Parathyroid, Thyroid and Recurrent Laryngeal Nerve Anatomy in an Indian Rhinoceros (Rhinoceros unicornis).

INTRODUCTION: The parathyroid gland was first identified in the Indian rhinoceros in 1849 by Sir Richard Owen. We performed a necropsy in an Indian rhinoceros, recapitulating Owen's dissection and display what appear to be the initial identification of the recurrent laryngeal nerve in situ and the anatomy and histology of the largest rhinoceros parathyroid glands yet identified. MATERIALS AND METHODS: Patrick T. Rhino, a 41-year-old Indian rhinoceros was born in 1974. His early years were unremarkable. In 2006, he was donated to White Oak Conservation in Yulee, Florida, where he bred and sustained minor injuries. In his geriatric years, he developed a cataract and degenerative joint disease (DJD). At age 41, he developed progressive ataxia and lameness and was euthanized to minimize suffering when he was unable to stand. ROS, FH, SH and medication history were unremarkable. Physical exam was age and species appropriate. Pre-mortem serum demonstrated: creat 1.8 mg/dL (0.8-2.1), calcium 10.6 mg/dL (9.7-13.1), phos 3.8 mg/dL (2.5-6.7), alk phos 69 U/L (26-158) and intact PTH 44.1 pg/mL (rhinoceros reference range: unknown). Necropsy revealed intervertebral DJD with thoracic spondylosis, which combined with osteoporosis, resulted in thoracic myelopathy and ataxia. The neck block was sent in formalin to the Yale University School of Medicine. RESULTS: Detailed dissection was performed under loupe magnification. Presumed structures were photographed in situ and biopsied. The thyroid was identified deep to the strap muscles, received its blood supply from the inferior and superior thyroid arteries and was blue in color. The right recurrent laryngeal nerve, identified and photographed in situ for the first time in the rhinoceros, was deep to the inferior thyroid artery and was traced throughout its cervical course. Single parathyroid glands identified on the lateral thyroid lobes received their blood supply from the inferior thyroid arteries and were confirmed histologically. They appear to be the largest parathyroids yet identified in the rhinoceros with estimated weights of 6,280 and 11,000 mg, respectively. Although the etiology of the parathyroid gland enlargement is unknown, the specimen has been preserved recapitulating the dissection performed by Sir Richard Owen. CONCLUSION: The parathyroids, thyroid and recurrent laryngeal nerve were identified in an Indian rhinoceros. This appears to be the first display of the rhinoceros recurrent laryngeal nerve in situ, and the parathyroid glands are the largest yet identified in the rhinoceros.

Randomized prospective evaluation of frozen-section analysis for follicular neoplasms of the thyroid.

OBJECTIVE: To evaluate the clinical utility of frozen section in patients with follicular neoplasms of the thyroid in a randomized prospective trial. SUMMARY BACKGROUND DATA: The finding of a follicular neoplasm on fine-needle aspiration prompts many surgeons to perform intraoperative frozen section during thyroid lobectomy. However, the focal distribution of key diagnostic features of malignancy contributes to a high rate of noninformative frozen sections. METHODS: The series comprised 68 consecutive patients with a solitary thyroid nodule in whom fine-needle aspiration showed a follicular neoplasm. Patients were excluded for bilateral or nodal disease, extrathyroidal extension, or a definitive fine-needle aspiration diagnosis. Final pathologic findings were compared with frozen sections, and cost analyses were performed. RESULTS: Sixty-one patients met the inclusion criteria. Twenty-nine were randomized to the frozen-section group and 32 to the non-frozen-section group. In the non-frozen-section group, one patient was excluded when gross examination of the specimen was suggestive of malignancy and a directed frozen section was diagnostic of follicular carcinoma. Frozen-section analysis rendered a definitive diagnosis of malignancy in 1 of 29 (3.4%) patients, who then underwent a one-stage total thyroidectomy. In the remaining 28 patients, frozen section showed a "follicular or Hürthle cell neoplasm." Permanent histology demonstrated well-differentiated thyroid cancer in 6 of these 28 patients (21%). Of the 31 patients in the non-frozen-section group, 3 (10%) showed well-differentiated thyroid carcinoma on permanent histology. Complications were limited to one transient unilateral vocal cord dysfunction. All but one patient had a 1-day hospital stay. There were no significant differences between the groups in surgical time or total hospital charges; however, the charge per informative frozen section was approximately $12,470. CONCLUSIONS: For the vast majority of patients (96.4%) with follicular neoplasms of the thyroid, frozen section is neither informative nor cost-effective.

One hundred consecutive minimally invasive parathyroid explorations.

OBJECTIVE: To review the outcomes of 100 consecutive minimally invasive parathyroid explorations. SUMMARY BACKGROUND DATA: Minimally invasive parathyroidectomy (MIP) has challenged the traditional approach of bilateral neck exploration for patients with primary hyperparathyroidism. Most patients with primary hyperparathyroidism have a single adenoma that when resected results in cure. It therefore appears logical to perform a directed approach to adenoma extirpation. MIP involves high-quality sestamibi images obtained with single photon emission computed tomography to localize enlarged parathyroid glands in three dimensions, limited exploration after surgeon-administered cervical block anesthesia, rapid intraoperative parathyroid hormone assay to confirm the adequacy of resection, and discharge within 1 to 3 hours of surgery. METHODS: MIP was offered to 100 selected consecutive patients during an 18-month period beginning in March 1998. RESULTS: Ninety-two cases were accomplished under cervical block anesthesia and 89 of these on an ambulatory basis. The cure rate was 100%, and there were no long-term complications. The mean hospital charge for MIP was less than 40% of that associated with traditional exploration. CONCLUSIONS: Outpatient MIP appears to be the procedure of choice for most patients with primary hyperparathyroidism.