ACR Appropriateness Criteria® Parathyroid Adenoma.

Hyperparathyroidism is defined as excessive parathyroid hormone production. The diagnosis is made through biochemical testing, in which imaging has no role. However, imaging is appropriate for preoperative parathyroid gland localization with the intent of surgical cure. Imaging is particularly useful in the setting of primary hyperparathyroidism whereby accurate localization of a single parathyroid adenoma can facilitate minimally invasive parathyroidectomy. Imaging can also be useful to localize ectopic or supernumerary parathyroid glands and detail anatomy, which may impact surgery. This document summarizes the literature and provides imaging recommendations for hyperparathyroidism including primary hyperparathyroidism, recurrent or persistent primary hyperparathyroidism after parathyroid surgery, secondary hyperparathyroidism, and tertiary hyperparathyroidism. Recommendations include ultrasound, CT neck without and with contrast, and nuclear medicine parathyroid scans. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

What is Elective Oncologic Surgery in the Time of COVID-19? A Literature Review of the Impact of Surgical Delays on Outcomes in Patients with Cancer.

BACKGROUND: The impact of the COVID-19 pandemic has spread beyond those infected with SARS-CoV-2. Its widespread consequences have affected cancer patients whose surgeries may be delayed in order to minimize exposure and conserve resources. METHODS: Experts in each surgical oncology subspecialty were selected to perform a review of the relevant literature. Articles were obtained through PubMed searches in each cancer subtype using the following terms: delay to surgery, time to surgery, outcomes, and survival. RESULTS: Delays in surgery > 4 weeks in breast cancer, ductal carcinoma in situ, T1 pancreatic cancer, ovarian cancer, and pediatric osteosarcoma, negatively impacted survival. Studies on hepatocellular cancer, colon cancer, and melanoma (Stage I) demonstrated reduced survival with delays > 3 months. CONCLUSION: Studies have shown that short-term surgical delays can result in negative impacts on patient outcomes in multiple cancer types as well as in situ carcinoma. Conversely, other cancers such as gastric cancer, advanced melanoma and pancreatic cancer, well-differentiated thyroid cancer, and several genitourinary cancers demonstrated no significant outcome differences with surgical delays.

Lobectomy for treatment of differentiated thyroid cancer: can patients avoid postoperative thyroid hormone supplementation and be compliant with the American Thyroid Association guidelines?

BACKGROUND: The American Thyroid Association recommended thyroid lobectomy as an alternative for low-risk differentiated thyroid cancer. One hypothetical benefit includes avoiding lifelong thyroid hormone supplementation; however, guidelines recommend maintaining the thyroid-stimulating hormone <2 mIU/L postoperatively in low-risk patients. Our hypothesis is that most patients will require hormone supplementation to maintain thyroid-stimulating hormone <2 mIU/L, minimizing this advantage of lobectomy. The goal of this study is to determine how often patients have thyroid-stimulating hormone <2 mIU/L after lobectomy without thyroid hormone supplementation. METHODS: A retrospective review of 555 consecutive patients who underwent thyroid lobectomy was performed. Thyroid hormone supplementation was documented, along with thyroid-stimulating hormone levels preoperatively, 7 to 10 days, and 2 to 12 months postoperatively. RESULTS: In the study, 478/555 (86%) patients did not take thyroid hormone before thyroidectomy; 394/478 (82%) had thyroid-stimulating hormone levels available at 7 to 10 days postoperatively, and of these, 218 (55%) had thyroid-stimulating hormone >2 mIU/L. From 2 to 12 months postoperatively, of the 225 patients who continued to remain off thyroid hormone supplementation, 132 (59%) experienced a thyroid-stimulating hormone increase to >2 mIU/L; therefore, 350/478 (73%) patients after thyroid lobectomy had thyroid-stimulating hormone levels >2 mIU/L within a year. CONCLUSION: It is important to counsel patients that to be compliant with the American Thyroid Association guidelines for differentiated thyroid cancer, the majority of patients undergoing thyroid lobectomy may require thyroid hormone supplementation to maintain a thyroid-stimulating hormone level <2 m IU/L.

Impact of vocal cord ultrasonography on endocrine surgery practices.

