Background: Recurrent respiratory papillomatosis (RRP) is a rare disease, which is characterised by the growth of papillomavirus-induced papillomas within the respiratory tract. Malignant transformation occurs in less than 1% of the cases. Case presentation: We report a case of human papillomavirus (HPV) type 11-associated juvenile-onset RRP (JORRP) initially diagnosed at the age of two years. Remarkably high copy numbers of HPV11 DNA and antibody titres targeting the capsid protein L1 were detected in the patient's serum. The patient developed squamous cell carcinomas in both lungs and extraordinarily an HPV11 DNA-positive papillary endocardial lesion in the left atrium of the heart, which caused thromboembolic events leading to the patient's death at 19 years old. Conclusion: We here report a severe case of JORRP hallmarked by HPV11 DNAemia and very high antibody titres directed against the major viral capsid protein L1. Furthermore, the extent of malignant transformation and the discovery of a very rare fatal endocardial lesion highlight the unpredictability of JORRP and the complexity of its clinical management.
