Case report: Von Willebrand disease (VWD), caused by a deficiency or dysfunction of the von Willebrand protein (VWF), presents with a wide range of clinical manifestations. VWF is known to play a role in both platelet adhesion and angiogenesis. Consequently, defective angiogenesis can lead to angiodysplasia, particularly in the gastrointestinal system, occurring in 2-5% of VWD cases, typically in adults. Herein, we present what is, to our knowledge, the youngest reported case of a patient diagnosed with VWD following a presentation of gastrointestinal bleeding secondary to angiodysplasia.

A 2-year and 10-month-old female patient was admitted to our hospital for melena and hematemesis. Her medical history was unremarkable, with no reported fever, diarrhea, or use of anti-inflammatory medications. There was no consanguinity between the parents, and no known family history of bleeding diathesis, Türkiye.

Upon physical examination, the patient was lethargic, weak, and pale. A cardiac murmur was noted. Several 0.5 cm ecchymoses were present on her legs, though petechiae were absent. Initial laboratory tests revealed severe anemia (hemoglobin 3.5 g/dL). Her platelet count was within the normal range, as was her INR (0.96; normal range: 0.8-1.2). However, a prolonged aPTT (46.4 s; normal range: 20-34 s) and a bleeding time greater than 5 minutes were noted. An erythrocyte transfusion was immediately administered.

Treatment with somatostatin and tranexamic acid was initiated. Despite this, the patient experienced three more episodes of bright red bleeding and required two additional erythrocyte transfusions. An upper endoscopy was performed, revealing no esophageal varices. A 2 × 3 cm angiodysplastic lesion was observed in the gastric corpus and was cauterized with an argon laser. A scintigraphy scan confirmed increased activity in the same area. Following the procedure, a fresh frozen plasma transfusion was administered and propranolol treatment was started.

With the bleeding controlled, and given the concurrent angiodysplasia, a detailed work-up for coagulopathy was performed. The patient's von Willebrand factor activity was below 5%, the von Willebrand factor antigen was below 3%, and Factor VIII was less than 3.5%. Platelet aggregation tests were normal. Genetic analysis of the VWF gene identified a novel homozygous mutation, c.7176T>G p.(Tyr2392Ter), and a heterozygous mutation, c.817C>G p.(Ar273Gly). Considering the clinical presentation, laboratory findings, and genetic analysis in a patient with no parental bleeding history, a diagnosis of Type 3 von Willebrand disease was established.

Gastrointestinal bleeding due to angiodysplasia in VWD is a well-known complication that typically arises in adults. The only previously reported pediatric case was by Aggoune et al., who described a 14-year-old with Type 3 VWD and duodenal angiodysplasia who required surgical resection for recurrent bleeding. In contrast, our patient's initial bleeding episode was successfully managed with a combination of argon laser cauterization and medical therapy.

This case highlights the importance of considering VWD in pediatric patients who present with severe gastrointestinal bleeding, especially when routine coagulation tests show a prolonged aPTT and bleeding time in the absence of risk factors for esophageal varices. It also serves as a crucial reminder that angiodysplasia is a known complication of VWD that can present even in the youngest of patients