BACKGROUND: It is common practice to perform flexible laryngoscopy (FL) to ensure true vocal cord (TVC) mobility in patients with previous neck operations or patients with suspected VC dysfunction. Vocal cord ultrasonography (VCUS) is accurate in identifying TVC paralysis. The goal of this study is to evaluate the impact of VCUS as the initial study to confirm TVC mobility in patients requiring preoperative FL. METHODS: A total of 194 consecutive patients with indications for preoperative FL underwent VCUS. In group 1, 52 patients had FL regardless of the results of VCUS, whereas in group 2, 142 patients had VCUS followed by FL only when VCUS was unsatisfactory. RESULTS: VCUS visualized TVC/arytenoids in 164 of 194 (85%) patients. TVC visualization was more common in women (95%) and in patients without thyroid cartilage calcification (92%) (P < .0005). VCUS predicted all paralyzed TVC. In group 2, 76% of patients had adequate VCUS and avoided preoperative FL. Among 24% of patients in whom VCUS was inadequate, 16 had preoperative FL attributable to a lack of TVC visualization, 6 had abnormal TVC mobility, 11 needed additional confirmations, and 2 had previous FL for another reason. CONCLUSION: VCUS changed surgeon practices by avoiding the need for preoperative FL in the majority of patients. This noninvasive and sensitive method demonstrates TVC mobility and safely precludes preoperative FL in most patients.

Feasibility of surgeon-performed transcutaneous vocal cord ultrasonography in identifying vocal cord mobility: A multi-institutional experience.

BACKGROUND: Transcutaneous vocal cord ultrasonography (TVCUS) is a noninvasive study used to identify true vocal cord (TVC) mobility. Its sensitivity in predicting TVC paralysis when compared with indirect flexible laryngoscopy (IFL) ranges from 62 to 93%. This study aimed to evaluate the feasibility of surgeon-performed TVCUS in assessing TVC mobility in the outpatient setting. METHODS: At 5 institutions, 510 consecutive patients underwent 887 TVCUS performed by 8 surgeons during initial surgical evaluation. IFL was obtained in selected patients. TVCUS was repeated during the first postoperative visit, and IFL was obtained only when judged necessary. Clinical parameters were collected and later correlated with TVC visualization. RESULTS: TVC visualization was possible in 688 of 887 TVCUS (77%); visibility ranged from 41 to 86% among performing surgeons. IFL was done in 81 patients (16%) and TVCUS predicted TVC paralysis in all cases when TVC were seen. TVC visualization was possible more often in females than males (83% vs 17%; P < .0005) and in patients without thyroid cartilage calcification than those with calcification (83% vs 42%; P < .0005). CONCLUSION: Experienced surgeon-ultrasonographers can use TVCUS to visualize TVC in most female patients and less so in males. TVCUS is highly sensitive, but operator dependent. This study demonstrates the feasibility of TVCUS and directs further attention to defining its optimal role in assessment of TVC mobility.

Minimizing cost and maximizing success in the preoperative localization strategy for primary hyperparathyroidism.

Ultrasonography of the thyroid, parathyroid, and soft tissues of the neck should always be performed before parathyroidectomy. The most cost-effective localization strategies seem to be ultrasonography followed by four-dimensional computed tomography (4DCT) or ultrasonography followed by sestamibi ± 4DCT. These localization strategies are highly dependent on the quality of imaging. Surgeons should critically evaluate the imaging and operative data at their own institution to determine the best preoperative localization strategy before parathyroidectomy. Surgeons should communicate with the referring physicians about the best localization algorithms in the local area and become the decision maker as to when to obtain them.

Comparison between preconsultation ultrasonography and office surgeon-performed ultrasound in patients with thyroid cancer.

