Association of hereditary haemorrhagic telangiectasia (Rendu-Osler-Weber syndrome) and malignant melanoma in two patients

Hereditary haemorrhagic telangiectasia in a patient taking anticoagulant drugs who has sustained facial trauma

The authors present the case of a 41-year-old patient with hereditary hemorrhagic telangiectasia (HHT), who in the past had an aortic valve replacement surgery, currently takes anticoagulant drugs and has sustained an extensive trauma to the nose as a result of a dog bite. The HHT is diagnosed basing on the presence of at least three out of four symptoms or signs: spontaneous epistaxis, vascular lesions in the internal organs, skin telangiectasias and a family history of the disease. The presented patient showed hepatic angioma, history of recurrent bleeding from the tongue and spontaneous epistaxis as well as numerous skin telangiectasias. In his case, HHT coincided with chronic treatment with coagulants implemented after an implantation of the artificial aortic replacement valve, what substantially modified the clinical picture and course of treatment.

Immunohistochemical analysis of a merkeloma observed in a patient affected by hereditary haemorrhagic telangiectasia

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by epistaxis, telangiectases, and multiorgan vascular dysplasia. Mutations of the ENG and ACVRL1 genes cause at least 80% of cases. We report the first case of merkeloma found in a patient with HHT carrying an ENG mutation. We analysed the tumour with immunohistochemical methods using primary antibodies against CD105 (endoglin), TGF-β, Smad4, CD31 and CD34. Tumour cells were positive for Smad4, weakly positive for TGF-β, and negative for CD105. Vasal endothelial cells were highly positive for CD105, CD31 and CD34. No remarkable differences between cancer and normal cells in our patient or between the patient's merkeloma and two control merkelomas were observed. The presence of a merkeloma in an HHT patient could be an occasional association, but to certainly assume it further investigations are needed.