Non-Hodgkin's lymphoma (NHL) is a malignant neoplasm of lymphocytes that generally occurs within lymph nodes but that may also occur at extra-nodal sites such as the oral cavity. Here, they tend to occur either in the Waldeyer's ring (palatine tonsils, lingual tonsils, and pharyngeal adenoids) or within the jaw bones. Most NHL are of B-cell derivation, although many lymphomas involving the nasal cavity and subsequently the hard and/or soft palate are of T-cell derivation. Burkitt's lymphoma is an unusual high grade lymphoma that occurs in young children (especially in sub-Saharan Africa) and that tends to occur within the jawbones and is associated with EBV.

Histiocytic lymphomas are rare in the oral cavity. Oral NHL (non-Burkitt's type) is a disease of adults. Patients notice a non-tender swelling or mass in the palate or gingiva, or enlargement of the jawbones (usually the mandible) if the lymphoma is intra-osseous. There may be vague pain and discomfort and/or a sensation of pressure. Mandibular lesions may cause mental nerve paresthesia.

The oral presentation may be part of systemic nodal lymphoma in which case lymph nodes (such as in the neck) may be enlarged, firm, and matted. T-cell lymphomas by virtue of their location in the nasal cavity cause nasal stuffiness and epistaxis.

In Stage III and IV disease, fever, weight loss, and night sweats (also called B symptoms) may be present.

Patients who are immunocompromised (eg, patients with combined variable immunodeficiency or AIDS) and those who have immune dysregulation (eg, those with Sjögren syndrome) are prone to developing lymphoma. Patients who have received organ transplants (eg, hematopoietic stem cell or heart transplants) are prone to developing EBV-associated lymphoma.