[Giant hemophilic pseudotumors in brothers with non-severe hemophilia B].

Hemophilic pseudotumors can occur in patients with hemophilia because of recurrent bleeding and poor hemostasis. A man in his 30s with hemophilia B and human immunodeficiency virus/hepatitis C virus co-infection complicated by liver cirrhosis presented with a large pseudotumor in the left iliopsoas muscle. However, resting to stop bleeding was difficult with his daily work. Osteolytic changes in the left ilium progressed over 8 years. A large osteolytic pseudotumor in the pelvis was also incidentally identified in his younger brother during his 30s. The same mutations in F9 (p. Arg294Gln, hemizygous mutation) associated with a non-severe phenotype were detected in both brothers. The clinical courses of the brothers suggested that large pseudotumors can occur in patients with non-severe hemophilia and underline the importance of patient education.