Mediastinal Intrathymic Parathyroid Adenoma: A Case Report and Review of the Literature.

The classic clinical vignette of primary hyperparathyroidism is well described as "bones, stones, abdominal moans, and psychiatric overtones" to reflect the effects of excess parathyroid hormone (PTH) and calcium. Most commonly, primary hyperparathyroidism is due to a functional parathyroid adenoma situated by the thyroid gland. Rarely, the primary focus of autonomously produced PTH is located ectopically within the mediastinum. A 19-year-old Caucasian female with no relevant past medical history presented to the emergency department with tachycardia, nausea, vomiting, and a five-day history of vague, mid-abdominal pain. Initial computed tomography (CT) with contrast of the abdomen and pelvis was negative for acute findings, and she subsequently underwent biochemical screening. The patient was found to have elevated serum calcium and PTH, raising suspicion for the diagnosis of primary hyperparathyroidism. Further evaluation for a parathyroid adenoma was negative by a CT scan of the neck and thyroid ultrasound. A nuclear medicine parathyroid single-photon emission computed tomography (SPECT)/CT with technetium (Tc) 99m sestamibi found an abnormal nodular uptake within the left prevascular mediastinum suggestive of an ectopic parathyroid adenoma. A left-sided, video-assisted thoracoscopic surgery (VATS) with successful excision of the ectopic mediastinal parathyroid adenoma was performed. Surgical pathology revealed that the parathyroid adenoma was completely excised and surrounded by thymus and adipose tissue. The patient tolerated the procedure well and was discharged without further complications. The rarity of mediastinal, intrathymic parathyroid adenomas resulted in delayed diagnosis in this patient, understandably so as errant embryogenesis does not occur commonly. Visualization with SPECT/CT and successful specimen excision by minimally invasive VATS resulted in the accurate diagnosis and ultimate cure of this patient's primary hyperparathyroidism.

Accuracy of cricothyroidotomy performed in canine and human cadaver models during surgical skills training.

BACKGROUND: Surgical skills training is an integral component of the Advanced Trauma Life Support (ATLS) Course. Teaching techniques are continuously reevaluated and updated. Recognition of recurring technical errors in the performance of cricothyroidotomy in canine models prompted this comparison to the performance of the procedure in human cadavers. STUDY DESIGN: Thirty-three ATLS physician students performed cricothyroidotomy in canine models. Ten flight nurses performed a bimonthly surgical skills practicum on similarly prepared animals. Neck specimens were excised, fixed, and later mapped by the investigators. Subsequent courses used human cadavers obtained through the Wright State University School of Medicine Anatomical Gift Program. Cricothyroidotomy sites were mapped in situ. RESULTS: In the canine models, 47 necks with 52 attempted cricothyroidotomies were inspected and mapped by the investigators. Four specimens had multiple tracheotomy sites: three had two and one had three. If these multiple attempts are excluded from analysis, 13 of the 43 cricothyroidotomies in the canine models were misplaced (30.2%). Cricothyroidotomy placement in human cadavers was correct in 27 of 28 attempts (96.4%). CONCLUSIONS: It is imperative that cricothyroidotomy, a high-risk procedure, be taught in an appropriate model to best prepare students to perform it in a life-saving situation. Placement accuracy in canine models is low. Alternative models for teaching this procedure should be considered.