Enlarged parathyroid glands discovered in normocalcemic patients during thyroid surgery

The American Association of Endocrine Surgeons Guidelines for the Definitive Surgical Management of Thyroid Disease in Adults

OBJECTIVE

To develop evidence-based recommendations for safe, effective, and appropriate thyroidectomy.

BACKGROUND

Surgical management of thyroid disease has evolved considerably over several decades leading to variability in rendered care. Over 100,000 thyroid operations are performed annually in the US.

METHODS

The medical literature from 1/1/1985 to 11/9/2018 was reviewed by a panel of 19 experts in thyroid disorders representing multiple disciplines. The authors used the best available evidence to construct surgical management recommendations. Levels of evidence were determined using the American College of Physicians grading system, and management recommendations were discussed to consensus. Members of the American Association of Endocrine Surgeons reviewed and commented on preliminary drafts of the content.

RESULTS

These clinical guidelines analyze the indications for thyroidectomy as well as its definitions, technique, morbidity, and outcomes. Specific topics include Pathogenesis and Epidemiology, Initial Evaluation, Imaging, Fine Needle Aspiration Biopsy Diagnosis, Molecular Testing, Indications, Extent and Outcomes of Surgery, Preoperative Care, Initial Thyroidectomy, Perioperative Tissue Diagnosis, Nodal Dissection, Concurrent Parathyroidectomy, Hyperthyroid Conditions, Goiter, Adjuncts and Approaches to Thyroidectomy, Laryngology, Familial Thyroid Cancer, Postoperative Care and Complications, Cancer Management, and Reoperation.

CONCLUSIONS

Evidence-based guidelines were created to assist clinicians in the optimal surgical management of thyroid disease.

The prevalence and anatomy of parathyroid glands: a meta-analysis with implications for parathyroid surgery

Purpose

The anatomy of parathyroid glands (PTG) is highly variable in the population. The aim of this study was to conduct a systematic analysis on the prevalence and location of PTG in healthy and hyperparathyroidism (HPT) patients.

Methods

An extensive search of the major electronic databases was conducted to identify all studies that reported relevant data on the number of PTG per patient and location of PTG. The data was extracted from the eligible studies and pooled into a meta-analysis.

Results

The overall analysis of 26 studies (n = 7005 patients; n = 23,519 PTG) on the number of PTG showed that 81.4% (95% CI 65.4–85.8) of patients have four PTG. A total of 15.9% of PTG are present in ectopic locations, with 11.6% (95% CI 5.1–19.1) in the neck and 4.3% (95% CI 0.7–9.9) in mediastinum. The subgroup analysis of ectopic PTG showed that 51.7% of ectopic PTG in the neck are localized in retroesophageal/paraesophageal space or in the thyroid gland. No significant differences were observed between the healthy and HPT patients and cadaveric and intraoperative studies.

Conclusions

Knowledge regarding the prevalence, location, and anatomy of PTG is essential for surgeons planning for and carrying out parathyroidectomies, as any unidentified PTG, either supernumerary or in ectopic location, can result in unsuccessful treatment and need for reoperation.

Electronic supplementary material

The online version of this article (10.1007/s00423-019-01751-8) contains supplementary material, which is available to authorized users.

MULTIGLANDULAR PARATHYROID GLAND DISEASE: AN INCIDENTAL DISCOVERY IN NORMOCALCEMIC PATIENTS DURING THYROID SURGERY

Context

Several enlarged parathyroid glands could be found during thyroid surgery in normocalcemic patients without evidence of primary or secondary hyperparathyroidism, indicating multiglandular parathyroid gland disease (MGD).

Objective

Clinical role of various levels of serum ionized calcium (Ca²⁺) in patients diagnosed with incidental MGD during thyroid surgery remains controversial. The aim of the study was to evaluate the features of PHPT and the clinical role of serum Ca²⁺ in normocalcemic patients diagnosed with incidental MGD.

Study design

A prospective study of patients with normal preoperative Ca²⁺ to be operated on for thyroid diseases in 2010-2013 and diagnosed with MGD during thyroid surgery.

Methods

An analysis of clinical data from 3,561 patients to be surgically treated for thyroid diseases revealed 219 (6%) patients with MGD and normal serum Ca²⁺. Further data analyses showed patients with MGD and high normal (≥1.25 - 1.3 mmol/L) serum Ca²⁺ (n = 89) and with moderate-low (1.0 - 1.24 mmol/L) serum Ca²⁺ (n = 130).

