MALToma: a Helicobacter pylori-associated malignancy in transplant patients: a report from the Israel Penn International Transplant Tumor Registry with a review of published literature

BACKGROUND: Mucosa-associated lymphoid tissue lymphoma (MALToma) is a Helicobacter pylori-related tumor of B-cell origin, the malignant potential for which remains to be defined in immunosuppressed patients. METHODS: Review of the Israel Penn International Transplant Tumor Registry identified six cases of gastric MALToma. Patient demographics, management, and outcomes were compared and published literature was reviewed. RESULTS: MALToma developed in six transplant recipients (three kidney, two heart, one kidney-pancreas). All were treated with immunosuppression minimization and therapy for H. pylori, resulting in disease regression in five patients. One patient developed progression to high-grade MALToma despite documented H. pylori eradication, required surgery and chemotherapy, and died, with significant disease at autopsy. CONCLUSIONS: Treatment of MALToma with immunosuppression minimization and anti-H. pylori therapy results in a majority of patients becoming disease free. Observation of malignant degeneration into an aggressive, high-grade lymphoma in one patient indicates the malignant potential. Diligent follow-up of these patients with endoscopy and biopsy is therefore indicated.