MULTINODULAR GOITER OF THE THYROID MIMICKING MALIGNANCY - DIAGNOSTIC PITFALLS IN FINE-NEEDLE ASPIRATION BIOPSY

A case of multinodular goiter with multicentric papillary hyperplasia is presented with cytologic features suggestive of thyroid papillary c arcinoma. While the cytologic criteria for papillary thyroid carcinoma is well defined, occasional diagnostic difficulties can arise. Cytolo gically, the presence of focal papillary aggregates, the presence of a psammoma body within a background of copious colloid and scattered fo llicular cells led to diagnostic confusion. Histologically, the presen ce of secondary follicles in the papillae and protrusion of the papill ary structures into colloid lakes supported the diagnosis of goiter. I t is our opinion that most, if not all, of these difficulties can be c ircumvented by the incorporation of all major and some minor cytologic criteria for papillary carcinoma in the analysis of such lesions. Sin gle criteria for papillary carcinoma, either major or minor, is not su fficient.