鼻窦未分化癌(SNUC)是一种罕见的高度侵袭性肿瘤,最常见于上颌窦和鼻腔。口头参与极为罕见。
一名62岁的男性出现一个大的浸润性肿块,累及硬腭和左牙槽脊。计算机断层扫描显示骨破坏和鼻旁窦和眼眶的侵袭。组织学显示,恶性肿瘤由小圆形细胞组成,细胞质最少,核深染,与口腔粘膜上皮无任何联系。免疫组织化学分析显示上皮起源(CK-7+,CK-20+,AE1/AE3+,EMA),并且缺乏鳞状细胞和神经内分泌分化的有力证据(p63-,34βE12-,NSE-/+,嗜铬粒-,突触毒素-)。TTF-1阴性排除转移起源。诊断为SMARCB1(INI1)阳性的SNUC亚型。患者接受同步放疗和化疗,2年后无复发迹象。
涉及口腔的SNUC是一种罕见的恶性肿瘤,可能模仿牙齿感染或鼻窦炎的症状。临床的仔细关联,微观,免疫组织化学特征是早期诊断的必要条件。
Sinonasal undifferentiated carcinoma (SNUC) is a rare tumor highly aggressive most frequently arise in the maxillary sinus and nasal cavity. Oral involvement is extremely rare.
A 62-years-old male presents a large infiltrative mass involving the hard palate and left alveolar ridge. Computed tomography showed bone destruction and invasion of paranasal sinuses and orbits. Histology revealed a malignant neoplasm consisting of small round cells with minimal cytoplasm and hyperchromatic nuclei without any connection with the oral mucosal epithelium. Immunohistochemical analysis showed epithelial origin (CK-7+, CK-20+, AE1/AE3+, EMA+) and lacked strong evidence of squamous and neuroendocrine differentiation (p63-, 34βE12-, NSE-/+, chromogranin-, synaptophysin-). TTF-1 negative ruled out the metastatic origin. A diagnosis of SNUC subtype positive for SMARCB1 (INI1) was reached. The patient was submitted to concurrent radiotherapy and chemotherapy without signs of recurrence after 2 years.
SNUC involving the oral cavity is a rare malignancy that may mimic symptoms of dental infection or sinusitis. A careful correlation of clinical, microscopic, and immunohistochemical characteristics is mandatory for early diagnosis.