P16-positive secondary tongue squamous cell carcinoma following allogeneic hematopoietic stem cell transplantation: A case report and literature review.

As a method to improve the survival rate of patients with hematological malignancies, allogeneic hematopoietic stem cell transplantation (allo-HSCT) has increasingly been used for treatment. However, some potentially serious complications after allo-HSCT, including graft-versus-host disease, graft failure, infection, end-organ toxicity, and secondary malignancies, will determine the success of hematopoietic reconstitution. Here, we describe a case of a patient with p16-positive tongue squamous cell carcinoma (TSCC) following allo-HSCT. A 62-year-old man who had previously received allo-HSCT due to acute lymphocytic leukemia (AML) presented with erosions on the back of the tongue surrounded by multiple white patches, which were compatible with oral chronic graft-versus-host disease (cGVHD). During follow-up, a circular-like erosive lesion appeared on the right dorsal surface of the tongue. Biopsy of this lesion confirmed early invasive TSCC (T2N0M0). Partial glossectomy and tongue reconstruction were performed after cessation of immunosuppressants. Immunohistochemical (IHC) staining was positive for p16 and ki-67, suggesting a probable active human papillomavirus (HPV) infection. Six months after surgery, the patient showed no signs of metastasis or recurrence nor progression of oral GVHD.