Abstract Introduction Parathyroid carcinoma is a rare endocrine disorder usually presented as severe primary hyperparathyroidism and skeletal complications. We present a case report of 52-year-old woman complaining from right arm pain, polyarthralgia and malaise. Work-up revealed right humeral mass later diagnosed as Brown tumor. On further assessment, she was having overt hypercalcemia, high parathyroid hormone (PTH), severe osteoporosis, and large left parathyroid mass. After controlling her medical situation conservatively, surgical resection of the parathyroid mass was done successfully and atypical parathyroid carcinoma confirmed. This case highlights the implications of early detection of severe hyperparathyroidism manifestations and the diagnostic obstacles in distinguishing benign from malignant parathyroid disease. Parathyroid carcinoma is very rare and accounts for less than 1% of cases of primary hyperthyroidism (1). It presents severe symptoms such as severe hypercalcemia, kidney stones, and skeletal manifestations ranging from osteitis fibrosa cystica to brown tumor (2). This is a rare case of parathyroid carcinoma presented as a brown tumor of the humerus, encouraging the urge for holistic endocrine evaluation in such an issue. Clinical Case A 52-year-old woman presented with right arm pain, polyarthralgia, and fatigue. Enlarging right humerus mass biopsied and revealed a brown tumor. There was no nephrolithiasis or gastro-intestinal manifestations. Physical examination: a thin built, depressed, pallor woman with non-specific dysmorphic facial features. Laboratory results: Calcium: 14. 5 mg, phosphate 1. 83 mg, PTH 510. 4 ng, vitamin D (25-OH) 30. 85ng, creatinine 0. 8 mg, creatinine clearance 68 mL/min/1. 73m2, Hb=11. 1gm, ESR 15 mm. Second sample blood advocate PTH markedly increased to 1406. 1ng, Calcium 14. 2 mg, PO42 1. 59 mg. Imaging: neck ultrasound revealed a hypoechoic mass behind the left lobe measure 40x36 mm without dot of foci. Neck and chest CT scan localized 42x36x26 mm hyperdense enhancing lesion inferior to left thyroid lobe, multiple lytic bone lesions in ribs and osteosclerosis at D8 vertebra. DXA scans show severe osteoporosis with T score: -5. 1 (L-Spine), -4. 3 (femoral neck), -8. 6 (Left radius). Medical treatment initiated to control the high calcium level and manage severe osteoporosis by hydration, starting zoledronic acid infusion protocol and preparing the patient for surgery. Neck dissection with mass excision was done by expert surgeon leading to normalization of calcium (8. 8mg) and a drop in PTH (221. 2ng) was achieved. Atypical parathyroid carcinoma with lympho-vascular and muscle invasion was confirmed by histopathological report. Conclusion A rare occurrence of parathyroid carcinoma has to be suspected for a case with extensive bone lesions and excess parathyroid secretion. Endocrine evaluation is corner stone to plan for precise diagnosis and management. Table 1: biochemical data of the patient with parathyroid carcinoma pre- and post-operatively.
Altemimi et al. (Thu,) studied this question.