Immune deficiency and dysregulation-associated lymphoproliferative disorders encompass a heterogeneous group of conditions. In the oral cavity, they are better represented by polymorphic lymphoproliferative disorders, which are microscopically characterized by the presence of lymphoid cells, plasma cells, and Hodgkin/Reed-Sternberg-like cells, as well as angioinvasion and tissue necrosis, but not fulfilling the criteria for a lymphoma diagnosis. It occurs following a depletion of T-cell immunosurveillance, and it may regress if the immunological status of the patient is reestablished. Infection by EBV is very common, but this virus is absent in up to 40% of the cases. In the oral and maxillofacial region, these lesions more often affect the gingiva, the tongue, the palate, and other less common sites can also be affected. Oral lesions may range from mucosal hyperplasia to painful mucosal ulcerations covered by yellowish necrosis or fibrinopurulent membrane, usually with a short period of duration, and a strict clinical and pathological correlation is necessary for correct diagnosis. In mild lymphoproliferative disorders, if the immunological status is restored, patients often go into remission, but in more severe lymphoproliferative disorders, surgery, radiotherapy, and chemotherapy may be necessary, depending on the subtype diagnosed.