parathyroid carcinoma is a very rare cause of primary hyperparathyroidism in children . in adults ,
the incidence is 1 to 5% , but in children , the incidence is not exactly known .
several articles have reported sporadic cases of parathyroid carcinoma occurring in pediatric patients [ 2 - 7 ] .
this patient is the eighth reported case of parathyroid carcinoma occurring in a child under the age of 16 years .
a previously healthy 13-year - old girl was admitted to our thyroid department for an asymptomatic palpable thyroid mass .
a 4 cm hard mass was palpable in the right lobe of the thyroid gland .
her total serum calcium was 12.0 mg / dl ( normal , 7.8 to 10 mg / dl ) , ionized calcium 1.52 mm / l ( normal , 0.96 to 1.4 mm / l ) , phosphorus 2.6 mg / dl ( normal , 2.9 to 4.3 mg / dl ) , alkaline phosphatase 2,700 iu / l ( normal , 25 to 100 iu / l ) , intact parathyroid hormone ( ipth ) level was 8,368 pg / ml ( normal , 15 to 65 pg / ml ) .
ultrasonography of the neck showed a 4 cm multifocal cystic mass in the right thyroid gland ( fig .
a 35  30  20 mm firm oval tumor was found behind and adherent to the right lobe of the thyroid gland .
an en bloc resection of the tumor , along the right lobe of the thyroid gland was performed and the central lymph node was removed .
the tumor weighed 22 g. on section it appeared grayish - yellow while histologically there were capsular , vascular and perineural invasion ( fig .
the patient underwent a chest computed tomography ( ct ) scan to evaluate for metastasis . on chest
ct scan , multiple scattered subpleural nodules in both lower lung lobes were found and we considered them to be benign nodules such as an inflammatory granuloma rather than metastases .
the total serum calcium and ipth levels decreased to 8.4 mg / dl and 49.48 pg / ml on the first postoperative day , and was 9.9 mg / dl , 70.99 pg / ml two weeks , respectively .
six months postoperatively , her calcium and parathyroid hormone levels increased to 9.7 mg / dl and 297.8 pg / ml , respectively . on chest
ct scan , 7 small well - defined nodules suspicious for hematogenous parathyroid carcinoma metastases appeared with increasing size bilaterally compared to her previous ct scan ( fig .
3 ) . bilateral lung wedge resection was performed by a thoracic surgeon and 8 metastatic nodules were removed .
six months later , her ct scan showed new multiple metastatic nodules in both lungs .
four years later , her calcium and parathyroid hormone levels increased to 12.4 mg / dl and 191.5 pg / ml .
bisphosphonates were used to control hypercalcemia , but improvement in bone mineral density was noted with no other symptoms present .
it usually occurs in middle - aged individuals during their third through sixth decades of life . until now
, only 6 cases have been reported of parathyroid carcinoma occurring within the age range of 8 to 15 years [ 2 - 7 ] .
the clinical manifestations of parathyroid carcinoma in pediatric patients include palpable neck mass , bone pain , weakness , pancreatitis , malaise , polyuria , polydipsia , nausea , and vomiting .
a common clinical manifestation among the reported patients was a palpable neck mass , as seen in our patient .
most patients reported had severe hypercalcemia , with total serum calcium levels greater than 13 mg / dl without metastasis .
although there were bilateral lung metastases , in our patient , the total calcium level only mildly increased , but markedly elevated levels of pth and alkaline phosphatase were seen .
a palpable neck mass with hypercalcemia and markedly elevated levels of pth in pediatric patients should raise concern for parathyroid carcinoma .
the histologic criteria for parathyroid carcinoma includes a trabecular pattern , mitotic figures , and capsular and blood vessel invasion .
since it is usually not diagnosed preoperatively , it is important that parathyroid carcinoma be considered intraoperatively when the tumor adheres to surrounding structures , including the thyroid gland , strap muscles , and the recurrent laryngeal nerve . if it is suspicious , aggressive treatment should be considered .
surgery is the most important treatment for parathyroid carcinoma . en bloc resection with ipsilateral thyroid lobectomy
, avoiding rupture of the tumor capsule and spillage of tumor cell , at the first operation is the only curative treatment , and aggressive initial treatment is important to reduce local recurrence and improve the prognosis .
considering that there have been several reports of metastasis and recurrence after operation , total calcium and ipth levels should be monitored frequently . in our patient ,
the lung nodule on chest ct scan was considered to be a benign nodule because of normalization of total calcium and ipth after operation . however , after 6 months , metastatic parathyroid carcinoma was suspected because of increased total calcium and ipth levels with increased nodule size on follow - up ct scan .
recurrence and systemic metastases occurs in up to 52% of patients with parathyroid carcinoma . like our patient 's case ,
the lung is the most frequent site of metastases   while metastases to the bone , liver and brain can also occur . when metastases are found , metastasectomy is recommended to reduce hypercalcemia because severe hypercalcemia and its metabolic complications are associated with increased mortality . since the growth rate of parathyroid carcinoma is slow ,
chemotherapeutic agents , adjuvant radiotherapy and medical management , including calcitonin , mithramycin , and bisphosphonates , may be used for patients with uncontrollable hypercalcemia with unresectable or widespread metastatic disease . however ,
preoperatively , if there is severe hypercalcemia , elevated parathyroid hormone levels and palpable neck mass in a pediatric patient , parathyroid carcinoma should be suspected . en
hypercalcemia related metabolic complications are associated with increased mortality . even if metastasis or recurrence is detected
, aggressive resection of the metastatic parathyroid carcinoma is the most effective treatment to control hypercalcemia and improve survival .
 parathyroid carcinoma is a rare disease in pediatric patients . we present a case of a 13-year - old girl who presented to the thyroid department for an asymptomatic palpable neck mass for 1 year . 
 the high levels of calcium , ionized calcium , and parathyroid hormone level along with parathyroid scintigraphy studies suggested primary hyperparathyroidism . 
 parathyroid carcinoma was confirmed by biopsy and pathologic examination after resection . 
 six months postoperatively , persistent hypercalcemia and multiple lung metastases were found on computed tomography . 
 bilateral lung wedge resection was performed . en 
 bloc resection for primary parathyroid carcinoma and aggressive resection of metastatic disease is the most effective treatment to control hypercalcemia . 
INTRODUCTION
CASE REPORT
DISCUSSION