A child with FactorⅤdeficiency misdiagnosed as a left iliac fossa abscess having novel F5 gene mutation: a case report

Background: Congenital FⅤdeficiency is identified as a rare bleeding disorder (RBD) that is expressed in an autosomal recessive manner and generally occurs in one part per million of the population.This disorder is accompanied by a variety of clinical manifestations. The factorⅤgene variant c.2439delC (p.I814Lfs*23 ) in exon 13 was first reported in this case. Case presentation： A 13-year-old male patient was admitted with a left iliac fossa mass. He was previously diagnosed and managed as having a left iliac fossa abscess in local hospital,which underwent antibiotics and surgical excision.However, his left iliac fossa mass reappeared.The platelet count and function were normal, and both prothrombin time (PT) and activated partial thromboplastin time (APTT) were prolonged. The patient is then considered having congenital factorⅤdeficiency by measuring coagulation factor activity and the diagnosis is confirmed by genetic testing. The patient got the treatment of fresh frozen plasma (FFP) infusion and recovered. Conclusions: : This case report presents a rare occurrence of congenital FⅤdeficiency ,due to a left iliac fossa hematoma mistaken for an abscess,resulting in unnecessary therapy of antibiotics and surgery.It emphasizes that coagulation factor deficiency should be highly suspected for mass of joint combined with coagulation dysfunction.