Bone marrow transplantation （BMT） is widely used in the treatment of malignant hematological diseases. However, the occurrence of secondary malignancies is known to be a potential complication after BMT. We report a case of multiple oral squamous cell carcinoma （OSCC） concomitant with chronic graft versus host disease （GVHD） after BMT. A 42-year-old man was referred to our department by a hematologist in our hospital for evaluation of a right buccal tumor. He was given a diagnosis of chronic myelocytic leukemia （CML） in 2000. He underwent BMT to treat CML in 2001. Chronic GVHD developed, affecting the oral mucosa, kidney, liver, and skin, after BMT. There were multiple white lesions on the oral mucosa. Biopsy revealed squamous cell carcinoma of the right buccal mucosa and left lower gingiva. He underwent tumor resection under general anesthesia in March 2012. Another OSCC newly developed in the left lower mucobuccal fold in July 2012, and he underwent tumor resection. The patient has shown no evidence of recurrence or metastasis as of 1 year after the first operation.
