Intrathyroidal carotid artery and nonrecurring right recurrent laryngeal nerve: A case report.

BACKGROUND: When performing thyroidectomy, knowledge of normal anatomy and variants is vital to avoid injuring nearby structures. Typically, the bilateral carotids course posterolateral to the thyroid gland. We describe a rare variant of an intrathyroidal carotid artery, not previously described in the literature. METHODS: A 23-year-old woman with a strong family history of thyroid cancer presented with a left thyroid nodule, and a fine-needle aspiration biopsy revealing papillary thyroid carcinoma. She underwent total thyroidectomy. RESULTS: Intraoperatively, the carotid was found coursing centrally through the right lobe parenchyma, associated with an ipsilateral nonrecurrent recurrent laryngeal nerve (NRLN) entering the cricothyroid joint superolaterally. CONCLUSION: This is, to our knowledge, the first report of such an anatomic variant in the medical literature. Aberrant carotid artery anatomy may potentially cause life-threatening surgical complications and should be considered preoperatively. Furthermore, recognition of concurrent recurrent laryngeal nerve (RLN) anomalies with vascular variations allows identification of nonrecurrent nerves.

IgG4-Related Disease Presenting as a Solitary Neck Mass.

IgG4-related disease is a newly recognized entity associated with autoimmune conditions involving almost every organ system. It is characterized by elevated serum IgG4 as well as mass like tissue infiltration by IgG4-positive plasma cells. Imaging findings are nonspecific, vary depending on the site of disease, and include mass like enlargement of the salivary or lacrimal glands and enlarged lymph nodes. Radiographic findings often mimic malignancy, necessitating tissue sampling to confirm the diagnosis. Distinguishing IgG4-related disease from malignancy is important as IgG4 responds well to steroids and conservative management.

Time-resolved NMR: extracting the topology of complex enzyme networks.

The use of nondestructive NMR spectroscopy for enzymatic studies offers unique opportunities to identify nearly all enzymatic byproducts and detect unstable short-lived products or intermediates at the molecular level; however, numerous challenges must be overcome before it can become a widely used tool. The biosynthesis of acetyl-coenzyme A (acetyl-CoA) by acetyl-CoA synthetase is used here as a case study for the development of an analytical NMR-based time-course assay platform. We describe an algorithm to deconvolve superimposed spectra into spectra for individual molecules, and further develop a model to simulate the acetyl-CoA synthetase enzyme reaction network using the data derived from time-course NMR. Simulation shows indirectly that synthesis of acetyl-CoA is mediated via an enzyme-bound intermediate (possibly acetyl-AMP) and is accompanied by a nonproductive loss from an intermediate. The ability to predict enzyme function based on partial knowledge of the enzymatic pathway topology is also discussed.