Hemophilic pseudotumor causes hematoma mainly in the joints and muscles of hemophilia patients. It rarely occurs in the jawbone. We describe our experience with a hemophilic pseudotumor in the maxilla of an infant aged 1 year, 4 months. The patient was being followed-up for severe hemophilia B in our hospital’s department of pediatrics. At the initial visit, swelling of the buccal gingiva of the maxilla second deciduous molar was observed, and CT images showed a tumor in the maxillary left molar region. After the examination, repeated bleeding from the gingival sulcus due to mobility of the maxillary second deciduous molar occurred. Therefore, following the guidelines, we administered a blood coagulation factor IX preparation and extracted the maxillary second deciduous molar under local anesthesia. About 1 month later, we removed the maxillary lesion with the patient under general anesthesia. The lesion was covered with a thin capsule and filled with blood, and the crown of the maxillary first molar was contained within the lesion. The histopathological findings showed internal blood retention and reactive granulation augmentation. The lesion was diagnosed as a hemophilic pseudotumor. The postoperative course has been good with no recurrence of the lesion for 2 years.
