Delayed Massive Expansion of Subgaleal Hematoma Complicated with Proptosis in Hemophilia B

Proptosis after a subgaleal hematoma (SGH) is a rare condition that may require immediate intervention to prevent visual loss. A 12-year-old boy presented with localized SGH in the left parietal area after hair-pulling. The SGH was massively expanded on the entire scalp on the 3rd day of the trauma. On the next day after the massive expansion, proptosis of the right eye occurred suddenly. Emergent needle aspiration of the SGH was performed, and the proptosis improved slightly. Fortunately, his vision did not deteriorate. After all, he was diagnosed with coagulation factor IX deficiency (hemophilia B). The supraorbital notch could be a passage of the SGH to extend into the subperiosteal space of the orbit.