THYROID-CANCER DETECTED BY ULTRASOUND-GUIDED FINE-NEEDLE ASPIRATION BIOPSY

A greater percentage of thyroid cancers can be detected by ultrasound- guided fine-needle aspiration biopsy (UG-FNAB) than by ordinary FNAB. A group of 678 patients were selected sequentially as having been diag nosed with benign nodules by the conventional FNAB method. We reexamin ed these patients by UG-FNAB and investigated the types of thyroid can cer that were missed by the conventional FNAB. Of the 678 patients dia gnosed with benign nodules (using conventional FNAB), 571 (84.2%) demo nstrated the same diagnosis when UG-FNAB was used. The remaining 107 p atients (15.8%) studied were suspected of having a malignancy after UG -FNAB had been performed. Surgical specimen histology proved thyroid c ancer in 99 of the 107 patients: 93 had papillary carcinoma, 4 had fol licular carcinoma, 1 had medullary carcinoma and 1 had anaplastic carc inoma. Two drawbacks were noted when conventional FNAB was used: (1) c ancer lesions difficult to palpate (n = 55) (e.g., small cancers with or without benign lesions or cancers associated with Hashimoto's thyro iditis or Graves' disease); and (2) palpable cancers with insufficient cell material for analysis (n = 44) (e.g., cystic carcinoma and cance rs,vith calcified lesions. UG-FNAB is a powerful technique for detecti ng microcancers, cystic carcinomas, cancers associated with benign nod ules, Hashimoto's thyroiditis, or coarse calcifications.