Identification of occult tumors by whole-specimen mapping in solitary papillary thyroid carcinoma

Abstract

We undertook this study to estimate an accurate incidence and spread patterns of occult papillary thyroid carcinoma (PTC) in patients with a preoperative diagnosis of solitary PTC by using whole-specimen mapping of all specimens after a total thyroidectomy. Enrolled prospectively in this whole-thyroid mapping study are 82 consecutive patients who underwent a total thyroidectomy under a preoperative diagnosis of solitary PTC. All thyroidectomy specimens were serially sectioned in 2 mm thickness and whole-thyroid mapping was carried out for additional foci of occult PTC. The frequencies of occult lesions detected in the whole and contralateral lobe were determined, and clinicopathologic factors associated with multifocality were assessed. Whole-thyroid mapping revealed 66 occult PTC lesions missed by preoperative ultrasound in 37 (45.1%) of the 82 patients. The great majority (92.5%) of the occult PTC was smaller than 3 mm in size and 25 patients (30.5%) had contralateral lesions. We found that the male sex was an independent predictor of multifocality (odds ratio (OR), 3.00; 95% CI, 1.11-8.14), adjusting for preoperative findings. Analysis with pathologic parameters showed that the male sex (OR, 5.03; 95% CI, 1.68-15.08) and extrathyroidal extensions (OR, 3.03; 95% CI,) were associated with multifocal PTC. However, none of the clinicopathologic factors evaluated predicted contralateral PTC. Our study demonstrates the diagnostic limitations of ultrasound for the detection of multifocal PTC and the need to consider the possibility of occult lesions in the management of solitary PTC, especially in male patients.

Prevalence and predictor for malignancy of contralateral thyroid nodules in patients with unilateral PTMC: a systematic review and meta-analysis

“…Feng et al demonstrated that tumor > 1 cm was an independent predictor of contralateral carcinoma ( 32 ). In contrast, Park et al suggested that the size of the primary tumor could not be a predictor for contralateral carcinoma ( 33 ). Meanwhile, in a study that followed 992 patients with benign thyroid nodules for 5 years, Durant et al reported an increase in diameter for at least 2 mm in 15.4% of the nodules ( 34 ).…”

A comparative study of short-term efficacy and safety for thyroid micropapillary carcinoma patients after microwave ablation or surgery

“…The main reason is that region VI is a blind area for US [38]. Second, five patients in the surgical group had multifocal disease according to the final pathology, which showed small (1-2 mm) and occult (<2 mm) carcinomas that could easily be missed by US [39]. Thus, the conventional examinations (US, FNAC) could not evaluate a solitary tumor with great validity.…”

Risk Factors for Contralateral Occult Papillary Thyroid Carcinoma in Patients with Clinical Unilateral Papillary Thyroid Carcinoma: A Case-Control Study

“…According to the 2015 ATA guidelines, for tumors lesser than 4 cm, confined to one lobe, absent of extrathyroidal extension (ETE), and clinical lymph nodes metastasis (LNM), the extent of surgery was recommended as either lobectomy or total thyroidectomy (TT) [11], depending on the intentionality from patients and surgery team. However, some scholars argued that total thyroidectomy has the advantage of allowing individualized postoperative risk stratification and surveillance [12], and some other previous studies have reported that in patients with unilateral thyroid cancer who underwent total thyroidectomy, contralateral malignant tumors, defined as occult thyroid carcinoma, also represented a nonnegligible proportion [13][14][15][16][17]. Furthermore, evidence indicates that multifocality, including occult contralateral or bilateral thyroid cancer, is an independent risk predictor of recurrence after lobectomy [18].…”