The authors report imaging findings of spontaneous thymic hemorrhage, which is a rare entity in infancy, in a 4-month-old boy with congenital factor VII deficiency presented with acute respiratory distress and anemia. Widening of superior mediastinum and left pleural effusion were detected on the chest radiograph. Ultrasound and computed tomography of the chest revealed diffusely enlarged thymus with heterogeneous parenchyma from poorly-defined areas of altered echogenicity or attenuation. Vascular flow was depicted within the abnormal thymus in color-mode sonography. The spontaneous involution of thymic abnormality seen on serial ultrasonography confirmed the diagnosis of thymic hemorrhage, resulting in avoidance of further unnecessary imaging or invasive procedure.

The authors report imaging findings of spontaneous thymic hemorrhage, which is a rare entity in infancy, in a 4-month-old boy with congenital factor VII deficiency presented with acute respiratory distress and anemia. Widening of superior mediastinum and leftpleural effusion were detected on the chest radiograph. Ultrasound and computed tomography of the chest revealed diffusely enlarged thymus with heterogeneous parenchyma from poorly-defined areas of altered echogenicity or attenuation. Vascular flow was depicted within the abnormal thymus in color-mode sonography. Thespontaneous involution of thymic abnormality seen on serial ultrasonography confirmed the diagnosis of thymic hemorrhage, resulting in avoidance of further unnecessary imaging or invasive procedure.