Lower thigh subcutaneous and higher visceral abdominal adipose tissue content both contribute to insulin resistance.

It is well known that visceral adipose tissue (VAT) is associated with insulin resistance (IR). Considerable debate remains concerning the potential positive effect of thigh subcutaneous adipose tissue (TSAT). Our objective was to observe whether VAT and TSAT are opposite, synergistic or additive for both peripheral and hepatic IR. Fifty-two volunteers (21 male/31 female) between 30 and 75 years old were recruited from the general population. All subjects were sedentary overweight or obese (mean BMI 33.0 ± 3.4 kg/m(2)). Insulin sensitivity was determined by a 4-h hyperinsulinemic-euglycemic clamp with stable isotope tracer dilution. Total body fat and lean body mass were determined by dual X-ray absorptiometry. Abdominal and mid-thigh adiposity was determined by computed tomography. VAT was negatively associated with peripheral insulin sensitivity, while TSAT, in contrast, was positively associated with peripheral insulin sensitivity. Subjects with a combination of low VAT and high TSAT had the highest insulin sensitivity, subjects with a combination of high VAT and low TSAT were the most insulin resistant. These associations remained significant after adjusting for age and gender. These data confirm that visceral excess abdominal adiposity is associated with IR across a range of middle-age to older men and women, and further suggest that higher thigh subcutaneous fat is favorably associated with better insulin sensitivity. This strongly suggests that these two distinct fat distribution phenotypes should both be considered in IR as important determinants of cardiometabolic risk

Primary Paraganglioma of the Parathyroid: A Case Report and Clinicopathologic Review

Paragangliomas are relatively uncommon neoplasms that arise in adrenal and extra-adrenal paraganglia of the autonomic nervous system. Parasympathetic paraganglioma develop predominantly in the head and neck. It is exceedingly uncommon to develop a primary intraparathyroid paraganglioma. There is only a single case report in the English literature. The information from the single previous case report (Medline 1960–2009) was combined with this case report. Our patient was a 69 year old woman who presented with a thyroid gland mass, with extension into the substernal space. The patient had a history of renal cell carcinoma removed 18 months before. At surgery, a thyroid lobectomy and a parathyroidectomy were performed. The parathyroid tissue showed a very well defined zellballen arrangement of paraganglion cells within the parenchyma of the parathyroid gland. The cells had ample basophilic, granular cytoplasm. The nuclei were generally round to oval with ‘salt-and-pepper’ nuclear chromatin distribution. There was a richly vascularized stroma. Mitotic figures, necrosis, invasive growth, and profound nuclear pleomorphism were absent. The neoplastic cells were strongly and diffusely immunoreactive with chromogranin, synaptophysin, CD56, and focally with cyclin-D1. The paraganglioma showed a delicate S-100 protein positive supporting sustentacular framework. Keratin, CD10, PTH, calcitonin and RCC markers were negative. The patient showed no stigmata of Multiple Endocrine Neoplasia (MEN) and has no paraganglioma in any other anatomic site. She is alive without any additional findings 12 months after surgery. Isolated paraganglioma within the parathyroid is rare, and should be separated from parathyroid adenoma, hyperplasia or metastatic disease to assure appropriate management