When a Small Oral Nodule Matters: Oral Follicular Lymphoma Without Detectable Extraoral Disease
Year: 2026
Type: article
Study design: Case Report
Abstract: Background Follicular lymphoma (FL) is an indolent mature B-cell neoplasm that predominantly involves lymph nodes, whereas oral involvement is uncommon and may clinically resemble benign conditions. Oral FL usually presents as a painless, nonspecific swelling, making recognition particularly challenging. This report describes an extranodal FL presenting as a subtle oral nodule without detectable extraoral disease and highlights the role of careful oral examination in patients with hematologic disorders. Case Report A 42-year-old woman was referred for hematologic evaluation with a 10-kg weight loss over three months and nocturnal fever. Her history included excision of a right lacrimal gland lesion in 2021, diagnosed as reactive lymphoid hyperplasia, and a left gingival lesion diagnosed as marginal zone lymphoma in 2024, for which recommended systemic treatment was not performed. Because she reported a new enlargement in the left mandibular gingival region, she was referred for dental and stomatologic assessment. Oral examination revealed a subtle, approximately 1-cm, firm, mobile nodular lesion in the left mandibular vestibular sulcus. An incisional biopsy was performed. Histopathological examination demonstrated a nodular lymphoid infiltrate composed predominantly of small lymphocytes, with immunohistochemistry showing CD20-positive B cells with diffuse CD10 and BCL6 expression, supporting the diagnosis of extranodal follicular non-Hodgkin lymphoma. Computed tomography of the neck, chest, and abdomen showed no evidence of lymphadenopathy or other sites of disease. The patient remains under hematologic evaluation for definition of therapeutic management. Discussion Oral FL is rare and may present as an asymptomatic, non-ulcerated swelling that can easily be overlooked or interpreted as a benign lesion. In this case, despite systemic symptoms and a previous history of oral lymphoma, conventional staging imaging failed to identify disease outside the oral cavity, while examination by the dental team detected a small and clinically inconspicuous lesion that established the diagnosis. This presentation reinforces that lesion size or innocuous appearance does not predict biological relevance. Careful inspection and palpation of the oral mucosa, particularly in patients with previous lymphoproliferative disorders or unexplained systemic symptoms, may therefore provide diagnostically relevant findings even when conventional imaging is negative. Conclusion Subtle oral lesions may represent the only clinically detectable manifestation of lymphoma. Integration of systematic oral examination into the multidisciplinary assessment of patients with suspected or previous lymphoproliferative disease may facilitate earlier diagnosis of otherwise occult disease.
Institutions: Universidade de São Paulo, Clinics Hospital of Ribeirão Preto
Language: English
Subfield: Pathology and Forensic Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W7223087637