Results

Primary hyperparathyroidism was diagnosed intra- and post-operatively in 48 (54%) patients with high-normal serum Ca²⁺ and in 2 (2%) patients with moderate-low serum Ca²⁺ (p<0.0001). Parathyroid hormone, serum Ca²⁺ as well as urine calcium excretion were elevated in 2 (2%) patients with moderate-low serum Ca²⁺ and in 18 (20%) patients with high-normal Ca²⁺ at follow-up (p<0.0001).

Conclusion

Serum Ca²⁺ level within the normal range, but higher than 1.25 mmol/L (high-normal) is associated with primary hyperparathyroidism, which should be considered in patients with visually diagnosed MGD, but without clinical symptoms of hyperparathyroidism.

Surgical treatment of concomitant thyroid and parathyroid disorders: analysis of 4882 cases

The thyroid gland disease incidence in hyperparathyroidism (HPT) is higher than the incidence of thyroid disease in general population. Likewise, HPT is more frequent in patients primary admitted due to thyroid disease, than in general population. The aim of this study was to determine the incidence and clinical characteristics of concomitant HPT and thyroid disease, based on a single center experience. From 2009 to 2014, a total of 4882 patients underwent thyroidectomy and/or parathyroidectomy at the Center for Endocrine Surgery, Belgrade. We reviewed the database to find out indications for surgery, clinical characteristics, operative and histopathological findings. Out of 4033 patients, who underwent thyroidectomy, in 114 cases (2.8 %) parathyroidectomy was simultaneously performed. Out of these 114 patients, 42 patients (37 %) had normocalcemic HPT. Among 849 patients primary operated due to HPT, thyroid gland disease that required surgery was found in 224 (26.4 %). In patients primary seen for HPT, thyroid cancer was found in 22 (9.8 %), Hashimoto's thyroiditis in 41 (18.3 %) and micropapillary carcinoma in 36 cases (16.1 %). Due to residual or recidivant HPT, 16 patients (15 who primary underwent parathyroidectomy and 1 primary seen for thyroid disease) needed a reoperation. There are a considerable number of patients with concomitant thyroid and parathyroid disease; this justifies the routine analyses of calcemia and PTH level in patients preparing for thyroidectomy, and sets up the ground for the thyroid investigations in HPT.

Parathyroid incidentaloma

Incidentalomas are lesions which are asymptomatic and detected incidently during imaging or surgery. Parathyroid incidentalomas are a rare entity. Enlargement of gland without hyperfunction may be an early stage of disease. Symptomatology is usually non-specific or related to renal and skeletal system. Total serum calcium estimation may be used as a screening modality. Sestamibi scan is a more accurate imaging technique than USG. FNAB - PTH measurement is the most reliable minimally invasive nonsurgical test for parathyroid tissue verification. Incidently discovered enlarged parathyroid gland may be removed to avoid a re-do surgery.

Parathyroid incidentalomas detected during thyroid ultrasonography and effect of chronic thyroiditis on false positive parathyroid lesions

We aimed to determine the prevalence of parathyroid incidentalomas in patients referred for thyroid ultrasonography (US) and investigate the role of chronic thyroiditis on false positive lesions. Patients suspected to have parathyroid lesions during thyroid US were recorded prospectively between August 2009 and January 2010. Patients referred for parathyroid US and patients with known high serum calcium or parathyroid hormone (PTH) levels were excluded. Suspected parathyroid lesions were defined as hypoechoic, homogeneous, solid lesions with regular margins located outside the thyroid lobe, most commonly inferior to the thyroid gland. Thyroid US was performed in 6,528 patients. There were 78 patients (1.19 %) (73 female and 5 male) with suspected parathyroid lesion. The diagnosis of a true parathyroid adenoma was confirmed in 6 (7.69 %) patients. In patients with true adenoma, mean serum calcium, phosphorus, and PTH levels were 10.57 ± 0.48 mg/dl, 3.03 ± 0.52 mg/dl, and 182.91 ± 46.62 pg/ml, respectively. Among 72 patients with false positive parathyroid lesion, antithyroid peroxidase antibody was positive in 50 (69.4 %), antithyroglobulin antibody was positive in 46 (63.9 %), and one of these antibodies were positive in 59 (81.9 %) patients. Also, 46 (63.9 %) of these patients had thyroid dysfunctions (43 hypothyroidism and 3 hyperthyroidism) and 59 (81.9 %) had chronic thyroiditis ultrasonographically. Parathyroid incidentaloma was detected in 0.09 % of patients referred for thyroid US. The presence of clinically or ultrasonographically chronic thyroiditis might cause inadvertent interpretation of a hypoechoic lesion as a parathyroid pathology during thyroid US.

Association of parathyroid pathology with well-differentiated thyroid carcinoma

OBJECTIVE

The objective was to evaluate the association of well-differentiated thyroid carcinoma and parathyroid pathology.

