Muramatsu Aya, Hasegawa Hiromasa, Kusafuka Kimihide, Suzuki Makoto
Department of Pathology, Shizuoka General Hospital, Shizuoka, JPN.
Center for Clinical Pathology, Fujita Health University Hospital, Toyoake, JPN.
Cureus. 2023 Apr 18;15(4):e37796. doi: 10.7759/cureus.37796. eCollection 2023 Apr.
Carcinoma cuniculatum (CC) is extremely rare in the maxilla. Here, we report a case of CC arising from an oroantral fistula (OAF). The patient was a 70-year-old Japanese man who was followed up for a non-closing OAF. Although there were no findings based on an intraoral examination, follow-up contrast-enhanced computed tomography and magnetic resonance imaging showed a 22-mm mass in the maxilla close to the OAF. Histologically, cystic and endophytic papillary proliferation of squamous epithelium with abundant keratinization mimicking rabbit burrows occupied the alveolar bone. This tumor was directly connected to the atypical proliferation of the covering epithelium of the OAF. The tumor cells showed mild cytological atypia and a few mitoses. Finally, the patient was diagnosed with CC arising from an OAF. CC is often misdiagnosed; nonetheless, the unique endophytic, branching, and tunnel-like structure is a hallmark of this tumor. We present the first well-documented case of CC arising from an OAF, discuss its diagnostic features, and highlight its differences from other common benign and malignant pathological entities.
上颌骨的兔穴状癌（CC）极为罕见。在此，我们报告一例源自口腔上颌窦瘘（OAF）的CC病例。患者为一名70岁的日本男性，因OAF未闭合而接受随访。尽管口腔检查未发现异常，但后续的增强计算机断层扫描和磁共振成像显示上颌骨靠近OAF处有一个22毫米的肿块。组织学上，鳞状上皮呈囊性和内生性乳头状增生，伴有大量角化，类似兔穴，占据牙槽骨。该肿瘤与OAF覆盖上皮的非典型增生直接相连。肿瘤细胞显示轻度细胞学异型性和少量有丝分裂。最终，患者被诊断为源自OAF的CC。CC常被误诊；尽管如此，其独特的内生性、分支状和隧道样结构是该肿瘤的标志。我们呈现了首例有充分记录的源自OAF的CC病例，讨论其诊断特征，并强调其与其他常见良性和恶性病理实体的差异。
