Xu Bin, Tallini Giovanni, Scognamiglio Theresa, Roman Benjamin R, Tuttle R Michael, Ghossein Ronald A
1 Department of Pathology, Sunnybrook Health Sciences Centre , Toronto, Canada .
2 Department of Pathology, Bologna University School of Medicine , Bologna, Italy .
Thyroid. 2017 Apr;27(4):512-517. doi: 10.1089/thy.2016.0649. Epub 2017 Feb 24.
In 2016, encapsulated follicular variant of papillary thyroid carcinoma without invasion was renamed "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) in order to reduce overtreatment of this indolent tumor. However, many endocrinologists remain uneasy about managing large (≥4 cm) NIFTP conservatively without radioactive iodine (RAI) therapy. The objectives of this study are to characterize the clinicopathologic characteristics and outcome of large NIFTP in order to assist therapeutic decision making.
The pathology databases of four tertiary hospitals were searched for large (≥4 cm) NIFTP. Cases with separate foci of carcinoma were excluded. Seventy-nine cases fulfilled the inclusion criteria. Among them, 56 (71%) had at least two years of clinical follow-up (FU), and 49 (62%) had four or more years of FU. The clinicopathologic characteristics were reviewed and documented by four endocrine pathologists.
The median size of the NIFTP was 4.5 cm (range 4.0-8.0 cm). The entire capsule was sampled in 50 (63%) tumors, while in the remaining 29 (37%) cases, it was submitted representatively, with a median of 2.1 blocks per centimeter of tumor examined. Large NIFTP had a female preponderance with a male:female ratio of 1:1.8, and presented at a median age of 49 years. There were no lymph node metastases at diagnosis in any of the patients, and none of the patients (n = 25) in whom nodal tissue was available for microscopic examination had positive findings. Twenty-six (33%) underwent thyroid lobectomy alone, and 37 (47%) did not receive RAI ablation. No recurrence was observed in the entire cohort, including all 32 patients with two or more years of FU who did not receive RAI therapy (median FU: 6.7 years). Among patients with four or more years of FU, all 25 individuals without RAI therapy did not recur, with a median FU of 11.2 years. Patients with a larger tumor size tended to receive postoperative RAI ablation (p = 0.001).
Similar to their small counterparts, large NIFTP appear to have an extremely low risk of recurrence (zero in this cohort), even when treated conservatively without RAI therapy. Surgical treatment alone, including lobectomy, appears to be adequate for large NIFTP.
2016年，无侵袭性的甲状腺乳头状癌滤泡型被重新命名为“具有乳头状核特征的非侵袭性滤泡性甲状腺肿瘤”（NIFTP），以减少对这种惰性肿瘤的过度治疗。然而，许多内分泌科医生对于不采用放射性碘（RAI）治疗而保守处理较大（≥4 cm）的NIFTP仍感到不安。本研究的目的是描述较大NIFTP的临床病理特征及预后，以辅助治疗决策。
在四家三级医院的病理数据库中搜索较大（≥4 cm）的NIFTP。排除有癌灶分离的病例。79例符合纳入标准。其中，56例（71%）有至少两年的临床随访（FU），49例（62%）有四年或更长时间的FU。四名内分泌病理学家对临床病理特征进行了回顾并记录。
NIFTP的中位大小为4.5 cm（范围4.0 - 8.0 cm）。50例（63%）肿瘤的整个包膜均被取材，其余29例（37%）则进行代表性取材，每厘米肿瘤检查的中位组织块数为2.1块。较大的NIFTP以女性居多，男女比例为1:1.8，中位发病年龄为49岁。所有患者在诊断时均无淋巴结转移，在可进行显微镜检查的淋巴结组织的25例患者中，均未发现阳性结果。26例（33%）仅接受了甲状腺叶切除术，37例（47%）未接受RAI消融。整个队列中均未观察到复发，包括所有32例未接受RAI治疗且有两年或更长时间FU的患者（中位FU：6.7年）。在有四年或更长时间FU的患者中，所有25例未接受RAI治疗的患者均未复发，中位FU为11.2年。肿瘤较大的患者倾向于接受术后RAI消融（p = 0.001）。
与较小的NIFTP相似，较大的NIFTP似乎复发风险极低（本队列中为零），即使不采用RAI治疗而进行保守治疗。单独的手术治疗，包括叶切除术，似乎对较大的NIFTP就足够了。
