Angiography effectively supports the diagnosis of hepatic metastases in medullary thyroid carcinoma

BACKGROUND. Medullary thyroid carcinoma (MTC) belongs in the group of neuro endocrine tumors with early lymphatic and hepatic dissemination. A high rat e of undetectable metastases is hypothesized to be responsible for the freq uent mismatch between the apparent relatively small tumor burden and the el evated plasma tumor marker level. METHODS. Thirty-six MTC patients with residual/recurrent biochemical signs (elevated basal calcitonin level) and/or characteristic general symptoms (d iarrhea and/or flushing) were systematically examined by conventional radio logy, whole-body F-18-deoxyglucose positron emission tomography (PET), dyna mic liver computed tomography and magnetic resonance imaging, and hepatic a ngiography. RESULTS. Conventional diagnostic imaging revealed lymph node (LN) involveme nt in the cervical, mediastinal, supraclavicular, and axillary regions (16 cases), and multiple pulmonary (3 cases), bony (1 solitary and 1 multiple c ase), and breast (1 case) metastases. F-18-deoxyglucose PET identified all these extralymphatic metastatic lesions (except 2 cases with multiple pulmo nary metastases), and also supradiaphragmatic LN involvement in 34 (94%) pa tients. In 32 (89%) cases, multiple small (generally less than or equal to 1 cm) hypervascular, hepatic metastases undetectable by other imaging metho ds were localized angiographically. Of the 23 original pathologic specimens investigated, 18 (78%) exhibited LN involvement. The smallest primary tumo r in patients with hepatic metastases was 1 cm. CONCLUSIONS. Hepatic angiography is recommended for primary staging in MTC patients with a primary tumor measuring 1 cm or larger, and/or pathological ly proven LN involvement, and also during restaging for suspected recurrenc es to avoid unnecessary extensive surgical LN dissection in the neck and me diastinum. Cancer 2001;91:2084-95. (C) 2001 American Cancer Society.