Quantitative assessment of oxyphilic cell lesions of the thyroid gland on fine needle aspiration samples

OBJECTIVE: To assess the possible contribution by a multiparametric quantit ative approach to the cytologic diagnosis of oxyphilic cell (OC) thyroid le sions. STUDY DESIGN: Ten cases of chronic lymphocytic (Hashimoto) thyroiditis and 10 Modular goiters containing oxyphilic cells plus 20 cases of tumors subse quently classified as oxyphilic cell adenomas (10 cases) or oxyphilic cell well-differentiate carcinomas (10 cases) were evaluated. The study was perf ormed on May Grunwald-Giesma-stained smears for planimetric measur ments. T he same smears were destained and Feulgen restrained for densitometric meas urements. The latter were performed using static cytometry equipment measur ing 100 and 20-30 lymphocytes per case for the determination of integrated optical density (IOD). The following parameters were considered: nuclear ar ea, perimeter, maximum diameter, form ELL, form PE, IOD, 5c exceeding rate (5cER) and visual classification of histograms as euploid, polyploid and an euploid. RESULTS: Mean nuclear area of carcinomas was smaller than that of adenomas, goiter and thyroiditis. Nuclear area was larger in adenomas than in other benign lesions and carcinomas. All the other planimetric parameters were si milar in the lesions examined. Four carcinomas and three adenomas were aneu ploid, and all the rest were euploid. All the cases of thyroiditis and goit er were euploid or polyploid; four thyroiditis cases showed polyploid histo grams and 5cER values > I. CONCLUSION: Morphometric and densitometric procedures have a limited role i n the discrimination of OC lesions, but small nuclear area values may be us eful distinguishing OC carcinoma from other lesions. The role of densitomet ry seems even more limited because aneuploid histograms may be found among adenomas and carcinomas. Further studies ave needed to explain polyploidy a nd 5cER > 1 in Hashimoto thyroiditis.