Oral Hairy Leukoplakia: A Rare Involvement in a Patient with Polycythemia Vera.

Although there have been some reports of oral hairy leukoplakia (OHL) in patients with hematologic neoplasms, to the best of our knowledge, this study is the first to report this lesion affecting a patient with polycythemia vera. A 54-year-old male patient diagnosed with polycythemia vera presented with non-removable white patches with a rough surface on the bilateral border of the tongue. According to clinical, histopathological and in situ hybridization features, OHL was established. Two months after diagnosis, the patient developed splenomegaly and initiated ruxolitinib. Bone marrow biopsy showed post-polycythemia vera myelofibrosis. The patient underwent allogeneic haploidentical hematopoietic stem-cell transplant, achieving complete remission of the oral lesion. OHL is an important marker of immunosuppression. In the present case, OHL was diagnosed during the progression of polycythemia vera to myelofibrosis and its early diagnosis may have contributed to a better clinical outcome.