Division of Head and Neck, Cancer Institute Hospital, 3-8-31 Ariake, Koto-ku, Tokyo, 135-8550, Japan.
World J Surg. 2010 Jun;34(6):1265-73. doi: 10.1007/s00268-009-0305-y.
Poorly differentiated thyroid carcinoma (PDTC) was recognized as an independent clinicohistological entity of thyroid cancer in the 2004 World Health Organization (WHO) classifications, separated from papillary (PTC) and follicular carcinoma (FTC). The Turin proposal provides more specific criteria for the diagnosis of PDTC. However, in an iodine-sufficient country such as Japan, PDTC comprises <1% of all thyroid cancers. In 1983, Sakamoto analyzed pathological characteristics of PTC and FTC that recurred within 5 years after initial surgery and identified solid, trabecular, insular (STI) and scirrhous growth patterns as important predictors of poor prognosis. We re-evaluated the impact of histopathological findings on the clinical course of PTC and FTC.
Specimens from 376 consecutive cases diagnosed as PTC (n = 351) or FTC (n = 25) between 1994 and 2001 were reviewed.
Nine (2%) patients were diagnosed with PDTC according to WHO criteria. Only 1 case (0.3%) met the Turin criteria. In addition, STI components were seen in various specimens as follows: >or=50%, >or=10% but <50%, >0% but <10%, and 0% of specimens for 9 (2%), 31 (8%), 19 (5%), and 317 cases (85%), respectively. As for cause-specific survival, a significant difference was apparent between the >or=50% and >or=10% but <50% groups. Disease-free survival was identical between these groups and was significantly worse than in the >0% but <10% and 0% groups. According to multivariate analysis, histological features of STI >or=10% and squamous metaplasia were significantly related to cause-specific survival, but scirrhous infiltration, necrosis, nuclear atypia, and vascular invasion were not. The presence of STI at a level >or=10% was also a significant risk factor, together with clinical risk factors including large tumor size, large nodal metastasis, and distant metastasis. According to AMES risk-group definition, clinically high-risk patients with STI >or=10% showed the worst 10-year cause-specific survival, at 57%, irrespective of total thyroidectomy with radioactive iodine (RAI) treatment. Ten of 25 PTC patients (40%) with STI >or=10% developed cervical recurrence, whereas 9 of 15 FTC patients (60%) with STI >or=10% showed distant metastasis.
The measurement of STI >or=10% represents a distinctly important risk factor for patient survival. In particular, clinically high-risk patients with STI >or=10% need further therapy beyond RAI. Original histological pattern, as papillary or follicular, affects the site of recurrence.
在 2004 年世界卫生组织（WHO）分类中，低分化甲状腺癌（PDTC）被认为是甲状腺癌的一种独立的临床组织学实体，与乳头状癌（PTC）和滤泡状癌（FTC）分开。都灵提案为 PDTC 的诊断提供了更具体的标准。然而，在像日本这样的碘充足的国家，PDTC 占所有甲状腺癌的比例<1%。1983 年，Sakamoto 分析了初次手术后 5 年内复发的 PTC 和 FTC 的病理特征，发现实性、小梁状、胰岛（STI）和硬化生长模式是预后不良的重要预测因素。我们重新评估了组织病理学发现对 PTC 和 FTC 临床病程的影响。
回顾了 1994 年至 2001 年间连续诊断为 PTC（n=351）或 FTC（n=25）的 376 例患者的标本。
根据 WHO 标准，9 例（2%）患者被诊断为 PDTC。只有 1 例（0.3%）符合都灵标准。此外，在各种标本中均可见 STI 成分，如下所示：≥50%、≥10%但<50%、>0%但<10%和 0%的标本分别为 9（2%）、31（8%）、19（5%）和 317 例（85%）。就特定病因的生存率而言，≥50%和≥10%但<50%组之间存在显著差异。无病生存率在这两组之间是相同的，并且明显差于>0%但<10%和 0%组。通过多变量分析，STI≥10%和鳞状化生的组织学特征与特定病因的生存率显著相关，但硬化浸润、坏死、核异型性和血管侵犯则不然。STI 水平≥10%的存在也是一个显著的危险因素，与包括肿瘤大小大、淋巴结转移大、远处转移在内的临床危险因素一起。根据 AMES 风险组定义，具有 STI≥10%的临床高危患者的 10 年特定病因生存率最差，为 57%，无论是否进行全甲状腺切除术加放射性碘（RAI）治疗。25 例 PTC 患者中有 10 例（40%）STI≥10%发生颈部复发，而 15 例 FTC 患者中有 9 例（60%）STI≥10%发生远处转移。
STI≥10%的测量代表了一个明显重要的生存风险因素。特别是，具有 STI≥10%的临床高危患者需要除 RAI 以外的进一步治疗。原发组织学模式，如乳头状或滤泡状，影响复发部位。
