Endocrine Abstracts

Introduction: Medullary thyroid cancer (MTC) is a neuroendocrine tumor of the parafollicular or C cells of the thyroid gland. While thyroid cancer is increasingly common worldwide, MTC still has a low incidence. We present a case of a seventy-one-years-old woman who presented in our unit after an axillary adenopathy biopsy which tested sparsely positive for KeratinPan, CK7, CEA, TTF1, Chromogranin, Snaptophysin and calcitonin, focal positive for EMA, PAX8, Ki67 30%. Also multiple liver, lung and supraclavicular, axillary tumors were described, the largest supraclavicular adenopathy was 59/35 mm. The evaluation in our clinic, in august described a large thyroid gland with multiple nodules described in both lobes, the largest of them was bulking in the mediastinum, reaching the aortic cross and measured 3.93/3.5 cm, imprecisely delimited from the surrounding tissue, with multiple calcifications and high vascularization, as well as multiple large latherocervical lymph nodes. Calcitonin (177000 pg/ml) and CEA (305 ng/ml) where also elevated suggestive for MTC. The additional evaluation revealed a severe hypokalemia, and high cortisol and ACTH values unsuppressed after high dose Dexamethasone, suggesting associated Cushing. The patient underwent total thyroidectomy with large resection of involved lymph node compartments, were the TNM classification was pT3b pN1b stage IV B. After hemodynamic rebalancing, and testing of the RET mutation, the patient was started on TKI, Vandetanib 200 mg/day. During one year of treatment with TKI, the patient remained stable, without any new lesions observed on the evolutive CT findings. Biochemical findings revealed an initial lowering of Calcitonin and CEA, then the values started to increase, the patient started developing cognitive impairment and dizziness. The particularity of this case high stage MTC associated with paraneoplastic Cushing make more insidious the progress and worsen prognosis of the disease, by being difficult to predict the effects of bilateral adrenalectomy, chemoembolization of liver metastases or radiofrequency ablation for lung metastases, especially in a patient with clinical decline (diarrhea, cognitive impairment, muscular weakness, dizziness which could be an indicator of disease progression-brain metastases).

Conclusions: The therapeutic approach is always a challenge in metastasized cancer, patients benefitting nowadays from the tyrosine kinase inhibitors, especially RET inhibitors, Vandetanib. The presence of distant metastases, and calcitonin doubling time are the most important prognostic factors in determining survival.