Solitary thyroid gland metastasis from rectal cancer: A case report and review of the literature.

BACKGROUND: Metastatic carcinoma of the thyroid gland is a rare encounter in clinical practice, but autopsy series showed that it is not so rare. Thyroid metastasis from colorectal cancer (CRC) is rare and has a poor prognosis. We herein report a rare case of solitary thyroid metastasis from rectal cancer combined with needle tract implantation after fine-needle aspiration (FNA) of the thyroid nodule and review the relevant literature. CASE SUMMARY: A 54-year-old woman with a history of TNM stage III CRC presented a 1.3 cm × 1.0 cm mass in the left thyroid gland. FNA and histological examination of the left thyroid lobe surgical specimen confirmed the diagnosis of isolated metastatic adenocarcinoma from the rectum. Needle tract implantation was observed in the neck 11 mo after the FNA examination. The 2.5-cm seeding lesion was successfully removed by surgery, and the patient recovered well. The literature relevant to this clinical condition, the diagnostic workup, spread pathway, and surgical management of these rare lesions is reviewed. CONCLUSION: For a patient with a thyroid mass and a history of CRC, metastatic thyroid carcinoma should be considered even if the patient has no evidence of other organ metastasis from CRC. FNA cytological examination of the thyroid mass is useful in the differential diagnosis between primary thyroid disease and metastatic thyroid carcinoma. Thyroid lobectomy of the gland containing the metastatic tumor is suggested in patients with metastatic carcinoma of the thyroid.

Fine-Needle Pricking Test of the Parathyroid Gland during Thyroid Surgery in Predicting Parathyroid Function.

Background: Permanent hypoparathyroidism is a serious complication following total thyroidectomy plus central neck dissection (CND). How to evaluate the vascularization of the parathyroid gland in real time is a major concern of thyroid surgeons. This study aimed to evaluate the fine-needle pricking (FNP) test in predicting parathyroid gland function. Methods: The FNP test was performed in patients undergoing total thyroidectomy plus CND between January 1, 2014, and December 31, 2019, to visualize the vascularization of the parathyroid glands. Patients were classified according to the number of parathyroid glands preserved in situ with excellent vascularity (PGPIEV) demonstrated by FNP: group 0 (without PGPIEV), group 1 (with one PGPIEV), group 2 (with two PGPIEV), group 3 (with three PGPIEV), and group 4 (with four PGPIEV). Results: A total of 608 patients with four parathyroid glands underwent FNP testing during thyroidectomy. At least one PGPIEV was demonstrated by FNP testing in 581 patients who had intact parathyroid hormone (iPTH) levels in the normal range after the operation. The prevalence of hypocalcemia decreased from 77.8% in group 0 to 9.8% in group 4 (P < 0.001), and the incidence of hypoparathyroidism decreased from 44.4% in group 0 to 0% in groups 1-4 (P < 0.001). iPTH concentrations on postoperative day 1 were positively correlated with PGPIEV groups (increased from 14.58 ng/l in group 0 to 45.22 ng/l in group 4, P < 0.001). Conclusions: The FNP test is a safe and reliable method to predict parathyroid function. One PGPIEV demonstrated by the FNP test rules out the possibility of patients developing hypoparathyroidism.

The Clinical Significance of Detecting Blood Supply to the Inferior Parathyroid Gland Based on the "Layer of Thymus-Blood Vessel-Inferior Parathyroid Gland" Concept.

Objective: How to preserve the inferior parathyroid gland (IPTG) in situ during central neck dissection (CND) is the major concern of thyroid surgeons. The "layer of thymus-blood vessel-IPTG" (TBP layer) concept showed to be effective in preserving IPTG. The objective of this study was to identify the origin and course of blood supply to IPTG (IPBS) within the TBP layer and to take key points of operation during CND. Design: This is a retrospective control study. Participants. Patients who underwent thyroidectomy plus CND using the TBP layer concept and conventional technique between 2017 and 2019 were enrolled. Measurements. The origin and course of IPBS in relation to recurrent laryngeal nerve (RLN) and thymus and prevalence of hypoparathyroidism were detected. Results: A total of 71.3% of IPTGs (251 of 352) were supplied by ITA branches, defined as type A. Type A was further divided into Types A1 (branches of ITA, coursing laterally to the RLN (53.1%, 187 of 352)) and A2 (branches of ITA, traversing medially to the RLN (18.2%, 64 of 352)). Type A2 was more common on the right side than on the left side (P < 0.001). Fifty-five (15.6%) IPTG feeding vessels originated from the thymus or mediastinum. Nineteen (5.4%) IPTGs were supplied by branches of the superior thyroid artery. The incidence of transient hypoparathyroidism decreased from 45.7% to 3.6% (P < 0.001), in the TBP layer group compared with the conventional technique group. Conclusion: The origin and course of IPBS follow a definite pattern. This mapping and precautions help surgeons optimize intraoperative manipulations for better preservation of IPBS during CND.

Predicting non-small-volume central lymph node metastases (>5 or ≥2 mm) preoperatively in cN0 papillary thyroid microcarcinoma without extrathyroidal extension.

The ability to identify patients with aggressive papillary thyroid microcarcinoma (PTMC) from the low-risk patients is critical to planning proper management of PTMC. Lymph node metastases showed association with recurrence and low survival rate, especially in patients with >5 or ≥2 mm metastatic lymph nodes. Therefore, this study aimed to investigate the preoperatively predictive factors of non-small-volume (metastatic lymph nodes >5 or ≥2 mm in size) central lymph node metastases (NSVCLNM) in PTMC patients. A total of 420 patients with clinically node-negative (cN0) PTMC without extrathyroidal extension underwent thyroidectomy plus central neck dissection (CND) between January 2013 and December 2015, were retrospectively analyzed. Of the 420 patients, 33 (7.9%) had NSVCLNM. The 5-year recurrence-free survival was significantly less in cN0 PTMC patients with NSVCLNM, when compared with patients without NSVCLNM (80.8% vs 100%, P < .001). Multivariate logistic regression revealed age ≤36 years (P < .001), male sex (P = .002), ultrasonic tumor sizes of >0.65 cm (P < .001), and ultrasonic multifocality (P = .039) were independent predictive factors of NSVCLNM. A prediction equation (Y = 1.714 × age + 1.361 × sex + 1.639 × tumor size + 0.842 × multifocality -5.196) was developed, with a sensitivity (69.7%) and a specificity (84.0%), respectively, at an optimal cutoff point of -2.418. In conclusion, if the predictive value was >-2.418 according to the equation, immediate surgery including CND rather than active surveillance might be considered for cN0 PTMC patients.