口腔鳞状细胞癌（OSCC）可能发生在齿槽嵴（少数情况下）。吸烟、慢性黏膜损伤和口腔卫生差都与其发病机制有关。它大多发生在男性而非女性，而且下颌骨比上颌骨的比例为3:2。本研究的目的是介绍一个有趣的病例，即齿槽嵴的OSCC由于使用依诺肝素而模仿颌骨骨坏死，从而产生鉴别诊断的困境。一名78岁的女性患者，全口无牙，佩戴全口义齿，因下颌骨残余齿槽嵴前侧（右侧）区域持续4个月的严重疼痛、溃疡性病变而被转诊。病史显示患者长期使用全身类固醇治疗由于结节性硬化症，并且皮下注射使用依诺肝素治疗骨质疏松症，每月一次，持续一年。进行了锥束CT（CBCT）检查，发现有骨吸收，初步诊断为依诺肝素引起的颌骨坏死（ONJ）或肿瘤。进行了活检，并根据组织学检查显示软组织和基础骨骼被异常、融合、致密的恶性鳞状细胞岛侵袭，伴有明显的异型性和大量核分裂，表明为中度分化的OSCC。依诺肝素抑制配体活化因子受体（RANKL）与核因子Kappa的活化因子受体（RANK）的结合，从而降低骨吸收并增加骨密度。然而，依诺肝素可能引发ONJ。暴露骨骼和异常软组织变化的区域可能既类似良性疾病又类似恶性疾病。骨坏死可能模仿OSCC，甚至为OSCC的发展提供合适的基质。在依诺肝素或双膦酸盐相关ONJ（BRONJ）治疗患者中，需要进行活检和骨影像检查以准确确定肿瘤形成的可能性及其边界，尤其是在骨坏死的情况下。版权所有 © 2023，Zisis et al.

Oral squamous cell carcinoma (OSCC) may arise in the the alveolar ridge (in a minority of cases). Smoking, chronic mucosal injuries, and poor oral hygiene are involved in its pathogenesis. It mostly occurs to men instead of women and affects the mandible on a 3:2 ratio to the maxilla. The objective of the current study is to present an interesting case of an OSCC of the alveolar ridge mimicking jaw osteonecrosis due to denosumab, resulting in differential diagnostic dilemmas. A 78-year-old female patient, edentulous and bearing total dentures, was referred with a persistent (four months), severely painful, ulcerative lesion in the anterior lateral (right) region of the residual alveolar ridge of the mandible. Medical history referred to a long-term systemic steroid use due to sarcoidosis as well as the subcutaneous use of denosumab for osteoporosis one/month for one year. Cone-beam CT (CBCT) examination was performed where bone resorption was detected and a differential diagnosis of osteonecrosis of the jaws (ONJs) from denosumab or neoplasia was made. A biopsy was carried out, and the histological examination showed that soft tissues and underlying bone were infiltrated by abnormal, confluent, compact islands of malignant squamous cells with intense atypia and numerous mitoses indicating a moderately differentiated OSCC. Denosumab inhibits the binding of receptor activator of nuclear factor ligand (RANKL) to receptor activator of nuclear factor-kappa (RANK); this decreases bone resorption and results in increased bone density. However, denosumab may induce ONJ. The area of exposed bone and abnormal soft tissue alterations may resemble both benign and malignant diseases. Osteonecrosis may mimic OSCC or may even provide the suitable substrate for the development of OSCC. Biopsy as well as bone imaging examination are required to accurately determine the possibility of neoplastic formation and its boundaries in cases of osteonecrosis especially in patients under treatment with denosumab or bisphosphonate-related ONJ (BRONJ).Copyright © 2023, Zisis et al.