Case Report

Gingival metastasis from thoracic SMARCA4-deficient undifferentiated tumor: a case report

¹ Department of Odontology and Oral Surgery, Dijon-Bourgogne University Hospital, 21000 Dijon, France
² Department of Maxillofacial Surgery, Stomatology and Hospital Odontology, Besançon University Hospital (CHU Besançon), 25000 Besançon, France
³ Department of Anatomy and Pathological Cytology, Besançon University Hospital (CHU Besançon), 25000 Besançon, France
⁴ University of Franche-Comté, SINERGIES, 25000 Besançon, France

^* Correspondence: alexis.lagrost@chu-dijon.fr

Received: 28 May 2025
Accepted: 26 September 2025

Abstract

Introduction: Thoracic SMARCA4-deficient Undifferentiated Tumors (SMARCA4-UT) are rare and aggressive malignancies. This case is unique as it describes the first gingival metastasis from thoracic SMARCA4-UT, emphasizing the diagnostic role of dental professionals. Observation: A 71-year-old man, heavy smoker (50 pack-years), presented with chest pain, dyspnea, weight loss, and a gingival lesion. Oral examination revealed poor oral health with severe periodontitis, trismus, halitosis, pain on palpation, and a 3 cm friable gingival tumor in sector 2. Premolars showed grade 3 mobility and loss of vitality. 3D imaging confirmed tumor extension. CT, PET-CT, revealed thoracic, adrenal masses and multiple metastases. Histopathology confirmed SMARCA4-UT with gingival metastasis. Outcome: The patient's condition deteriorated rapidly, and he died before treatment could be initiated. Conclusion: Dental professionals play a key role in suspecting systemic disease from oral manifestations. This case underscores the importance of considering metastasis in atypical oral tumors.