Sangoi Ankur R, Soslow Robert A, Teng Nelson N, Longacre Teri A
Department of Pathology, Stanford University, Stanford, CA 94305, USA.
Am J Surg Pathol. 2008 Feb;32(2):269-74. doi: 10.1097/PAS.0b013e31814fa9b0.
The differential diagnostic problems usually associated with clear cell carcinoma (CCC) of the ovary have been well characterized and include primitive germ cell tumor, sex cord stromal tumor, and metastasis. Distinction from other types of surface epithelial carcinoma may also pose a diagnostic challenge, but the potential for misdiagnosis of serous tumor of low malignant potential (S-LMP) is not well recognized. We report 13 cases of ovarian CCC with prominent papillary architecture that were initially misdiagnosed as S-LMP or low-grade serous carcinoma either on frozen section or at final diagnosis. The ages of the patients ranged from 39 to 65 years (mean, 52.2 y). All patients presented with a pelvic mass; 1 was undergoing evaluation for infertility. Macroscopically, most were described as unilateral, multilocular cysts with internal papillary structures. On microscopic examination, each tumor had a papillary architecture that accounted for 30% to 95% of the tumor; in 6 cases, the cores of the papillae were hyalinized. The neoplastic cells covering the papillae had clear to granular and eosinophilic cytoplasm. Hobnail cells were focal and often subtle. Most had a low mitotic index (9/13) and/or deceptively bland cytology (8/13); only careful attention to the cytologic features and/or mitotic index allowed correct identification of the tumor type in 5 cases. Six were associated with pelvic/ovarian endometriosis. Ten were Federation of Gynecology and Obstetrics stage I (8 IA, 2 IC), 2 were stage II (1 IIB, 1 IIC), and 1 stage IIIC. CCC with prominent papillary architecture is uncommon, but may pose a challenging differential diagnosis with S-LMP, resulting in inadequate staging and delayed treatment. Features most helpful in distinguishing papillary CCC are unilaterality, nonhierarchical branching, monomorphous cell population, and the presence of more typical CCC patterns elsewhere in the tumor. The presence of endometriosis, although not specific, should also prompt consideration for papillary CCC. Increased numbers of mitotic figures may not be present and high-grade cytologic atypia may be focal, requiring careful examination of multiple tumor sections for detection. As CCC and S-LMP exhibit significantly different immunoreactivity for Wilms' Tumor 1 and estrogen receptor, these markers may also be useful adjunctive tests in problematic cases.
通常与卵巢透明细胞癌（CCC）相关的鉴别诊断问题已得到充分描述，包括原始生殖细胞肿瘤、性索间质肿瘤和转移瘤。与其他类型的表面上皮癌进行鉴别也可能带来诊断挑战，但低恶性潜能浆液性肿瘤（S-LMP）被误诊的可能性尚未得到充分认识。我们报告了13例具有显著乳头结构的卵巢CCC病例，这些病例在冰冻切片或最终诊断时最初被误诊为S-LMP或低级别浆液性癌。患者年龄在39至65岁之间（平均52.2岁）。所有患者均表现为盆腔肿块；1例正在接受不孕症评估。大体上，大多数被描述为单侧、多房囊肿，内部有乳头结构。显微镜检查显示，每个肿瘤都有乳头结构，占肿瘤的30%至95%；6例乳头核心呈玻璃样变。覆盖乳头的肿瘤细胞胞质清晰至颗粒状且嗜酸性。鞋钉样细胞呈局灶性且通常不明显。大多数病例有低有丝分裂指数（9/13）和/或看似温和无异型性（8/13）的细胞学表现；只有仔细关注细胞学特征和/或有丝分裂指数，才在5例中正确识别出肿瘤类型。6例与盆腔/卵巢子宫内膜异位症相关。10例为国际妇产科联盟（FIGO）I期（8例IA期，2例IC期），2例为II期（1例IIB期，1例IIC期），1例为IIIC期。具有显著乳头结构的CCC并不常见，但可能与S-LMP构成具有挑战性的鉴别诊断，导致分期不足和治疗延迟。最有助于鉴别乳头型CCC的特征是单侧性、非分级分支、单一细胞群以及肿瘤其他部位存在更典型的CCC模式。子宫内膜异位症的存在虽然不具有特异性，但也应促使考虑乳头型CCC。可能不存在有丝分裂象数量增加的情况，高级别细胞学异型性可能呈局灶性，需要仔细检查多个肿瘤切片以进行检测。由于CCC和S-LMP对肾母细胞瘤1和雌激素受体表现出显著不同的免疫反应性，这些标志物在疑难病例中也可能是有用的辅助检查。
