FOLLICULAR NEOPLASMS OF THE THYROID - DECISION TREE APPROACH USING MORPHOLOGIC AND MORPHOMETRIC PARAMETERS

OBJECTIVE: Fine needle aspiration of the thyroid is limited in differe ntiating hyperplastic nodular goiters from true follicular neoplasms a nd in separating follicular adenomas from follicular carcinomas. The p resent study was done to evaluate ifa panel of morphologic and morphom etric parameters of the thyroid and ploidy status, either alone or in combination, would help differentiate hyperplastic nodular goiters fro m follicular adenomas and carcinomas. STUDY DESIGN: Fine needle aspira tion smears of 75 cases classified as follicular neoplasms of the thyr oid were studied for morphologic (cellularity, colloid and cellular pa tterns) and morphometric parameters (nuclear diameters and nucleoli). RESULTS: Of the large number of parameters utilized in this study, onl y two of the cellular patterns (honeycomb and single dispersed) and th e average maximum nuclear diameter showed trends in differentiating th ese lesions. CONCLUSION: Based on these patterns and nuclear diameter (9 mu m), we developed a decision tree classification that separated t he benign from malignant lesions (follicular carcinomas) with a sensit ivity and specificity of 92.8% and 57.4%, respectively.