Parathyroid carcinoma: A rare case with mandible brown tumor

Abstract

5610 Background: Parathyroid carcinoma (PC) constitutes less than 1% of primary hyperparathyroidism. Prior radiation to neck, chronic renal failure and genetic factors play roles. The m/f is one. The mean age is 40. In half a palpable cervical mass is evident. Serum calcium levels are >14 mg/dl. Methods: A 21-year-old man with right sided non-mobile 1X1 cm mandible bulging without tenderness came to the TM center. Other presentations include fatigue, recent weight loss, hoarseness, polydipsia, polyuria, hematuria, recurrent renal stones and constipation - diarrhea. In mandible biopsy brown tumor was confirmed. In x-ray ground glass appearance of the skull and in 99mTc-MDP, Tc absorption was low in mandible. Serum Ca level was more than 15.4 mg/dl. In cervical sonography, a hypoecho area with suspicious of parathyroid adenoma (PA) was detected. During operation, a capsular mass with attachment to the surrounding tissue was excised. In pathology PC was detected and en bloc resection was performed. Hypercalcemia was controlled. During a two-year follow up, there was no evidence of tumor recurrence and/or hypercalcemia. Results: PC is a slowly progressive disease with frequent recurrence and late local metastasis. The combinations of young age, palpable neck mass, concomitant renal and skeletal disease, and extremely high iPTH level in PTH-dependent hypercalcemia is highly suggestive of PC. Etiologically deletion of q13 of chromosome 11 and loss of tumor suppressor genes RB and BRCA2 were recognized. Clinical manifestations are mainly due to hypercalcemia per se. Diagnosis is based on lymph node or distant metastasis, capsular or vascular invasion, presence of fibrotic networks or frequent mitosis. Early surgery with en bloc resection is the only potentially curative treatment. Bisphosphonates, calcitonin, dacarbazine and in-situ alcohol instillation is advocated. The 5-year survival is between 50–85%. Conclusions: This unique case of PC in attention to the brown tumor in mandible is the second worldwide. Second operation was performed due to lack of attention of rare causes of hyperparathyroidism. Comprehensive multidisciplinary approach with surgery, radiation therapy, and medical treatment for hypercalcemia is needed to optimize patient outcome. No significant financial relationships to disclose.