Incidental osteonecrosis in the distal left femur in a case of beta-thalassemia with COVID-19: Role of [99mTc]Tc-MDP whole-body bone scan.

Secondary anemia in hemoglobinopathies like thalassemia can cause expansion of the bone marrow cavities because of compensatory marrow hyperplasia. This case demonstrates spontaneous osteonecrosis of the distal left femur in a patient with β-thalassemia that may be secondary to ischemic infarction secondary to occlusion of the microvasculature within the expanded cancellous bone. This subject was referred to Hazrat Rasool Akram Hospital because of fever, cough, and bone pain. In the CT scan she had scattered peripheral CGO in both lungs due to COVID-19 with two paravertebral masses due to extramedullary hematopoiesis. The patient had also generalized bone pain so the physician asked for a whole-body bone scan and incidentally, we found a cold lesion with a rim of increased uptake in the distal left femur that with bone biopsy it was consistent with osteonecrosis. This case illustrates the importance of performing a whole-body bone scan in β-thalassemia for the management of patients and diagnosis of occult osteonecrosis.