Oyama K, Embi C, Rader A E
Department of Pathology, Oregon Health Sciences University, Portland, Oregon 97201-3098, USA.
Diagn Cytopathol. 2000 Jun;22(6):376-8. doi: 10.1002/(sici)1097-0339(200006)22:6<376::aid-dc9>3.0.co;2-6.
Retrorectal cysts are uncommon lesions of uncertain histogenesis, and primary carcinoid tumors arising in retrorectal cysts are extremely rare. We present the case of a 52-yr-old man who had a 22-cm partially cystic, partially solid mass in the presacral space. A computed tomography-guided fine-needle aspiration of the mass was performed. The smears contained abundant keratinous debris and rare groups of tumor cells. The tumor cells were cuboidal, with slightly granular cytoplasm and centrally located nuclei with speckled chromatin and inconspicuous nucleoli. Immunocytochemical analysis revealed strong reactivity for chromogranin and keratin, and focal reactivity for synaptophysin and neuron-specific enolase. The cytological diagnosis of a carcinoid arising in a tail-gut cyst was confirmed histologically. This is the first reported case of a carcinoid arising in a retrorectal cyst diagnosed preoperatively by cytology. This diagnosis is possible in the setting of consistent clinical, radiographic, and cytological findings.
直肠后囊肿是一种组织发生不明的罕见病变，起源于直肠后囊肿的原发性类癌肿瘤极为罕见。我们报告一例52岁男性患者，其骶前间隙有一个22厘米的部分囊性、部分实性肿块。对该肿块进行了计算机断层扫描引导下的细针穿刺抽吸。涂片含有丰富的角质碎片和罕见的肿瘤细胞群。肿瘤细胞呈立方形，胞质略呈颗粒状，细胞核位于中央，染色质呈斑点状，核仁不明显。免疫细胞化学分析显示嗜铬粒蛋白和角蛋白呈强反应性，突触素和神经元特异性烯醇化酶呈局灶性反应性。组织学证实了尾肠囊肿中类癌的细胞学诊断。这是首例术前通过细胞学诊断的直肠后囊肿中类癌病例。在临床、影像学和细胞学表现一致的情况下，这种诊断是可能的。