BACKGROUND: Cervical ultrasonography (US) is mandatory before surgery for thyroid cancer and recommended for thyroid nodule evaluation. Therefore, most patients undergo thyroid ultrasound before surgical evaluation. Several US findings are critical for adequate surgical planning but they are often not mentioned on preconsultation US. The goal of this study is to compare the preconsultation US findings with surgeon-performed US (SUS) and describe the changes in management as a consequence of SUS findings in patients with thyroid cancer. METHODS: The charts of 194 consecutive patients with thyroid cancer (2007-2013) from a single institution were reviewed. Preconsultation US and SUS reports were available for 136 patients. Mention of nodes, local invasion, thyroid nodule features/location, and presence of intrathoracic extension was recorded and changes in preoperative and/or operative management based on SUS findings were described. RESULTS: From 136 patients with the diagnosis of thyroid cancer, SUS changed the management of 61 (45 %) patients by identifying preoperatively central and/or lateral node metastasis, indicating preoperative biopsy of suspicious thyroid lesions/nodes, and pointing out thyroid intrathoracic extension. When compared to SUS, the preconsultation US failed to mention node status in 101 (74 %) patients, suspicious nodule features in 60/111 (54 %) patients with suspicious lesions, bilateral thyroid lesions in 19/88 (22 %) patients with bilateral nodules, local invasion in 5/5 (100 %), and intrathoracic extension in 5/5 (100 %) cases. CONCLUSION: Surgeon-performed US changed the operative management of patients with thyroid cancer by demonstrating additional and distinct information compared to preconsultation US in almost half of the patients. Ultrasound is more accurate and critical in the evaluation of patients with thyroid cancer when performed by the surgeon.

American Thyroid Association statement on outpatient thyroidectomy.

BACKGROUND: The primary goals of this interdisciplinary consensus statement are to define the eligibility criteria for outpatient thyroidectomy and to explore preoperative, intraoperative, and postoperative factors that should be considered in order to optimize the safe and efficient performance of ambulatory surgery. SUMMARY: A series of criteria was developed that may represent relative contraindications to outpatient thyroidectomy, and these fell into the following broad categories: clinical, social, and procedural issues. Intraoperative factors that bear consideration are enumerated, and include choice of anesthesia, use of nerve monitoring, hemostasis, management of the parathyroid glands, wound closure, and extubation. Importantly, postoperative factors are described at length, including suggested discharge criteria and recognition of complications, especially bleeding, airway distress, and hypocalcemia. CONCLUSIONS: Outpatient thyroidectomy may be undertaken safely in a carefully selected patient population provided that certain precautionary measures are taken to maximize communication and minimize the likelihood of complications.

Ultrasound elastography in the evaluation of thyroid nodules for thyroid cancer.

PURPOSE OF REVIEW: High-resolution ultrasonography has become mandatory while evaluating patients with thyroid nodules. Although B-mode and Doppler ultrasonography are highly sensitive for diagnosis of thyroid lesions, they lack specificity in differentiating benign from malignant nodules. Ultrasound elastography has proven valuable in discriminating these lesions. This review discusses recent findings regarding the use of elastography as a tool in the evaluation of thyroid masses as well as the different methods and scoring systems used to determine tissue elasticity. RECENT FINDINGS: There are several methods and scores utilized to evaluate the stiffness of normal tissue and solid thyroid lesions, such as strain elastography, acoustic radiation force impulse, and shear wave elastography. Interpretation of data is usually qualitative and subjective obtained with operator-dependent techniques except for shear wave elastography, in which data acquisition is operator-independent with interpretation quantitative and objective in nature. Various software and scoring systems are applied to produce/interpret data resulting in widely variable sensitivity and specificity in differentiating malignant from benign lesions ranging from 73 to 98% and 71 to 100%, respectively. SUMMARY: Although elastography seems promising in identifying malignant thyroid nodules with acceptable accuracy, further studies are necessary to change the current management of thyroid lesions. Consequently, elastography should be used as an additional tool in the work-up of thyroid nodules instead of a single predictor of which lesions should be followed without fine-needle aspiration cytology. Therefore, this exciting methodology, so far, is inadequate to guide the management of thyroid lesions.

A summary of the new phenomenon of normocalcemic hyperparathyroidism and appropriate management.

