Paratiroidni karcinom
Authors: Miletić Marija , Stojanović Miloš , Jovanović Milan , Nedeljković-Beleslin Biljana , Stojković Mirjana , Ćirić Jasmina , Žarković Miloš 
Published: July 2021

Parathyroid cancer (PC) is an uncommon malignant disease, with less than 1,000 cases reported in the literature since de Quervain first described it in 1904 as a non-functional metastatic cancer. With an estimated prevalence of 0.005% of all cancers, PC is the rarest endocrine cancer and accounts for only 0.5-5% of all cases of primary hyperparathyroidism (PHPT). The pathogenesis of PC is unknown. The etiology of PC is not clear and there is no evidence that PC is formed by the transformation of pre-existing parathyroid lesions. The aberrant profile of microRNA expression and methylation recently identified by PCR provides evidence that malignant forms of the parathyroid gland are different from benign lesions. PC may be sporadic or part of a genetic syndrome. Sporadic PC is most often associated with exposure to external radiation, and rarely with secondary and tertiary HPT due to chronic renal failure. The association of PC, synchronous or metachronous, with a history of PT gland hyperplasia, parathyroid adenoma (PA), or thyroid cancer with concomitant PA has also been reported. PC usually presents with indolent but persistent clinical symptoms; patients often show symptoms and complications of severe PHPT such as anxiety, depression, weakness, weight loss, bone and kidney disease, abdominal pain, nausea, pancreatitis, and peptic ulcer. In the investigation series, 50% of patients show manifestations of renal and bone pathology, including osteopenia, osteoporosis, osteoofibrosis, osteitis fibrosa cystica, subperiosteal resorption and pathological fractures. Renal disease manifests mainly as nephrolithiasis and renal failure with a prevalence of 56 and 84%, respectively. It has been observed that serum calcium levels are often higher than 3.5 mmol / l (as opposed to <2.8 mmol / l in benign disease), while serum PTH levels are usually 3 to 10 times higher than the upper normal limit (benign PT). disease may show a more moderate increase), although there is no agreed threshold for PTH and serum calcium levels to define PT malignancy. As with benign disease, visualization is necessary for tumor localization, but it cannot reliably distinguish benign from malignant disease. Several imaging methods, most often a combination of MIBI and ultrasound examination of the neck, increase diagnostic sensitivity and accuracy. Some ultrasound features can predict malignancy and help identify pathological lymph nodes or invasion of nearby structures: a size> 3 cm should cause PC suspicion. Intraoperative findings suspected on PC have been described. In most series, the median maximum PC diameter is 3-3.5 cm (<10% greater than 4 cm), compared to approximately 1.5 cm for PA. 21% of cancers have been reported to have a cystic component. No universal system of clinical and pathological stages for PC has been adopted, because there is no correlation between tumor diameter or lymph node status with survival, and the disease is very rarely diagnosed preoperatively or even intraoperatively. Schulte et al proposed a system of determination based on two classification schemes, a differentiated classification as within the TNM classification and a high-risk / low-risk classification that appears to show significant prediction power for survival or relapse. Historically, almost 96% of PC patients have been treated surgically, and surgery is the only effective therapy to control hypercalcemia, both at initial resection and at the time of metastasis recurrence. Optimal treatment of hypercalcemia is important before surgery. A patient with long unrecognized primary hyperparathyroidism despite the manifestation of classic signs and symptoms of the disease: bilateral nephrocalculosis, hypertension, increased thirst, constipation, depression, pain in the lumbar spine is presented. Upon admission to the Clinic for endocrinology and Metabolic Diseases, biochemical analyzes were performed: eGFR: 46 ml / min / 1.73 m2, calcium: 3.34mmol / l [2.15-2.65], calcium, ionized: 1.89mmol / l [1.15-1.35], phosphorus: 0.74 mmol / l [0.8 - 1.55], magnesium: 0.72 mmol / l, PTH 1276 ng / l, vitamin D 14.2 nmol / l. After emergency therapy of hypercalcemia with bisphosphonates i.v., the patient was referred for surgical treatment due to the fulfillment of operative criteria. extraction of the upper right PT gland was performed, and histopathological findings indicated parathyroid cancer.