A case of recurrent respiratory papillomatosis with malignant transformation, HPV11 DNAemia, high L1 antibody titre and a fatal papillary endocardial lesion

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.