RAD5 Thyroid cancer presenting as an autonomous nodule. (Radiology).

RAD5 THYROID CANCER PRESENTING AS AN AUTONOMOUS NODULE. Cynthia I. Powers, MD, and W. Mel Flowers, Jr., MD. University of Mississippi Medical Center, Jackson.

Thyroid carcinoma usually presents as a cold nodule on nuclear medicine scans. We report an unusual case of an autonomous hot nodule suppressing the remainder of the gland that was found to be a papillary carcinoma, follicular variant, on final pathological diagnosis. A 58-year-old female was seen by the OB-GYN service. A palpable nodule in the left side of the thyroid gland was discovered. A fine needle aspiration biopsy was performed and reported as benign adenomatous cells. Following a TSH-measurement of 0.174 (normal, 0.4-5.5), the patient was sent to the Nuclear Medicine Department for radioactive iodine uptake and imaging. The 24-hour uptake was 10.4% (normal 10-35%). The image of the thyroid gland demonstrated a rounded focus of intense activity in the expected position of the left thyroid lobe. There was no discernable activity in the right lobe. This appearance was typical of an autonomous left thyroid nodule that had suppressed the function of the remainder of the gland. Parathyroid imaging was requ ested because of a serum calcium of 10.8 (normal 8.8-10.1). Marked asymmetry of the thyroid gland was seen, but there was no evidence of a parathyroid abnormality. A planned left thyroid lobectomy and intraoperative PTH assay was converted intra-operatively to a near-total thyroidectomy and bilateral superior parathyroidectomy. Final pathological diagnoses were: (1) encapsulated papillary carcinoma, follicular variant, of the left lobe of the thyroid (greatest diameter 4.1 cm, with multifocal capsular invasion and at least 4 foci of vascular invasion); (2) two additional foci of papillary microcarcinoma, one in the left lobe and one in the isthmus; and (3) chief cell hyperplasia of the right and left superior parathyroid glands.