Patients with Fanconi anemia (FA) are at increased risk of developing squamous cell carcinoma (SCC), a malignant neoplasm that primarily affects the head and neck region. Oral involvement by chronic graft-versus-host disease (cGVHD) after hematopoietic cell transplantation (HCT) is a significant risk factor for this complication. Long-term regular dental follow-up is well established for transplanted patients with active cGVHD. However, there is no consensus regarding the post-transplant period required for monitoring patients without active cGVHD. This study aims to report a clinical case of SCC of the tongue diagnosed seven years after HCT in a patient with FA and with no treatment for oral cGVHD at the diagnosis time.

A 28-year-old male patient underwent haploidentical HCT for FA, with his father as the donor and bone marrow as the cell source. He received cyclosporine for GVHD prophylaxis. Approximately 14 months post-HCT, he developed lichenoid lesions on the bilateral buccal mucosa, upper and lower lips, as well as non-scrapable white plaques on the dorsal and lateral borders of the tongue, associated with discomfort while eating. During the same period, he presented papules on the hands, trunk, and back, treated with topical corticosteroids and reintroduction of cyclosporine. For the oral lesions, dexamethasone 0.4 mg/mL mouth rinse and clobetasol propionate 0.05% ointment were prescribed. The patient was classified as having mild chronic GVHD involving the mouth and skin. After 14 days of treatment, the lichenoid lesions regressed significantly, but the white plaques on the tongue remained unchanged. An incisional biopsy of the dorsal tongue revealed leukoplakia without dysplasia. The lichenoid lesions resolved after six months of topical corticosteroid therapy, but the white plaques persisted, leading to ongoing dental follow-up. Seven years after HCT, the patient—off medication and with no history of tobacco or alcohol use—developed a granulomatous lesion measuring approximately 0.5 cm on the right lateral tongue, with raised borders and a central ulceration. Histopathological examination confirmed a well- differentiated, keratinized, invasive SCC. The patient was referred to a head and neck surgery team for oncological management.

This case highlights the importance of specialized and prolonged dental follow-up in post-allo-HCT patients, particularly those with a history of cGVHD, regardless of disease activity, to enable early diagnosis and appropriate management of potentially malignant oral lesions.