A euthyroid 72-year-old woman (TSH 1.1 mU/l) was referred to our institution for second-reading diagnostics. A small (maximum diameter 9 mm), hypoechoic nodule with central macrocalcification had been incidentally found within the thyroid. 99m Tc-PT scintigraphy had shown normal uptake with moderate maxima (right . left) in the upper parts of both thyroid lobes but no sign of hypofunctionality (Fig. 1) . The basal calcitonin level, however, was 123.0 pg/ml and therefore a medullary thyroid cancer was suspected.