What's new in general surgery: endocrine surgery

Case Report: Primary Hyperparathyroidism due to Posterior Mediastinal Parathyroid Adenoma With One-Year Follow-Up

Ectopic parathyroid adenoma, though rare, is one of the causes of persistent hyperparathyroidism and recurrence of hyperparathyroidism. Ectopic parathyroid glands can be seen in thymus, thyroid, and mediastinum. However, ectopic parathyroid adenoma occurred in the posterior superior mediastinum is extremely rare. Here, we report a case of primary hyperparathyroidism caused by ectopic parathyroid adenoma located in the posterior superior mediastinum. Serum parathyroid hormone, calcium, and vitamin D levels of the patient was followed up for one year.

Primary hyperparathyroidism caused by an ectopic parathyroid adenoma in an uncommon location: a case report

Primary hyperparathyroidism caused by an ectopic parathyroid adenoma in the mediastinum is a rare clinical condition. We present a 75-year-old male with primary hyperparathyroidism caused by an ectopic parathyroid adenoma in the mediastinum. This patient was initially referred to the clinic for suspected incidental hypercalcemia. Initial imaging showed two suspicious lesions: one adjacent to the thyroid gland and another in the mediastinum. Further investigations identified a sole mediastinal adenoma. The diagnosis was confirmed by normalization of parathyroid hormone levels after its surgical resection. Thoroughly diagnosing such cases can prove challenging and using a single modality such as ultrasonography, computed tomography, or nuclear imaging alone may not yield conclusive findings or can give false positive results. Our case demonstrates that a combination of several imaging modalities can lead to accurate localization of the cause of primary hyperparathyroidism. This will obviate the performance of unnecessary surgical procedures. In addition, the possibility of missing additional sources of ectopic secretions of the parathyroid hormone will be reduced.

Management of mediastinal parathyroid adenoma via minimally invasive thoracoscopic surgery: Case report

INTRODUCTION

The most common cause of chronic hypercalcemia is primary hyperparathyroidism (PHPT). However, owing to the diverse presentation of hypercalcemia, the diagnosis often goes unnoticed culminating as a continuum of recurrence of symptoms. Nephrolithiasis, decreased bone mineral density and peptic ulcer disease are the main clinical sequelae. Among the causes of PHPT 80% are caused by parathyroid adenomas (PA). However, only rarely, these adenomas are found ectopically.

PRESENTATION OF CASE

We present the case of a 66-year-old female with a history of recurrent renal stones and peptic ulcer disease. She was found to have elevated serum calcium and PTH levels. However, subsequent high resolution CT scan of chest and neck failed to demonstrate any abnormality. Therefore, an anterior planar Technetium-99m-sestamibi (MIBI) scintigraphy scan using a single-tracer was done and it identified ectopic anterior mediastinal parathyroid adenoma. The patient was successfully managed with video-assisted thoracoscopic surgery and excision of the mass with follow up calcium level monitoring.

DISSCUSSION

An elevated calcium level should prompt a thorough workup, as sometimes it's the only clue to the unrelated and diversified systemic manifestations of hypercalcemia. Hyperparathyroidism due to ectopic adenoma is quite rare and possess a diagnostic and management challenge.

CONCLUSION

Symptomatic hypercalcemia and high level of PTH without local PA should alert physicians to search for ectopic locations through imaging. VATS is a safe and effective minimally invasive procedure for the resection of ectopic mediastinal PA and it should be considered as the first line approach for resection of these ectopic tumors.

A case report of mediastinal ectopic parathyroid adenoma presented as parathyroid crisis localized by SPECT/CT

INTRODUCTION

Parathyroid crisis due to ectopic parathyroid adenomas can pose diagnostic and management challenges, since it is quite rare in clinical practice.

CLINICAL FINDINGS/PATIENT CONCERNS

A 67-year-old Chinese male presented as a parathyroid crisis due to an ectopic mediastinal parathyroid adenoma with his serum calcium and PTH markedly increased in short time. An ultrasonography and computed tomography (CT) scan of the neck did not reveal any parathyroid adenoma. Thoracic CT detected a contrast-enhanced mass in the mediastinum. Although the ectopic location is difficult to appreciate on anterior planar technetium-99m-sestamibi scintigraphy views but has been accurately localized with single photon-emission computed tomography/computed tomography. After fluid resuscitation, loop diuretic, and calcitonin treatment, a thoracoscope surgery was performed. The histopathology of the mediastinal nodule was consistent with a parathyroid adenoma. Hypocalcemia due to hungry bone syndrome occurred after surgery and was resolved quickly with large-dose calcium and calcitriol supplementation. He is asymptomatic and has normal serum calcium and PTH levels on regular follow-up.

