Unusual lymphoproliferative oropharyngeal lesions in heart and heart-lung transplant recipients. Three unusual cases of oropharyngeal lympho-proliferative lesions were seen in recipients of heart and heart-lung transplants. Two caused acute upper respiratory obstruction necessitating urgent ENT intervention. All patients were receiving immunosuppressive drugs including cyclosporin. The two obstructive cases were adenotonsillar enlargement in a 6-year-old, and a tumour of the tonsil and tongue base with cervical lymph node enlargement in a 32-year-old male. Both were caused by Epstein-Barr Virus-associated lymphoproliferative disorder. The third patient, a 32-year-old female, had a presumed low grade T-cell lymphoma that regressed spontaneously. Histopathological diagnosis of these lympho-proliferative disorders after transplantation usually requires immunocytochemistry to distinguish polyclonal proliferative disorders from true lymphoma. Polyclonal lymphoproliferative disorders after transplantation do not usually require aggressive cytoreductive therapy, but respond to simple measures such as the reduction of immunosuppression. 