Computer-assisted cell morphometry and ploidy analysis in the assessment of thyroid follicular neoplasms

Conventional cytology cannot discriminate between benign and malignant foll icular neoplasms. Our study evaluated the diagnostic role of computer-assis ted image analysis in the presurgical assessment of thyroid follicular neop lasms. Fifty-eight patients (14 males, 44 females, age range, 45-75 years) who underwent surgery for cytologic diagnosis of thyroid follicular neoplas m were studied. All patients were first evaluated on clinical grounds and a ssigned a high/low suspicion of malignancy on the basis of gender, age, and nodule size. Cell image analysis was subsequently performed using a Cytome trica BYK Gulden microscope image processor on Feulgen-stained thyroid cyto logic smears. A different population of 50 benign and 50 malignant, histolo gically evaluated nodules was studied in order to establish image analysis criteria suggestive of thyroid malignancy. Ploidy histogram, proliferation index (PI), nuclear area coefficient of variation (NACV), and anisocariosis ratio (AR) were studied. Thyroid cancer was diagnosed in 16 of 58 follicul ar neoplasms. Only 7 of these lesions were clinically suspicious (43.7%), w hereas 14 of 16 (87.5%) malignant tumors were identified by image analysis. Positive and negative predictive values of image analysis versus clinical evaluation were 46.6% versus 30.4% and 92.8% versus 74.3%, respectively. Th e distribution of ploidy pattern was different in benign versus malignant f ollicular neoplasms (chi (2) 8.25, p = 0.016), malignant lesions showing an increased frequency of heteroclonal aneuploid DNA content (37.5% vs. 7.1%) . Increased PI (mean +/- standard deviation (SD) = 11.3 +/- 5.7 vs. 7.1 +/- 6.1; p < 0.01) and NACV (mean +/- SD = 25.28 +/- 1.89 vs. 20.14 +/- 0.91; p < 0.01) levels were also observed in malignant follicular neoplasms. In c onclusion, computer-assisted image analysis may profitably support clinical evaluation in the assessment of thyroid follicular neoplasms.