DIAGNOSES

The ultrasonography, CT, sestamibi, and single photon-emission computed tomography/computed tomography provide limited sensitivity in the detecting ectopic parathyroid adenomas alone. The combination of these techniques has incremental value in localizing ectopic parathyroid adenomas over either technique alone.

CONCLUSION

Any parathyroid crisis without parathyroid adenoma in the neck should alert physicians to search for ectopic locations through combination of imaging techniques.

Current concepts in the management of primary hyperparathyroidism

Primary hyperparathyroidism is the commonest cause of hypercalcemia in the ambulatory setting. Widespread use of routine laboratory screening has resulted in a large number of patients presenting with subclinical disease. In truly asymptomatic patients, consensus guidelines have been developed to determine which patients need definitive treatment. The most common pathologic finding is parathyroid adenoma, followed by hyperplasia, double adenomas and parathyroid carcinoma. The mainstay of treatment is surgery. While there is still an important role for four gland exploration and evaluation, there is now considerable interest in a more focused surgical approach. This paradigm shift is based on localizing studies that combine sestamibi scanning with anatomic imaging, most commonly ultrasound scanning. A range of minimally invasive approaches have been developed to treat parathyroid adenomas, including unilateral and single gland explorations as well as a number of different endoscopic techniques. Intra-operative rapid parathormone assay has replaced histologic examination as a more effective method to confirm the adequacy of surgery in most cases. Functional localization and exploration using a gamma probe has also been described. The management of patients with persistent or recurrent hyperparathyroidism is difficult and requires a multidisciplinary approach.

Ectopic mediastinal parathyroid adenoma: a cause of acute pancreatitis

A 38-year-old male was admitted to our hospital with epigastric pain, and he was confirmed to have acute exudative pancreatitis. After the episode of acute pancreatitis subsided, laboratory investigation revealed increased serum calcium (12.0 mg/dl), decreased serum phosphorus (2.7 mg/dl), and increased serum parathyroid hormone (intact) levels (131 pg/ml). A computed tomography (CT) scan of the neck did not reveal any mass lesions in the parathyroid gland. However, (99m)Tc sestamibi scintigraphy revealed that there was one functioning parathyroid gland in the upper mediastinum. Combined (99m)Tc sestamibi scintigraphy and CT scan confirmed the diagnosis of primary hyperparathyroidism in the mediastinum. Microscopic examination revealed the presence of a parathyroid adenoma (1.3 x 0.4 cm(2)) adjacent to the atrophic parathyroid gland in right thymus gland. We report the case of a patient diagnosed with primary hyperparathyroidism due to an ectopic mediastinal parathyroid adenoma. An ectopic mediastinal parathyroid adenoma may manifest as an episode of acute pancreatitis. Preoperative investigation to determine the exact location of an adenoma should include two types of imaging studies, preferably (99m)Tc sestamibi scintigraphy and CT of the neck and chest.

Nuclear imaging and minimally invasive surgery in the management of hyperparathyroidism

Primary hyperparathyroidism is the most common cause of hypercalcemia, and the treatment is primarily surgical. Because of biochemical screening, more patients now present with asymptomatic primary hyperparathyroidism, and consensus guidelines have been developed for the treatment of these patients. There is now considerable interest in minimally invasive approaches to the treatment of hyperparathyroidism. Sestamibi scanning as a localizing study, used in combination with anatomic imaging and intraoperative rapid parathyroid hormone assays, has enabled focused surgical approaches. Patients with localizing studies that indicate a single parathyroid adenoma are candidates for such approaches, including unilateral neck exploration, minimally invasive single-gland exploration, or endoscopic exploration instead of the traditional approach of bilateral neck exploration. Nuclear imaging is also critical to the successful management of patients with persistent or recurrent hyperparathyroidism.

