Extensive Osler-Rendu Disease in a Breast Cancer Patient: Increasing Hepatic Arteriovenous Malformations under Endocrine Therapy Mimicking Liver Metastases

Background: Undefined, increasing hepatic lesions are a common issue in the follow-up care of breast cancer patients and frequently result in invasive diagnostic procedures. Case Report: This case report describes the diagnostic approach in the case of a 58-year-old breast cancer patient with a previously unknown visceral involvement of Osler-Rendu disease. The patient was admitted to our institution because of newly diagnosed, increasing hepatic lesions occurring during endocrine treatment with aromatase inhibitors. On the basis of ultrasound findings, secondary liver metastases were suspected. After a thorough clinical and imaging examination, we reviewed the literature on typical radiological findings of visceral involvement of Osler-Rendu disease, and the impact of endocrine treatment on arteriovenous malformations. Multislice computed tomography scan identified the hepatic lesions as arteriovenous malformations. In the current literature, there are no reports available on the interaction between aromatase inhibitors and arteriovenous malformations. However, some data do show an effect of endocrine therapy with estrogen/progesterone, or tamoxifen on arteriovenous malformations, although some of the results are partially contradictory. Conclusion: This case report demonstrates that for undefined hepatic lesions in breast cancer patients, extensive Osler-Rendu disease should be considered as a potential differential diagnosis. Furthermore, we discuss the possible influence of aromatase inhibitors on arteriovenous malformations.