A patient with persistent primary hyperparathyroidism due to a second ectopic adenoma

Selective venous sampling in primary hyperparathyroidism caused by ectopic parathyroid gland: a case report and literature review

BACKGROUND

As an invasive technique, selective venous sampling (SVS) is considered a useful method to identify a lesion's location to increase the success rate of secondary surgery in patients with primary hyperparathyroidism (pHPT) caused by ectopic parathyroid adenomas.

CASE PRESENTATION

We present a case of post-surgical persistent hypercalcemia and elevated parathyroid hormone (PTH) levels in a 44-year-old woman with previously undetected parathyroid adenoma. An SVS was then performed for further localization of the adenoma, as other non-invasive methods showed negative results. After SVS, an ectopic adenoma was suspected in the sheath of the left carotid artery, previously considered as a schwannoma, and was pathologically confirmed after the second operation. Postoperatively, the patient's symptoms disappeared and serum levels of PTH and calcium normalized.

CONCLUSIONS

SVS can provide precise diagnosis and accurate positioning before re-operation in patients with pHPT.

Limitations of Tc99m-MIBI-SPECT imaging scans in persistent primary hyperparathyroidism

Background

In primary hyperparathyroidism (PHPT) the predictive value of technetium 99m sestamibi single emission computed tomography (Tc99m-MIBI-SPECT) for localizing pathological parathyroid glands before a first parathyroidectomy (PTx) is 83–100%. Data are scarce in patients undergoing reoperative parathyroidectomy for persistent hyperparathyroidism. The aim of the present study was to determine the value of Tc99m-MIBI-SPECT in localizing residual hyperactive parathyroid tissue in patients with persistent primary hyperparathyroidism (PHPT) after initial excision of one or more pathological glands.

Method

We retrospectively evaluated the localizing accuracy of Tc99m-MIBI-SPECT scans in 19 consecutive patients with persistent PHPT who had a scan before reoperative parathyroidectomy. We used as controls 23 patients with sporadic PHPT who had a scan before initial surgery.

Results

In patients with persistent PHPT, Tc99m-MIBI-SPECT accurately localized a pathological parathyroid gland in 33% of cases before reoperative parathyroidectomy, compared to 61% before first PTx for sporadic PHPT. The Tc99m-MIBI-SPECT scan accurately localized intra-thyroidal glands in 2 of 7 cases and a mediastinal gland in 1 of 3 cases either before initial or reoperative parathyroidectomy.

Conclusions

Our data suggest that the accuracy of Tc99m-MIBI-SPECT in localizing residual hyperactive glands is significantly lower before reoperative parathyroidectomy for persistent PHPT than before initial surgery for sporadic PHPT. These findings should be taken in consideration in the preoperative workup of patients with persistent primary hyperparathyroidism.

Bioorganometallic chemistry--from teaching paradigms to medicinal applications

In undergraduate level organometallic chemistry courses students are usually taught that organometallic compounds are toxic and unstable in air and water. While this is true of many complexes, some are also non-toxic and stable in air and water. Indeed, bioorganometallic chemistry, the study of biomolecules or biologically active molecules that contain at least one carbon directly bound to a metal, is a thriving subject, and air and water stability is a general pre-requisite. This interdisciplinary field is located at the borderline between chemistry, biochemistry, biology and medicine. In this tutorial review, various aspects of bioorganometallic chemistry are introduced, with the main emphasis on medicinal organometallic compounds. Organometallic therapeutics for cancer, HIV and malaria and other medicinal applications are described. It is also shown how rational ligand design has led to new improved therapies much in the same way that an organometallic chemist working in catalysis will design new ligands for improved activities.