Anaplastic large cell lymphoma in gingiva: case report and literature review.

We report an unusual case of gingival anaplastic large-cell lymphoma (ALCL) that occurred in a 76-year-old Japanese woman who showed marked gingival swelling in both the maxilla and mandible. Although the patient received caries and periodontal therapy at the outpatient clinic of our dental hospital, the gingival swelling remained and she was referred to the oral surgery department, where a biopsy of the gingiva was performed. The specimens showed proliferation of large atypical and amphophilic epithelioid cells beneath the covering epithelium. Immunohistochemical analysis of the proliferating cells revealed positivity for CD30 and T-cell markers, such as CD45RB, as well as CD45RO antibodies, and they were weakly positive for the granzyme B antibody. In contrast, the tumor cells were negative for all B-cell markers as well as for CD3, CD56, S-100 protein, epithelial membrane antigen, and p80(NPM/ALK) antibodies. Based on the clinical and histopathologic features, the lesion was diagnosed as an ALCL in both the upper and the lower gingiva. This is an extremely rare case, in which a specific subtype of T-cell lymphoma appeared in the oral cavity.