METHODS

The medical records of 14 patients with concomitant pathologies were retrospectively reviewed.

RESULTS

Parathyroidectomies (1.3%) and thyroidectomies (3.5%) performed for well-differentiated thyroid carcinoma resulted in the diagnosis of concomitant pathologies. Five patients had a primary hyperparathyroidism (PHPT) and nine were operated for thyroidectomy with intraoperative finding of an enlarged parathyroid gland. Patients (64%) were normocalcemic preoperatively. Thirteen had papillary carcinoma. Fifty percent of patients had multiple foci of papillary microcarcinoma. Twenty-nine percent of patients had parathyroid hyperplasia. All patients with preoperative hypercalcemia normalized their serum calcium. During follow-up, thyroglobuline, calcium serum values and cervical ultrasound showed no evidence of recurrence of the diseases.

CONCLUSIONS

These observations stress the importance of pre and intraoperative evaluation to detect overt thyroid and parathyroid pathology before performing a parathyroidectomy for hyperparathyroidism or a thyroidectomy for a well-differentiated thyroid carcinoma.

Incidental Parathyroid Disease during Thyroid Surgery: Should We Remove Them?

Aim. Despite an incidence of parathyroid "incidentalomas" of 0.2%-4.5%, only approximately 135 cases have been reported in the literature. We present eight patients in whom an incidental abnormal parathyroid gland was found during routine thyroid surgery. We have reviewed the literature and postulate whether these glands could represent further evidence of a preclinical stage of primary hyperparathyroidism. Methods. A retrospective analysis of all 236 thyroid operations performed by a single surgeon was performed to identify patients in whom abnormal parathyroid tissue was removed at surgery. Results. 8/236 patients (3.39%) had a single macroscopically abnormal parathyroid gland removed and sent for analysis. Seven patients were found to have histological evidence of a parathyroid adenoma or hyperplasia. None of the patients had abnormal serum calcium detected preoperatively. Postoperatively, four patients had normal calcium, three had temporary hypocalcaemia and one refused followup. No patients had recurrent laryngeal nerve impairment. Conclusions. Despite the risk of removing a histologically normal gland, we believe that when parathyroid "incidentalomas" are found during surgery they should be excised and sent for histological analysis. We have found this to be a safe procedure with minimal morbidity to the patient. As the natural history of primary hyperparathyroidism is better understood, these glands found in normocalcaemic patients may in fact represent the early or preclinical phase of the disease. By removing them at the original operation, the patient is saved redo neck surgery with its high complication rate as or when clinically apparent primary hyperparthryoidism develops in the future.

Parathyroid incidentaloma. Literature review about three case reports

BACKGROUND

Parathyroid incidentaloma is not a well-known entity. The aim of this study was to show its incidence and to discuss its management.

METHODS

This was a prospective study analyzing cases of enlarged parathyroid glands discovered during thyroid surgery. The records of patients with parathyroid incidentaloma were reviewed. We also reviewed all cases of primary hyperparathyroidism (HPTPs) operated during the same period for comparison.

RESULTS

Three cases of enlarged parathyroid were found. No clinical or biochemical features led us to suspect hyperparathyroidism before surgery, but a macroscopically enlarged parathyroid gland was discovered during the dissection and was removed in all three patients.

CONCLUSIONS

Enlarged parathyroid glands discovered at the time of surgery may represent an early pathological stage responsible for overt primary hyperparathyroidism. In absence of major risk for recurrent nerve palsy, we recommend removal of any enlarged parathyroid discovered during neck surgery in order to avoid the risks of future surgical procedures, preserving in the same time at least one normal parathyroid gland.

Does multiple gland disease in primary hyperparathyroidism correlate with age or sex?

PURPOSE

Paediatric primary hyperparathyroidism (PHPT) patients suffer more often from multiple gland disease (MGD) than adults. The question occurs whether MGD in adult PHPT patients also correlates with age or sex and whether familial PHPT plays a decisive role. This is significant, as it would influence our decision for a focused approach or the bilateral cervical exploration.

MATERIALS AND METHODS

We retrospectively analysed 465 consecutive PHPT patients who underwent surgery in our department between September 2001 and December 2008.

RESULTS

PHPT patients aged 40 years or younger suffered significantly more often from MGD than older patients (22.9% versus 11.0%). If familial PHPT disorders, which were more common in young patients, were excluded, the divergence between these two groups vanished (12.5% versus 10.0%). There was no statistical significant difference in the frequency of MGD between men (12.2%) and women (12.3%).

CONCLUSIONS

If familial PHPT can be ruled out, the frequency of MGD in adult PHPT patients does not correlate with age or with sex. Therefore, age and sex do not imply specific surgical approaches in adult PHPT patients.