PURPOSE OF REVIEW: The phenomenon of normocalcemic hyperparathyroidism (NCHPT) remains largely unknown and not well understood. Recently, with more investigators reporting on the subject, NCHPT has been proposed to be a precursor of the classic hypercalcemic primary hyperparathyroidism (HPT). RECENT FINDINGS: This manuscript will discuss the most recent findings regarding the diagnosis, natural history, treatment and follow-up of NCHPT. Approximately 1-4% of patients undergoing parathyroidectomy for HPT are normocalcemic before surgery. To date, observation appears to be a well tolerated approach, as long as these patients remain normocalcemic. When patients with NCHPT are followed for an average of 4 years, 22% will progress to hypercalcemia. In some instances, NCHPT may be treated with parathyroidectomy, but the indications and long-term outcome for this approach are unknown. SUMMARY: This condition is now being diagnosed more frequently. Patients with vitamin D deficiency, mild renal dysfunction, and urinary calcium leak are often mislabeled as having NCHPT and these conditions should always be excluded and medically treated. There is some evidence that parathyroidectomy may be beneficial when NCHPT patients are properly selected. The authors suggest caution when approaching these patients surgically because multiglandular disease and operative failure may be more common in these rare patients.

Case series of targeted parathyroidectomy with surgeon-performed ultrasonography as the only preoperative imaging study.

BACKGROUND: Targeted parathyroidectomy for treatment of sporadic primary hyperparathyroidism (SPHPT) has become the preferred approach in many centers. Therefore, preoperative localization studies are increasingly important. Although surgeon-performed ultrasonography (SUS) is equivalent to sestamibi scanning (MIBI), many surgeons still obtain either a MIBI or both studies before cervical exploration. The goal of this study was to demonstrate the feasibility of targeted parathyroidectomy guided by intraoperative PTH monitoring (IPM) based on SUS localization alone. METHODS: We studied 136 consecutive patients with SPHPT undergoing parathyroidectomy guided by IPM. Ninety-six (71%) patients had only SUS, whereas 40 (29%) also had a negative MIBI (total n = 136). Pre-, intra- and postoperative data were analyzed to evaluate SUS accuracy in localizing abnormal glands. RESULTS: SUS correctly identified ≥ 1 abnormal gland in 90% (123/136) of the patients. Sensitivity and overall accuracy of SUS was 87% and 88%, respectively. Operative success was 99% with multiglandular disease incidence of 10%. Unilateral neck exploration was possible in the majority of patients. CONCLUSION: Preoperative SUS is accurate in localizing hypersecreting glands; however, IPM remains paramount in determining the extent of neck dissection. The use of SUS as a single imaging method obviates the need for MIBI in most patients and decreases costs of parathyroidectomy guided by IPM.

Contemporary and practical uses of intraoperative parathyroid hormone monitoring.

OBJECTIVE: To describe the evolution and current applications of intraoperative parathyroid hormone (PTH) monitoring along with a detailed description of intraoperative protocol and assay methodology. METHODS: Review of the literature regarding the role of intraoperative PTH monitoring in parathyroidectomy, controversies associated with its use in the treatment of hyperparathyroidism, and outcomes using this operative approach. The technologies currently available for "quick" PTH measurement are summarized. RESULTS: Since its inception, intraoperative PTH monitoring has become an essential tool in the endocrine surgeon's armamentarium for treatment of sporadic primary hyperparathyroidism. Intraoperative PTH monitoring changed the operative approach to this disease from bilateral neck exploration with identification of all parathyroid glands and excision based on size, to a highly successful procedure achieved with a limited dissection and gland excision guided by hormone hypersecretion instead of morphologic characteristics. Intraoperative PTH monitoring accuracy is directly associated with the intraoperative criteria used. Although controversy exists regarding the best intraoperative PTH monitoring criteria to be used, most specialized centers have shown excellent results with this intraoperative guidance. Currently, most parathyroid surgeons use intraoperative PTH monitoring, selectively or routinely, during parathyroidectomy. CONCLUSION: Parathyroidectomy guided by intraoperative PTH monitoring to treat sporadic primary hyperparathyroidism is a highly successful and less-invasive approach associated with lower risks than bilateral neck exploration, and it has become the surgical treatment of choice for this disease.

Effectiveness of "office"-based, ultrasound-guided differential jugular venous sampling (DJVS) of parathormone in patients with primary hyperparathyroidism.

