Isolated gingival relapse of acute lymphoblastic leukemia after transplantation.

A patient with a history of precursor B-cell leukemia presented with an isolated ulcerating gum lesion 8 years after allogeneic stem cell transplantation with severe graft versus host disease. A biopsy revealed an undifferentiated malignant hemic lesion. Examinations of the peripheral blood and marrow were normal. Molecular studies confirmed clonal relationship between the gum lesion with the original marrow disease, despite the anatomical, histological and chronological separations.