Malignant transformation of well-differentiated papillary mesothelioma 13 years after the diagnosis: a case report


  • This study did not receive any financial, pharmaceutical or industry support. It was not funded by any of the following institutions: National Institutes of Health (NIH); Wellcome Trust; Howard Hughes Medical Institute (HHMI); and other(s).
  • Authorship and contributorship

    All the authors have substantially contributed to the manuscript. LC, SS, LR and AP took care of the patient, conceived the work and searched the English literature. LC and SS also prepared the draft of the manuscript. GP performed microscopic examination of biopsy samples and created the related image. SS and FMDM performed endoscopy. RAI, AOM and ST provided valuable ideas to the conception of the work and critically revised the manuscript for important intellectual content.

  • Ethics

    This work was created in accordance with the ethical standards of the Declaration of Helsinki.

  • Conflict of interest

    All authors have no conflict of interest to disclose. All authors disclose any actual or potential conflict of interest including any financial, personal or other relationships with other people or organisations that could inappropriately influence (bias) their work.


Well-differentiated papillary mesothelioma (WDPM) is a rare mesothelial tumour affecting mostly the peritoneum of women in their reproductive age, but it may occur also at other sites, including the pleura. It is considered a specific pathological entity different from diffuse malignant mesothelioma as it displays a characteristic histological pattern and is associated with a slowly progressive clinical course. We report the case of a 79-year-old man with a history of right pleural WDPM at age 64, which was successfully treated with chemotherapy, radiotherapy and talc pleurodesis. Thirteen years after the first diagnosis, he presented with mediastinal lymph nodes metastasis and with an extremely rare pattern of tracheal and bronchial infiltration that was detected at bronchoscopy. Biopsy samples revealed loss of histological differentiation of the neoplastic cells. This case report highlights that WDPM is a tumour of uncertain malignant potential that may undergo transformation over many years. Finally, the role of immunohistochemistry in the diagnosis of WDPM and the possible mechanisms leading to this unique way of metastatisation are discussed.