Cases Of NIFTP Research Articles

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features: a single-institutional experience in Japan.

Noninvasive encapsulated follicular variant of papillary thyroid carcinoma (PTC) was reclassified as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). To date, no studies on NIFTP have been reported in Japan. This study aimed to evaluate the clinical, cytological, and pathological findings of 54 cases of NIFTP from a single center in Japan, and compare them with those in the western countries. There were no significant differences in age, sex, or tumor size between patients with NIFTP and those with invasive encapsulated follicular variant -PTC. Ultrasound investigation showed a high suspicion lesion in 6.5% of NIFTP and 44.1% of invasive encapsulated follicular variant -PTC (p<0.001). On fine needle aspiration cytology, 75.7% of NIFTP cases were reported as suspicious for malignancy or malignant. Nuclear grooves and irregular-shaped nuclei were observed in 94.6% of cases of NIFTP. Pathologically, 27.8% cases of NIFTP and 13.0% cases of invasive encapsulated follicular variant -PTC had been originally diagnosed as macrofollicular variants of PTC. There were no NIFTP cases with nodal metastasis. We concluded that NIFTP should be renounced noninvasive encapsulated follicular variant -PTC, and should be considered as a malignant tumor with exceeding indolent behavior, and lobectomy alone should be satisfactory for the diagnosis and treatment.

Noninvasive follicular thyroid neoplasm with papillary-like nuclear features.

Recently, it was proposed that some papillary thyroid carcinomas (PTC) will no longer be termed 'cancer' and are christened as 'noninvasive follicular thyroid neoplasm with papillary-like nuclear features' (NIFTP). As this is a recent definition, little information is available about NIFTP. The objective of this study was to report the frequency, ultrasonographic appearance, cytology result and long-term evolution of cases of NIFTP seen at our institution. We excluded tumours ≤1 cm. The sample consisted of 129 patients. Sixty-four patients were submitted to total thyroidectomy and 65 to lobectomy. These patients with NIFTP did not receive radioiodine. NIFTP corresponded to 15% of cases diagnosed as PTC >1 cm. An ultrasonographic appearance considered to be of low suspicion for malignancy was common in NIFTP (32.5%), whereas a highly suspicious appearance was uncommon (5%). NIFTP frequently exhibited indeterminate cytology (62%), while malignant cytology was uncommon (4%). The patients were followed up for 12-146 months (median 72 months) after surgery. None of the patients developed structural disease during follow-up. Comparing the concentrations of thyroglobulin (Tg) and anti-Tg antibodies (TgAb) obtained 6-12 months after surgery and in the last assessment, none of the patients exhibited an increase in these markers.