Assessment and therapy of selected endocrine disorders

Diabetes remains the most commonly encountered endocrinopathy with the incidence of type 2 doubling in the past decade. The prevalence of diabetes is projected to continue to increase dramatically over the next several decades unless major public health initiatives are successful in stemming this growth. Both type I and 2 diabetics more frequently require surgical and critical care than their non-diabetic counterparts. Type 1 and 2 diabetics also sustain greater peri-operative morbidity and mortality. Careful preoperative assessment and appropriate perioperative intervention may limit this. There is increasing evidence that maintenance of normal blood glucose in the perioperative period and during critical illness is beneficial for diabetic and non-diabetic patients. More data will hopefully be forthcoming to substantiate recent reports and identify the mechanisms of improved outcome. Thyroid disease remains a commonly encountered pathology that is more readily identified and controlled in the modern era of radioimmune assays of thyroid hormone and successful medical and surgical therapies. Severe hypothyroidism and thyroid storm are associated with significant increases in perioperative morbidity and mortality. Recognition of these entities or those at risk for developing them post operatively is crucial in initiating timely and effective therapy. Primary Al is uncommon, but results in glucocorticoid and mineralocorticoid deficiency. Tertiary Al is far more common, most often secondary to iatrogenic therapy with exogenous glucocorticoids for the management of chronic diseases such as connective tissue disorders, anti-rejection regimes, and severe asthma. Glucocorticoid replacement or supplementation is needed on a case-by-case basis and should be individualized based on chronic steroid dose, duration, and stress of the surgical procedure. Perioperative steroid dosing regimes now recommend lower doses for shorter periods than previously suggested. More recently Al has been recognized in two populations, elderly patients undergoing major surgery and a subgroup of patients with septic shock. Timely diagnosis using synthetic ACTH stimulation testing and stress glucocorticoid, and possibly mineralocorticoid therapy, seems to reverse these processes and improve recovery. Although uncommon, patients with pheochromocytoma who undergo open or laparoscopic resections remain diagnostic and therapeutic challenges. Perioperative outcome seems to have improved, in part, related to newer therapies and less invasive surgeries when indicated. The appropriate preoperative assessment and management of patients with various endocrinopathies is important to optimize outcome and limit avoidable complications. Hopefully additional evidence based guidelines will be forth-coming particularly in caring for the ever increasingly encountered perioperative diabetic.

Intravenous methylene blue as an aid to intraoperative localization and removal of the adrenal glands during laparoscopic adrenalectomy

BACKGROUND

We hypothesized that intravenous methylene blue will facilitate adrenal gland identification and resection during laparoscopic adrenalectomy.

METHODS

Five mini-Hanford pigs were anesthetized and monitored per an approved Internal Review Board protocol. Timing of color changes in the adrenals was recorded after administering methylene blue at three different doses: 2.5 mg/kg, 5.0 mg/kg, and 7.5 mg/kg. The time required for laparoscopic adrenalectomy with and without methylene blue was recorded.

RESULTS

No color change occurred after the 2.5 mg/kg dose. For the 7.5 mg/kg versus the 5.0 mg/kg dose there was a more rapid bluish color change (mean time, 1.89 minutes versus 3.45 minutes; P = 0.03) and a longer duration of bluish color change (mean time, 12.20 minutes versus 6.19 minutes; P = 0.01). Laparoscopic adrenalectomy using methylene blue resulted in a 34.5% faster median resection time (10.13 minutes versus 15.47 minutes).

CONCLUSIONS

Methylene blue concentrates in the adrenal glands and facilitates identification and resection of the adrenal glands by a laparoscopic approach.

The False Negative Technetium-99m-Sestatnibi Scan in Patients with Primary Hyperparathyroidism: Correlation with Clinical Factors and Operative Findings

False negative (FN) results limit the efficacy of technetium-99m-sestamibi scanning for parathyroid localization. We determined the incidence of FN results and attempted to correlate it with clinical and operative findings. One hundred forty-six patients underwent parathyroidectomy; 89 had primary hyperparathyroidism (76 single adenoma and 13 multiglandular disease) and underwent sestamibi scanning. The false negative rate was 22 per cent with an overall sensitivity of 77 per cent and a positive predictive value of 99 per cent. Patients with single adenomas were more likely to have a true positive scan than those with multiglandular disease [83% vs 38%; odds ratio (OR) = 7.754, 95% confidence interval (CI) = 2.184–27.524; P ≤ 0.0001]. Inferior adenomas (90% vs 59%; OR = 6.261,95% CI = 2.037–19.243; P ≤ 0.0001) and larger adenomas (1422.3 ± 1576.2 vs 474.6 ± 193.2 g; P ≤ 0.0001) were more likely to be detected by sestamibi imaging. Patients with normal preoperative calcium levels were more likely to have an FN sestamibi scan. Sestamibi parathyroid imaging is limited by a 22 per cent FN rate and is less accurate for detecting abnormal parathyroid tissue in patients with small adenomas, multiglandular disease, superior adenomas, or preoperative normocalcemia.