Poor management of either type 1 diabetes or haemophilia A can lead to complications such as organ dysfunction and haemarthropathy. Here, we describe the case of an 8-year-old boy diagnosed with severe haemophilia A shortly after birth. At 2 years old, he was also diagnosed with type 1 diabetes. After six years, the haemophilia treatment was changed from a plasma-derived factor VIII (FVIII) concentrate (octanate®, Octapharma, Lachen, Switzerland) to Nuwiq® (simocotocog alfa, Octapharma, Lachen, Switzerland), a recombinant FVIII (rFVIII) product from a human cell line, which allowed for a personalised treatment schedule that supported good adherence. The dosing regimen could be reduced to two weekly rFVIII infusions. The patient has experienced no spontaneous bleeds since switching to rFVIII and shows no signs of joint damage after over seven years of FVIII prophylaxis. rFVIII was well tolerated, with no treatment-related adverse events observed. This case illustrates the importance of treatment personalisation for young patients and their families managing concomitant diseases.

An increased incidence of haematologic malignancies and other cancer types among patients with haemophilia compared with matched controls has been reported in several longitudinal studies. Tumours initially misdiagnosed as haematomas and conversely haematomas mistaken for tumours have been reported. Here, we describe the case of a 43-year-old man with severe haemophilia A and a diffuse large B-cell lymphoma, originally diagnosed as a haematoma, who underwent a splenectomy and several associated surgeries as part of his lymphoma treatment. Perioperative treatment with octanate® (human coagulation factor VIII) enabled the successful performance of all surgical interventions required in the context of lymphoma treatment. Nevertheless, differential diagnosis of posttraumatic haematoma in patients with haemophilia should include the consideration of malignancy.