Abstract: Objective To investigate the clinical manifestations and pathological features of parotid gland papillary acinic cell carcinoma metastasis to left cavernous sinus. Methods  The clinical manifestations, pathological features and differential diagnosis were studied in one case of parotid papillary acinic cell carcinoma metastasis to left cavernous sinus. Related literatures were also reviewed. Results The patient was a 50-year-old female who presented paroxysmal dizziness for 5 months and blurred vision in her left eye for 10 months. The MRI examination showed left parasellar space-occupying mass in the cavernous sinus. In operation, the tumor was located in the superior wall of left cavernous sinus, soft and red-grey in color, with abundant blood supply. The histomorphological examination revealed the tumor cells were arranged in solid, acinar or papillary pattern. The tumor cells were large, with eosinophilic cytoplasm, round or oval nuclei and small nucleoli. Immunohistochemical staining found that the tumor cells expressed cytokeratin (CK), epithelial membrane antigen (EMA), vimentin (Vim) and S-100 protein (S-100), and showed weak positive expression of glial fibrillary acidic protein (GFAP) and focal positive expression of P53 protein. Ki-67 labeling index was about 5%-10% . The tumor cells were negative for neuroendocrine markers and pituitary hormone protein markers. This case was difficult to differentiate from other primary intracalvarium tumors, including papillary meningioma, papillary tumor of choroid plexus, papillary ependymoma, papillary glioneuronal tumors as well as chordoma. According to the medical history and the comparison of histomorphology and immunophenotyping between parotid gland tumor cells and left cavernous sinus tumor cells, the final diagnosis was metastatic papillary parotid acinar cell carcinoma of the left cavernous sinus. The patient was followed for 21 months and no recurrence was seen. Conclusion  It is very rare and to our knowlege it is the second case with metastasic papillary parotid acinar cell carcinoma in the cavernous sinus. Understanding the patient's history and differentiating from other primary intracalvarium tumors is one of the key steps to give right pathological diagnosis and clinical therapy.

Key words: Carcinoma, acinar cell, Parotid gland, Neoplasm metastasis, Cavernous sinus, Immunohistochemistry, Pathology

摘要： 目的 探讨左侧海绵窦转移性腮腺腺泡细胞癌的临床病理学特征。方法 报告1 例临床罕见的左侧海绵窦转移性腮腺腺泡细胞癌患者的临床经过，分析其临床表现、病理学特点和鉴别诊断要点，并复习相关文献。结果 女性患者，50 岁。临床表现为左眼视物模糊、阵发性头晕。MRI 显示左侧鞍旁海绵窦区占位性病变。术中可见左侧海绵窦上壁灰红色肿瘤组织，质地柔软，血供丰富。组织形态学观察肿瘤组织由体积较大的细胞构成，胞质嗜酸性，呈片状、腺泡状或乳头状排列，胞核为圆形或卵圆形，可见小核仁；免疫组织化学染色肿瘤细胞表达细胞角蛋白、上皮膜抗原、波形蛋白、S-100 蛋白，胶质纤维酸性蛋白表达呈弱阳性，灶性表达P53 蛋白，Ki-67 抗原标记指数为5% ~ 10%，不表达神经内分泌和垂体激素标志物。根据患者既往腮腺肿瘤切除术史，并对比腮腺肿瘤与海绵窦肿瘤的组织形态学及免疫表型，最终明确诊断为海绵窦转移性腮腺腺泡细胞癌，随访21 个月无复发。结论 海绵窦转移性腮腺腺泡细胞癌来自腮腺，临床十分罕见，诊断过程中应详细了解病史，并注意与组织形态学及免疫表型与之相重叠的乳头状型脑膜瘤、脉络丛乳头状肿瘤、乳头状型室管膜瘤、乳头状型胶质神经元肿瘤及脊索瘤等相鉴别，以免误诊或漏诊。

关键词: 癌, 腺泡细胞, 腮腺, 肿瘤转移, 海绵窦, 免疫组织化学, 病理学