Kim Min Kyeong, Hertz Peter, Woo Sook-Bin
Department of Oral Medicine Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA.
Atlantic Coast Oral Maxillofacial Surgery, P.C., Swansea, MA, USA.
Head Neck Pathol. 2025 Jul 14;19(1):85. doi: 10.1007/s12105-025-01819-6.
SMARCA4-deficient high-grade malignancies are increasingly recognized across various anatomic sites, namely the genitourinary tract thorax, gastrointestinal tract, head and neck, and central nervous system. Within the head and neck region, the sinonasal tract is most commonly affected. These tumors are aggressive, often presenting with local or distant metastases at diagnosis, and median survival ranges from 4 to 7 months. We report a rare case of SMARCA4-deficient carcinoma presenting as a metastasis to the oral cavity, highlighting key histopathologic and clinical features.
A 63-year-old woman presented with a 3.0 × 2.0 × 2.0 cm exophytic mass involving teeth #25-28 and a 4 cm poorly defined radiolucency in the mandible. Histologically, the tumor was composed of diffuse sheets of large polygonal epithelioid cells with indistinct borders, pale eosinophilic cytoplasm, vesicular pleomorphic nuclei, prominent nucleoli, and numerous atypical mitotic figures and apoptotic bodies. Immunohistochemistry showed focal positivity for pankeratin, CAM5.2, and claudin-4. The tumor was negative for S100, SOX10, and SMARCA4 (BRG1), confirming SMARCA4-deficiency. A CT scan revealed a 5.5 cm mandibular lesion and a 16 cm right upper lobe lung mass, with additional nodules in the contralateral lung, thyroid, kidney, and widespread lymphadenopathy. The findings were consistent with a primary thoracic SMARCA4-deficient undifferentiated tumor with diffuse metastases. The patient died within two months of initial diagnosis of the oral metastasis.
To our knowledge, this is the first reported case of this unusual tumor metastasizing to the oral cavity. Given the aggressive nature and metastatic potential of these tumors, it is essential to evaluate for a distant primary malignancy when such a lesion is encountered in the head and neck.
SMARCA4缺陷型高级别恶性肿瘤在各个解剖部位越来越多地被认识到，包括泌尿生殖道、胸部、胃肠道、头颈部和中枢神经系统。在头颈部区域，鼻窦道最常受累。这些肿瘤具有侵袭性，在诊断时常常出现局部或远处转移，中位生存期为4至7个月。我们报告了一例罕见的SMARCA4缺陷型癌转移至口腔的病例，突出了关键的组织病理学和临床特征。
一名63岁女性，出现一个3.0×2.0×2.0 cm的外生性肿物，累及25 - 28号牙齿，下颌骨有一个4 cm边界不清的透射区。组织学上，肿瘤由弥漫性大片状大的多边形上皮样细胞组成，细胞边界不清，胞质淡嗜酸性，核呈泡状、多形性，核仁明显，有大量非典型有丝分裂象和凋亡小体。免疫组化显示泛角蛋白、CAM5.2和claudin - 4局灶阳性。肿瘤S100、SOX10和SMARCA4（BRG1）阴性，证实为SMARCA4缺陷。CT扫描显示下颌骨有一个5.5 cm的病变以及右上叶有一个16 cm的肺肿物，对侧肺、甲状腺、肾脏有额外结节，并有广泛淋巴结病。这些发现符合原发性胸部SMARCA4缺陷型未分化肿瘤伴弥漫性转移。患者在口腔转移初步诊断后两个月内死亡。
据我们所知，这是首例报道的这种不寻常肿瘤转移至口腔的病例。鉴于这些肿瘤的侵袭性和转移潜能，当头颈部遇到这样的病变时，评估远处原发性恶性肿瘤至关重要。
