In situ buccal carcinoma in a teenager after hematopoietic stem cell transplantation: A case report

RATIONALE: Hematopoietic stem cell transplantation (HSCT) is the most effective treatment for the majority of patients who have malignant haemolytic disease. Although the success rate of HSCT has increased, the increasing number of cases suffering from secondary solid malignancies after HSCT has attracted more interest recently. PATIENT CONCERNS: A 16-year-old female patient from China presented with a crusty and painful lesion on the left buccal mucosa with a history of chronic graft-versus-host disease following allogeneic HSCT for acute myeloid leukaemia. DIAGNOSIS: An incisional biopsy of the lesion showed stratified squamous epithelium mucosa with severe dysplasia (carcinoma in situ). Subsequently, a wide local excision was performed and histological examination revealed early infiltrating squamous epithelial mucosa (carcinoma in situ). INTERVENTIONS: She was being treated in the oral and maxillofacial surgery clinic with an incisional biopsy of the left buccal mucosa. She also received a wide local excision. OUTCOMES: Follow-up for 4 years showed no recurrence. LESSONS: This case helps raise awareness of the diagnosis of oral symptoms in young patients after HSCT. Due to the increasing application of HSCT, raising awareness in oral and dental physicians may be required to improve long-term clinical outcome of patients who underwent HSCT.