Outcome of large noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP).

Outcome of large noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP).

Thyroid. 2017 Jan 30;:

Authors: Xu B, Tallini G, Scognamiglio T, Roman BR, Tuttle RM, Ghossein R

Abstract
BACKGROUND: In 2016, encapsulated papillary thyroid carcinoma, follicular variant 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.
METHODS: The pathology database 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 2 years of clinical follow up (FU), and 49 (62%) had ≥ 4 years of FU. The clinicopathologic characteristics were reviewed and documented by four endocrine pathologists.
RESULTS: The median size of the NIFTP was 4.5 cm (range 4.0 - 8.0). 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 cm 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 all patients including all cases (n = 25) with nodal tissue available for microscopic examination .Twenty-six (33%) underwent thyroid lobectomy alone, and 37 (47%) did not receive radioactive iodine (RAI) ablation. No recurrence was observed in the entire cohort including all 32 patients with ≥ 2 years of FU who did not receive RAI therapy (median FU: 6.7 years). Among patients with ≥ 4 years of FU, all 25 individuals without RAI therapy did not recur with a median FU of 11.2 years. Patients with larger tumor size tended to receive postoperative RAI ablation (p =0.001).
CONCLUSION: 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.

PMID: 28136139 [PubMed - as supplied by publisher]

http://ift.tt/2kQCMvV


http://ift.tt/2kgeVFX