Primary gastrointestinal malignant lymphomas associated with Epstein-Barr virus after heart transplantation.

Gastrointestinal involvement has been reported in 12-21% of post-transplant lymphoproliferative disorders but is unusual in the setting of heart transplantation. We report four post-transplant lymphoproliferative disorders observed among the 174 heart transplant recipients of our series, all of which were primary malignant lymphomas of and confined to the digestive tract. The mean onset time from transplantation was 22 months. Small intestine lesions were present in all four patients, with gastric involvement in one. Histologically, the tumour was monomorphic of immunoblastic type in one case and polymorphic in the three other cases. Analysis of cytoplasmic immunoglobulins demonstrated the presence of a major monoclonal subset in all patients. Epstein-Barr virus genome was found in numerous tumour cells by in situ hybridization. The exclusive localization to the digestive tract and the lymphoepithelial lesions observed in two cases suggest that these lymphoproliferations might originate from mucosa-associated lymphoid tissue.