Solitary cold thyroid nodules -- a correlation of fine needle aspiration cytology with pentavalent technetium DMSA scanning and radionuclide perfusion scanning.

Twenty-five patients with solitary cold thyroid nodules (SCN) were studied by fine needle aspiration (FNA) cytology, radionuclide perfusion scanning (RPS) and pentavalent technetium dimercaptosuccinic acid (99m Tc DMSA) scanning, with an aim to distinguish neoplastic from non-neoplastic nodules. All the patients were operated upon and the nodules were subjected to histopathological examination. 13 of the 25 nodules (52%) were malignant (7 papillary carcinomas, 3 medullary thyroid carcinomas and 1 each of follicular carcinoma, insular carcinoma and clinically anaplastic thyroid tumour). The specificity of DMSA scanning and FNA cytology were 100% and that of RPS 60%. The sensitivity of RPS and DMSA scanning were 80% and 20% and that of FNA cytology (using a broad definition of test-positivity), 100%. Additionally, FNA cytology could morphologically type the majority of neoplasms.