Features of oral peripheral T-cell lymphoma, not otherwise specified

Objective·To investigate the clinical manifestations and immunophenotypic features of peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), involving the oral cavity.Methods·The medical histories and pathology records of patients diagnosed with oral PTCL-NOS in the Department of Oral Mucosal Diseases of Shanghai Ninth People′s Hospital, Shanghai Jiao Tong University School of Medicine, between August 2020 and August 2024 were retrospectively analyzed. In addition, 5 databases, including PubMed, Web of Science, Embase, Scopus, and CNKI, were searched, and relevant cases reported internationally from January 2014 to September 2024 were reviewed.Results·A total of 20 oral PTCL-NOS cases were included, comprising 11 males (55.0%) and 9 females (45.0%). The patients′ ages at initial diagnosis ranged from 25 to 77 years, with a mean age of (52.53±12.94) years. The most common sites were the tongue (25.0%), palate (25.0%), and buccal mucosa (20.0%). Nineteen cases (95.0%) had no B symptoms. The cases were positive for CD3 (19/19), CD4 (11/13), CD8 (7/12), CD2 (5/6), CD7 (5/5), TIA-1 (6/7), GB (9/13), perforin (4/6). EBER expression was negative (8/8). The Ki-67 proliferation index was ≥60% in 85% of cases.Conclusions·Oral PTCL-NOS is extremely rare and has an aggressive clinical behavior. The oral manifestation presents as deep and large mucosal ulcers with uneven bases, and nodules can be palpable. The pathological features are heterogeneous. Immunophenotype detection is useful for early diagnosis and classification. It is essential for stomatologists to enhance their awareness of this malignancy to avoid delayed diagnosis and treatment.