Primary Non-Hodgkin Lymphoma of Palatal Gingiva

Non-Hodgkin lymphomas (NHLs) are a heterogeneous group of lymphoproliferative malignancies that can disseminate to organs and tissues that do not ordinarily contain lymphoid cells (extranodal sites). Primary extranodal NHL of the oral cavity is rare, and gingiva is one of the rarest intraoral sites involved. The majority of oral NHLs reported are of diffuse large B-cell type. Such lymphomas are more prevalent in immunocompromised patients. Because of their malignant nature, early recognition, diagnosis, and treatment are essential for a patient's survival. To the best of our knowledge, this report presents the first case of diffuse mixed small and large B-cell lymphoma involving the gingiva in a non-immunocompromised patient.

A female patient presented with a growth located on the palatal aspect of the right maxillary molar region involving marginal and interdental gingiva. Routine laboratory tests and clinical examination were within normal limits. An incisional biopsy of the gingival tissue was evaluated using histologic techniques and immunohistochemistry. A diagnosis of extranodal diffuse mixed small and large B-cell lymphoma was established. The patient underwent a complete workup to rule out other systemic lesions, thereby supporting the primary nature of the lesion.

Gingival overgrowth may rarely be the first manifestation of extranodal NHL. Only histopathological examination of the specimen with immunohistochemistry can ascertain a confirmed diagnosis of NHL. The present case report stresses the importance of routine biopsy examination for growth lesions of long duration when an infectious etiology has been ruled out, even if the lesions appear benign.