Tumors of the parathyroid glands. Changes in clinical features and in noninvasive localization studies sensitivity

Primary hyperparathyroidism is the most common cause of hypercalcemia and 80-85% of the patients have parathyroid tumors. The purpose of this retrospective review was to analyse whether differences exist between patients with parathyroid tumors treated in the 1980s and 1990s. Between 1980-1997, 253 patients underwent initial surgical neck exploration for hyperfunctioning parathyroid tumors. Renal (polyuria, nocturia, renal colic due to lithiasis), rheumatologic (bone and joint pain), neurological (fatigue, memory loss, depression) and gastrointestinal (dyspepsia, anorexia, nausea) symptoms were recorded and main biochemical parameters were measured. In all patients one or more preoperative localization procedures were carried out prior to successful parathyroidectomy, and the confirmation of imaging findings was obtained after surgery. The patients were divided in two groups. Group A: 121 (47.8%) patients who underwent surgery from 1980-1989; Group B: 132 (52.2%) patients in whom parathyroidectomy was performed from 1990-1997. There were no differences (p=NS) between the two groups in average age, preoperative serum creatinine and intact-PTH levels. Symptoms were most common in Group A, and pre-operative serum calcium levels were significantly lower in Group B. Ultrasonography (n=191) sensitivity did not improve significantly (82.8% vs 82.9%), but positive predictive value (PPV) was higher (89.8% vs 96.0%). CT-scan (n=73) sensitivity was 79.2% and 82.6%, and PPV was 95.0% and 100% in Groups A and B, respectively. 201Tl/99mTc subtraction scintigraphy (n=111, Group A) was 84.6% sensitive (PPV=92.6%) whereas 99mTc-sestamibi scanning (n=90, Group B) was 85.1% sensitive (PPV=96.1%). In conclusion, the clinical features of parathyroid tumors has changed in the nineties and increasing asymptomatic pHPT rate has been found. Although sensitivity and PPV of preoperative localization procedures has improved moderately, at present noninvasive techniques may offer excellent results and should be used in all patients with suspected parathyroid tumors.