Gingival infiltrates, oral infection, and/or bleeding disproportionate to local etiology can indicate possible relapsed disease. Painless unilateral lymphadenopathy can also represent relapse in patients with previously treated lymphoma.

Incidence of second malignancy can increase as cancer patients live longer. Previous exposure to chemotherapy and radiation and alterations in immune function, graft-versus-host disease (GVHD), and GVHD therapy collectively contribute to risk for second malignancy. Oral squamous cell carcinoma is the most frequently occurring secondary oral malignancy in transplant patients, with the lips and tongue being the most frequently reported sites.