Pseudotumor of the Maxillary Sinus in a Child with Von Willebrand Disease.

Introduction: Mandibular pseudotumors, also known as blood cysts, are rare complications which occur more frequently in patients with an associated bleeding disorder such as hemophilia.

Case report: We present a case of a 2-year and 6-month-old patient with a hemophilic pseudotumor associated with Von Willebrand's disease, who consulted the emergency room due to spontaneous increase in volume of the left maxillary region, with no previous relevant medical history.

Conclusions: Different imaging studies were carried out to characterize the lesion, providing the necessary information for the correct approach. Due to the low prevalence of this complication, we believe it is of vital importance to understand the adequate management in this patient population.