Endocrine Abstracts

Background: Parathyroid carcinoma (PC) is rare, usually presenting with hyperparathyroidism and severe hypercalcemia. A standardized diagnostic, prognostic and therapeutic approach has not been provided yet and TNM staging algorithm is not universally accepted. Surgery is the first-choice treatment and is the only effective therapy to control hypercalcaemia. Chemo- or radio-therapy, local treatments or novel drugs should be reserved to selected cases.

Case Presentation: A 63-year-old man complained of progressive fatigue, abdominal pain and weight loss. Blood exams showed: calcium 15.6 mg/dl, PTH 1250 pg/ml, phosphorus 1.2 mg/dl. Profuse hydration, diuretics and zolendronate 4 mg once were given. A CT scan showed pancreatitis, portal thrombosis; kidney stones; multiple osteolytic lesions (brown tumours at histology). Neck ultrasound found a 39 mm round hypoechoic nodule posterior to the left inferior thyroid lobe, confirmed to be a parathyroid gland by MIBI scan. Heparin and antibiotics were given to contrast thrombosis and the infectious risk associated to pancreatitis. Parathyroid surgery was performed, including en bloc resection of left thyroid lobe. Histology documented a PC. Thyroid lobe was infiltrated, while cervical lymph nodes were not involved (pT2, N0 TNM/AJCC 8TH). After surgery, intraoperative PTH values dropped and calcium progressively normalized. During multidisciplinary discussion active surveillance was suggested, based on neck ultra-sound and biochemical evaluation, reserving further treatment in case of recurrence of disease. Six months after surgery there is no evidence of the disease.

Conclusions: We reported an unusual case of PC, associated with life-threatening hypercalcemia, pancreatitis, portal thrombosis, nephrolithiasis and brown tumours. The management of PC is very challenging. Multidisciplinary approach results pivotal and further studies will be needed to define a standardized treatment program for parathyroid cancer.