内淋巴囊肿瘤临床病理分析及文献复习

Endolymphatic sac tumor: Clinicopathological features and review of literature

目的 :探讨1例内淋巴囊肿瘤(endolymphatic sac tumor, ELST)患者的临床表现、病理学特点及其鉴别诊断,以提高对该罕见肿瘤的认识。方法:观察1例ELST患者的病理学特征和免疫表型,并复习相关文献。结果:ELST呈乳头状、腺样排列,表面被覆单层柱状上皮细胞,细胞无异型性,细胞质丰富、透明,间质为大量增生的纤维结缔组织。免疫组织化学(免疫组化)检测结果显示,ELST组织中AE1/AE3、上皮膜抗原(epithelial membrane antigen,EMA)、波形蛋白均呈弥漫阳性;胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)、S-100均呈局灶阳性,细胞增殖指数Ki-67约为1%;突触素(synaptophysin, Syn)、嗜铬粒蛋白A (chromograninA, CgA)、神经元特异性烯醇化酶、甲状腺转录因子(thyroid transcription factor-1,TTF-1)、甲状腺球蛋白则均为阴性。结论:ELST罕见,患者缺少特征性的临床表现,确诊需要依靠石蜡组织形态学观察和免疫组化检测,目前该病较为肯定的治疗方法是外科手术完整切除。

Objective: To study the clinnicopathological features and differential diagnosis of endolymphatic sac tumorfor improving the understanding of this rare tumor. Methods: Tumor specimen from a case of endolymphatic sac tumor was observed under light microscope. Immunohistochemistry examination was performed and relevant literatures were reviewed. Results: Histopathologic examination presented a papillary-glandular pattern, and was covered by a single layer columnar epithelium cells containing clear cytoplasm. There were minimal cellular atypia. The stroma was rich in large number of proliferative fibrous connective tissue. Immunohistochemically,the tumor cells were diffusely positive for AE1/AE3, EMA, vimentin, focally positive for GFAP, S-100, andnegative for Syn, CgA, NSE, TTF-1, TG. The proliferating index Ki-67 was about 1%. Conclusions: Endolymphatic sac tumor is rare, and lacks specific clinical manifestations. The pathological diagnosis depends on morphologic characteristics in paraffin-embedded tissue section and immunohistochemical staining. Whole intact tumor resection is the most effective treatment ofendolymphatic sac tumor.