Clinical features and outcome of sporadic medullary thyroid carcinoma
Paula Sánchez Sobrino, Concepción Páramo Fernández, Beatriz Mantiñán Gil, Alberto Pérez Pedrosa, Regina Palmeiro Carballeiro, Inés Seoane Cruz & Ricardo V García-Mayor
Introduction: Medullary thyroid carcinoma (MTC) is a neuroendocrine tumour that arises from c cells of the thyroid gland and accounts for less than 8% of thyroid neoplasms. Some are familiar (MEN 2 syndrome) but most are sporadic. Genetic tests have improved the outcome in hereditary forms, but survival in sporadic MTC has not increased in last years. In most patients with sporadic MTC the disease has already metastasized at the time of diagnosis.
Objective: To evaluate the clinical-pathological characteristics and outcome of our patients with sporadic MTC.
Patients and methods: We recruited 17 patients with confirmed sporadic MTC between 1994 and 2009 after excluding those with familiar history, RET mutation or other features associated to MEN 2.
Results: A total of 17 patients with sporadic MTC were studied, 10 women, mean age 47.5±14.99 years old (range from 16 to 68). All of them had thyroid nodules; 81.8% solitary nodule (72.7% bigger than 3 cm) and 100% had radiologic findings of malignancy. Approximately a half of the patients complained about compressive symptoms such as dyspnea, dysphagia or hoarseness. Three patients had palpable cervical lymphadenopathies. Cytology by fine needle aspiration (FNA) showed an accurate diagnosis in only 35.7% of cases. More than 50% were diagnosed at stages III or IV. Of 7 patients in early stage 4 achieved clinical remission and only 2 of the 10 patients at advanced stage.
Conclusion: Sporadic MTC is a rare malignancy that remains unnoticed until advanced stages conditioning a worse prognosis. It appears clinically in the form of a thyroid nodule with objective data of malignancy at imaging techniques and local compressive symptoms in most cases. In our experience FNA has had low sensibility for diagnosis.