BACKGROUND: Pre-operative localization is the first step for focused parathyroidectomy. Surgeon-performed ultrasonography (SUS) is used often as a single method of localization; however, when equivocal, sestamibi (MIBI) scan is still indicated. Intra-operative differential jugular venous sampling (DJVS) is positive in 71-80% of patients. The purpose of this study is to evaluate the effectiveness of office based DJVS as the next method for localization when SUS is equivocal. METHODS: Twenty-one patients with an equivocal SUS underwent office-based, SUS-guided DJVS. The samples were collected from the most inferior portion of each internal jugular vein and sent for standard parathormone (PTH) measurement. The side of the neck with the highest value of serum PTH was the initial side of exploration. DJVS lateralization was correlated retrospectively with operative findings. RESULTS: In 17 of 21 (81%) patients, DJVS was correct in indicating the side of the abnormal gland. DJVS was incorrect in 2 and negative in 2 other patients. Bilateral neck explorations were performed in only 6 of 21 patients because of either multiglandular disease (3 patients), concomitant thyroidectomy (2 patients), or surgeon's judgment (1 patient). There were no complications from DJVS, and all patients became eucalcemic. CONCLUSION: Office based DJVS is accurate and may eliminate the need for MIBI in patients with equivocal SUS. This simple technique can shorten the pre-operative evaluation of sporadic primary hyperparathyroidism.

Recent findings in the use of intraoperative parathyroid hormone monitoring in parathyroid disease.

PURPOSE OF REVIEW: To discuss recent findings and controversies regarding intraoperative parathyroid hormone monitoring (IPM) in guiding parathyroidectomy. RECENT FINDINGS: IPM is being frequently used in guiding surgeons to complete excision of abnormal glands during parathyroidectomy for sporadic primary hyperparathyroidism (SPHPT). This adjunct is now being used in many centers around the world and has become a standard of care in the treatment of SPHPT. As the use of this technique developed, the understanding of what was necessary to return patients with hyperparathyroidism to a eucalcemic state, namely, excision of all parathyroid tissue secreting high amount of parathyroid hormone, was recognized. Two major controversies have developed during the evolution of IPM guided parathyroidectomy. One is that gland excision based on this modality may not recognize all abnormal glands, which, if not excised, will result in operative failure or recurrent hyperparathyroidism. The second disagreement is a technical one and concerns the best intraoperative protocol to be used. SUMMARY: Parathyroidectomy for SPHPT is highly successful regardless of the operative approach used. Despite the controversies summarized in the present review, IPM has been shown to be accurate as an adjunct to guide parathyroidectomy and has changed the operative management of SPHPT.

Long-term outcome of patients with intraoperative parathyroid level remaining above the normal range during parathyroidectomy.

BACKGROUND: Criterion requiring intraoperative parathyroid hormone (IOPTH) drops >50% from the highest, preincision or preexcision level, 10 minutes after the abnormal gland's excision predicts operative success with 98% accuracy. The purpose of this study is to correlate IOPTH dynamics with recurrent hyperparathyroidism (RecHPT) and eucalcemia with high PTH (HPTH). METHODS: We followed 383 consecutive patients with parathyroidectomy guided by IOPTH monitoring using the above criterion for >6 months. Calcium and PTH levels were measured for 50 months (range, 6-173). Patients were divided in 2 groups: group 1 comprised 302 participants with IOPTH levels that decrease to the normal range (NR), and group 2, with 81 participants who had >50% IOPTH decrease but remained above the normal range. The incidence of RecHPT and eucalcemia with HPTH was evaluated. RESULTS: RecHPT was found in 2% (8/383) of patients and eucalcemia with HPTH was present in 19% (74/383). In group 1, 17% (52/302) had eucalcemia with HPTH, whereas in group 2, this incidence was 27% (22/81; P = .04). However, only 2% of those (6/302) in group 1 and 2.5% (2/81) in group 2 developed RecHPT (P = .76). Conversely, 70.5% of those (57/81) in group 2 were eucalcemic with normal PTH. CONCLUSION: Although postoperative eucalcemia with HPTH was significantly higher among patients with IOPTH above the normal range than in patients in group 1, the incidence of RecHPT was not increased. The majority of patients in whom IOPTH did not drop to the normal range continue to be biochemically normal after the operation.

Long-term outcome of patients with elevated parathyroid hormone levels after successful parathyroidectomy for sporadic primary hyperparathyroidism.

