Endocrine Abstracts

Blackground: Parathyroid carcinoma is a malignant neoplasm affecting 0.5 to 5.0% of all patients suffering from primary hyperparathyroidism. This cancer continues to cause challenges for diagnosis and treatment because of its rarity, overlapping features with benign parathyroid disease.

Case report: 50 years-old-woman, without relevant previous history. She begins to present asthenia, weakness of lower limbs, arthralgias, cramps and appearance of a painful tumor but with progressive upgrowth at the level of the left tibial tuberosity since one year ago. Physical examination: blood pressure 100/54 mm/Hg, 55 kg, 166 cm BMI 19.9 kg/m², nodule in left thyroid lobe and painful tumor of 5×3 cm on palpation in left anterior tuberosity, atrophy muscular and no presence of edema in lower limbs. The rest of the exploration without findings. Blood test: Hb 12.5 g/dl, Ca 14 mg/dl (VN<10), P 1.8 mg/dl (VN >2.7), Mg 2.3 mg/dl, albumin 3.9 dl/l, 15 OH calcitriol 22.8 ng/ml (VN>30), PTH 1174 pg/ml (VN<65). Urine test: calcium / creatinine index 0.3 mg/mg. In thyroid ultrasound we observed on the lower pole of the left thyroid lobe an hypoechogenic and heterogeneous nodule of lobulated foci, predominantly solid but with a superior cystic, vascularized component, appearing to present a plane of separation with the thyroid gland with size 16.5×15×38 mm. Suggestive of parathyroid injury and whose location it was also confirmed by Tc99 m MIBI scintigraphy. The biopsy of the tibial tumor presents pathological anatomy compatible with brown tumor. Densitometry with osteoporosis in the lumbar spine T −2,6. In the surgical treatment, a left hemithyroidectomy was performed, removal of the two left parathyroid glands and ipsilateral lymph node dissection. Pathological anatomy suggestive of 2.5 cm parathyroid carcinoma infiltrating thyroid and focally adjacent fat. Contact the surgical edge. Postoperative PTH level, performed on the second day of surgery, was 95 pg/mL and calcium levels within normal. At hospital discharge we left her calcium supplements and alendronic acid to avoid hungry bone syndrome and treat osteoporosis. Monitoring should be done every 3 months with clinical examination and calcium levels during the first 3 years.

Conclusion: We observed that patients with parathyroid carcinoma are more likely to have symptoms than adenomas: appearance of neck mass, bone and kidney disease, elevated levels of calcium and PTH. When we have an early diagnosis and an early surgery, the percentage of survival can reach 67% in 10 years.