175 Hyperfunctioning Cystic Parathyroid Glands: CT and Sonographic Findings Adrian G. Krudy1 John L. Doppman1 Thomas H. Shawker1 Allen M. Spiegel2 Stephen J. Marx2 Jeffrey Norton3 Marcus Schaaf4 Morton L. Moss5 Michael A. Weiss5 Stephen H. Schachner Four functioning cystic parathyroid glands were evaluated with computed tomography (CT) and sonography in four patients, only one of whom had prior surgery. Sonography demonstrated solid lesions of decreased echogenicity with fluid-filled cavities near the lower thyroid poles or in the posterosuperior mediastinum. On CT the cystic parts of the lesions were of low attenuation (1-44 H), often with a well defined wall that was better demonstrated after intravenous contrast administration. Fine-needle aspiration biopsy of two of the cystic parathyroids revealed elevated parathyroid hormone levels. These lesions probably represent degenerating adenomas rather than true parathyroid cysts. While the CT and sonographic findings are nonspecific, the diagnosis of a cystic parathyroid should be entertained when a fluid-filled lesion is encountered in the neck of a patient with or without hypercalcemia. The diagnosis may be confirmed by assay of parathyroid hormone from the fluid aspirate. Abnormally enlarged parathyroid glands can be depicted by either computed tomographic (CT) scanning or sonography, and their appearance has been well described [1 -1 2]. Cystic parathyroid glands, whetherfunctioning or nonfunctioning, are less common [1 3] and have been described in several surgical reports [1 4- 1 7]. However, there are few reports of parathyroid cysts in the radiologic literature [1 8]. We present the CT and sonographic appearance of four functioning cystic parathyroid glands in patients with hyperparathyroidism. (Two of the four patients, cases 3 and 4, were included in series reported previously [8, 9].) Case Reports Case 1 Received June 6, 1983; accepted after revision August 26, 1983. 1Diagnostic Radiology Department, Clinical Con- ter, National Institutes of Health, Bethesda, MD 20205. Address reprint requests to A. G. Krudy (Bldg. 10, Room 6S211). 2 Metabolic Diseases Branch, National Institute of Arthritis, Diabetes, and Digestive and Kidney Diseases, Bethesda, MD 20205. 3 Surgery Branch, National Cancer Institute, Be- thesda, MD 20205. 4 Kyle Metabolic unit, Walter Reed Army Medical Center, Washington. DC 20012. 5 Department of Radiology, Commonwealth Hospital, Fairfax, VA 22030. 6 Section on Endocrinology, Fairfax Hospital, Falls Church, VA 22046. AJR 142:175-178, January 1984 o361-8o3x/84/1421-0175 C American Roentgen Ray Society An asymptomatic 63-year-old man had had hypercalcemia for several years, discovered by routine biochemical screening. There was no history of head and neck radiation nor family history of parathyroid disease. At admission no masses were palpated in the neck. Serum calcium was elevated to 1 2.3 mg/dl (normal, 8.5-1 1); serum phosphorus was 2.8 mg/dl (normal, 2.5-4.5). The 24-hr urine calcium was elevated. C terminal assay for serum parathy- reid hormone was elevated. A CT scan of the neck revealed a 3 x 1 .6 cm, partly cystic, partly solid mass in the right neck behind the right thyroid lobe (fig. 1). The cystic part of the lesion had an attenuation of 1 2-1 6 H and the solid component 74 H. A partly cystic parathyroid gland about 1 .7 cm in diameter was removed at surgery. Pathologic examination revealed a cystic oxyphilic parathyroid adenoma. Serum chemistries returned to normal after surgery. Case 2 A 73-year-old woman had a 21 -year history of multiple renal calculi and a 5-year history of hypercalcemia. Previous analysis of a stone indicated 90% calcium oxalate and 3% calcium oxalate monohydrate. There was no family history of parathyroid disease. On admission a 1 .5 cm, nontender nodule was palpated in the right lower pole of the thyroid. Serum calcium was 1 1 .8 mg/dI and serum parathyroid hormone was elevated. Alkaline phosphatase was Downloaded from www.ajronline.org by 3.92.57.205 on 05/21/20 from IP address 3.92.57.205. Copyright ARRS. For personal use only; all rights reserved