HYPOTHESIS: Untreated long-term elevated parathyroid hormone (PTH) levels after successful parathyroidectomy may predict recurrent hyperparathyroidism (HPT). Although elevated PTH levels have been reported in eucalcemic patients after parathyroidectomy for sporadic primary HPT, the long-term clinical significance of this finding remains unclear. DESIGN: Retrospective case series. SETTING: Tertiary referral center. PATIENTS: Five hundred seventy-six consecutive patients with HPT. INTERVENTION: Parathyroidectomy guided by intraoperative monitoring of PTH levels. MAIN OUTCOME MEASURES: Overall incidence of elevated PTH levels (measurements of >or= 70 pg/mL at any time during follow-up) and recurrent HPT (hypercalcemia and elevated PTH levels more than 6 months after parathyroidectomy). RESULTS: Of the 505 patients who underwent successful parathyroidectomy in this series and were followed up for more than 6 months, 337 (66.7%) consistently had PTH levels within the reference range, and 168 (33.3%) had elevated PTH levels. Of the 168 patients with elevated PTH levels, only 8 (4.8%) developed recurrent disease. The earliest recurrence occurred 2 years postoperatively. Factors associated with elevated PTH levels included advanced age, higher preoperative PTH levels, and mild postoperative renal insufficiency. CONCLUSION: Although one-third of the patients had elevated PTH levels after successful parathyroidectomy, most of these patients with elevated PTH levels (95%) will achieve long-term eucalcemia.

Role of intraoperative parathormone monitoring during parathyroidectomy in patients with discordant localization studies.

BACKGROUND: Many patients with sporadic primary hyperparathyroidism (SPHPT) have discordant preoperative Tc-99m-sestamibi (MIBI) and ultrasonography studies prior to focused parathyroidectomy (PTX). This study examines the usefulness of intraoperative parathormone monitoring (IPM) during PTX in patients with discordant preoperative localization studies. METHODS: A retrospective series of 225 consecutive SPHPT patients with MIBI scans and surgeon performed ultrasonography (SUS) prior to focused parathyroidectomy were studied. All patient operations were reviewed, and how IPM changed operative management was determined. Correct gland localization, presence of multigland disease (MGD), and operative outcome were also examined. RESULTS: In 225 patients, overall operative success was 97%, and IPM changed operative management in 29% of patients. In 85 patients (38%) with discordant studies, operative success was 93%; IPM changed operative management in 74% of these patients. IPM allowed for 66% (56/85) of these operations to be performed as unilateral neck exploration and confirmed removal of abnormal glands in 7 patients with MGD. In 140 patients (62%) with concordant localization, in which operative success was 99%, IPM changed operative management in only 2% (3/140) of these patients with MGD. CONCLUSION: Although of marginal benefit in patients with concordant imaging studies, IPM remains essential for performing successful PTX with discordant or incorrect concordant localization.

Consequences of parathyroidectomy in patients with "mild" sporadic primary hyperparathyroidism.

BACKGROUND: The use of a targeted, less-invasive approach is changing the operative indications in sporadic primary hyperparathyroidism (SPHPT). Now, patients with "mild" HPT are offered parathyroidectomy. However, the operative findings and outcome of these patients are unknown. This study reports the differences between "mild" and "classic" biochemical SPHPT in incidence of multiglandular disease (MGD) and operative outcome. METHODS: All 343 patients underwent parathyroidectomy guided by intraoperative parathyroid hormone (PTH) monitoring (IPM). Among them, 301 patients (88%) had "classic" biochemical SPHPT (hypercalcemia and increased PTH) and 42 patients (12%) had "mild" HPT, which consisted of 28 patients with inappropriate secretion of PTH (ISP-hypercalcemia and normal PTH), and 14 patients with normocalcemic HPT (NCHPT-eucalcemia and increased PTH). Single or MGD was determined by IPM. Operative success is eucalcemia for greater than or equal to 6 months after operation and along with normal PTH levels in NCHPT. RESULTS: Thirty nine of 301 patients (13%) with "classic" biochemical SPHPT had MGD with an operative failure rate of 1% (3/301). In the "mild" HPT group, 14 of 42 patients (33%) had MGD with a failure rate of 5% (2/42). The incidence of MGD was statistically significant (P < .001). CONCLUSION: The incidence of MGD and operative failure are higher in patients with "mild" HPT when compared with classic SPHPT. Patients and surgeons should be aware of these consequences when parathyroidectomy is offered to patients with "mild" HPT.