left hip joint. The postoperative course was complicated due to bleeding from the operative site possibly due to thrombocytopenia which may have been induced by imatinib mesylate. Temporarily, the medication of imatinib mesylate was stopped, and the patient was transfused with platelets and packed red cells. The biopsy revealed focal subchondral necrotic areas in the right hip joint ().\nThe patient was on a continuous follow up and showed no complications with complete cytogenetic response and has been on medication of imatinib mesylate (400 mg/day).