Evaluation for concomitant thyroid nodules and primary hyperparathyroidism in patients undergoing parathyroidectomy or thyroidectomy

Surgeon-driven thyroid interrogation of patients presenting with primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism (pHPT) is an increasingly prevalent disease affecting all age groups. The authors sought to determine the impact of a "thyroid interrogation" practice protocol on the surgical treatment of patients with the diagnosis of pHPT referred to a single surgeon.

STUDY DESIGN

We performed a retrospective review of prospectively gathered data on parathyroidectomy (PTX) patients undergoing both a prospective clinical thyroid evaluation and thyroid ultrasound between January 2008 and October 2012.

RESULTS

Only 5.6% of 468 PTX patients were referred to a single surgeon for both parathyroid and thyroid surgical evaluation; 31% of patients had known pre-existing thyroid disease (hypothyroidism most commonly), and 22% of patients had palpable thyroid abnormalities unrecognized in 67% of cases by the referring physician. Of the 468 patients, 2.6% had a history of classic head and neck radiation exposure, 2.6% a history of radio-iodine treatment, and 3% a family history of thyroid cancer. Thyroid abnormalities were found on ultrasound in 61% of patients, and 26% of patients underwent thyroid biopsies. Parathyroid and thyroid surgery was combined for 18.4% of patients; indications included obstructive symptoms (3.2%), hyperthyroidism (0.9%), intraoperative findings (5.1%), and concern for malignancy (9.2%). Malignancy was diagnosed in 23 patients (4.9%), only 8 of whom had been referred for thyroid evaluation.

CONCLUSIONS

The majority of patients referred for PTX had evidence of thyroid pathology. For an important minority of these patients, benign and malignant disease was identified that merited surgical treatment at the time of PTX. We recommend comprehensive thyroid evaluation of patients referred for PTX.

Clinical review: Parathyroid localization and implications for clinical management

CLINICAL CONTEXT

The prevalence of hyperparathyroidism, especially primary hyperparathyroidism, has increased in recent decades due to improvements in diagnostic techniques with a corresponding surge in parathyroid surgery, leading to the development of focused, minimally invasive surgical approaches. Focused parathyroidectomy is predicated on preoperative localization of suspected parathyroid pathology. As a result, there has been a proliferation of parathyroid imaging modalities and protocols, resulting in confusion about their indications and applications.

EVIDENCE ACQUISITION

Bibliographies from clinical trials and review articles published since 2000 were reviewed and supplemented with targeted searches using biomedical databases. We also employed our extensive clinical experience.

EVIDENCE SYNTHESIS

The best-studied modalities for parathyroid localization are nuclear scintigraphy and sonography and are widely applied as initial studies. Multiple variations exist, and several additional noninvasive imaging techniques, such as computed tomography and magnetic resonance, are described. The exquisite anatomical detail of 4-dimensional computed tomography must be balanced with significant radiation exposure to the thyroid gland. Invasive venous PTH sampling and parathyroid arteriography have important roles in remedial cases. Due to considerable heterogeneity in imaging, multidisciplinary collaboration between endocrinologists, surgeons, and radiologists is beneficial.

CONCLUSIONS

Parathyroid localization is indicated in surgical candidates. Crucial considerations when selecting an imaging study include availability, cost, radiation exposure, local expertise, and accuracy. Additional factors include the patient's anticipated pathology and whether it is de novo or refractory disease. An approach to imaging for patients with primary hyperparathyroidism is presented.

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.

Coexistence of parathyroid adenoma and papillary thyroid carcinoma

Purpose

Although several reports have been published regarding the coexistence of hyperparathyroidism and papillary thyroid carcinomas, concurrence of parathyroid adenoma and papillary thyroid carcinoma is extremely rare. The aim of this study was to describe experiences with concurrent parathyroid adenoma and papillary thyroid carcinoma.

Methods

Seven patients with concurrent parathyroid adenoma and papillary thyroid carcinoma were identified between January 2006 and December 2007, and their medical records were reviewed retrospectively.

Results

Of the seven patients identified, three were male and four were female; their mean age was 53.6 years. None of the patients presented with symptomatic hyperparathyroidism preoperatively. On laboratory findings, four patients had mild to moderate hypercalcemia, but serum parathyroid hormone concentrations were high in all patients. Preoperative imaging showed suspicious features of diseased parathyroid glands in four patients; two upon ultrasonography and computed tomography together and two upon ultrasonography only. The coexistence of parathyroid adenoma did not affect the extent of thyroid surgery. Laboratory values after surgery returned to within normal ranges in all patients.

Conclusion

It is important not only to analyze serum calcium levels but also to carefully interpret imaging studies in order to identify asymptomatic hyperparathyroidism when performing thyroid cancer surgery.

Preoperative thyroid ultrasound is indicated in patients undergoing parathyroidectomy for primary hyperparathyroidism

BACKGROUND

Primary hyperaparathyroidism (pHPT) is often accompanied by underlying thyroid pathology that can confound preoperative parathyroid localization studies and complicate intra-operative decision making. The aim of this study was to examine the utility of preoperative thyroid ultrasonography (US) in patients prior to undergoing parathyroidectomy for pHPT.

METHODS

An Institutional Review Board approved prospective study was undertaken from January 2005 through July 2008. All patients with pHPT meeting inclusion criteria (n=94) underwent preoperative thyroid ultrasound in addition to standard (99m)Tc-sestamibi scintigraphy for parathyroid localization. Demographics, operative management and final pathology were examined in all cases.

RESULTS

Fifty-four of the 94 patients (57%) were noted to have a thyroid nodule on preoperative US, of which 30 (56%) underwent further examination with fine needle aspiration biopsy. Alteration of the operative plan attributable to underlying thyroid pathology occurred in 16 patients (17%), with patients undergoing either total thyroidectomy (n=9) or thyroid lobectomy (n=7). Thyroid cancer was noted in 33% of patients undergoing thyroid resection, and 6% of all patients with HPT.

CONCLUSIONS

The routine utilization of preoperative thyroid ultrasound in patients prior to undergoing parathyroid surgery for pHPT is indicated. The added information from this non-invasive modality facilitates timely management of co-incidental, and sometimes malignant, thyroid pathology.

Impact of thyroid nodular disease on 99mTc-sestamibi scintigraphy in patients with primary hyperparathyroidism

BACKGROUND

Primary hyperparathyroidism with coexisting thyroid nodular disease (TND) has been considered a contraindication for selective parathyroidectomy because the low sensitivity of preoperative localization studies, especially 99(m)Tc-sestamibi scanning (MIBI) and ultrasound. The aim of this study was to assess the impact of concomitant TND in the preoperative image studies.

METHODS

A total of 236 consecutive patients who had parathyroidectomy for sporadic hyperparathyroidism and the preoperative localization study that was done with MIBI were reviewed. Patients were divided into three groups: those who did not have any thyroid disease, those who had concomitant TND not necessary to resect, and those in whom thyroid resection due to TND was necessary at the time of parathyroidectomy.

RESULTS

MIBI showed a sensitivity of 78.5% in patients without concomitant TND, 73% in patients with TND but not thyroidectomy needed, and 54.5% in the cases that thyroid resection was necessary. When MIBI and ultrasound were both suspicious for an adenoma, the sensitivity was not influenced by the TND.

CONCLUSION

In patients with coexisting thyroid disease but not thyroidectomy needed, MIBI scintigraphy contributes to the detection of a solitary adenoma. When thyroid resection is required, MIBI imaging is often negative.