Imaging Sciences Interesting Cases
Case 66
Richard Gong, MD
Clinical Presentation: Patient is a 50-year-old asymptomatic woman with elevated parathyroid hormone and calcium.
Imaging Findings: Persistent uptake at the left lower thyroid lobe on delayed images from technetium sesamibi scan.
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| Figure 1. Focal radiotracer uptake overlying the left thyroid lobe. |
Diagnosis: Parathyroid Adenoma
Discussion: Primary hyperthyroidism is caused by a single adenoma in 80% to 90% of cases. Any one of the four parathyroid gland may be involved with equal frequency. In a minority of patient parathyroid adenomas may be located in the thymus, the thyroid, the pericardium, or behind the esophagus. Chief cells predominate in parathyroid adenoma. The adenoma may sometime be surrounded by a rim of normal tissue.
Multiple gland involvement is more commonly due to hyperplasia and less commonly due to multiple adenomas. Because distinguishing hyperplasia from adenoma is difficult pathologically, they are often histologically considered together as multiple gland disease.
Treatment can be either medical or surgical. Surgical intervention for a solitary adenoma usually involves 4-gland exploration to assess for mutigland involvement followed by excision of the adenoma with intraoperative PTH level monitoring.
References:
- Huppert B, Reading C. The parathyroid glands. In: Rumack C,Wilson S, Charboneau JW, Johnson JA (Eds.): Diagnostic Ultrasound, St. Louis, Mosby, 2005:773.
- Braunwald E, Fauci AS, Kasper DL, et al. (Eds.). Harrison's Principles of Internal Medicine, 15th Ed. New York, McGraw Hill, 2001:2210-13.