Diagnostic value of qualitative and quantitative variables in thyroid lesions

Abstract

Two hundred and thirty-three thyroid lesions were studied by fine needle aspiration (FNA) cytology using standard cytologic criteria available in the literature. These included 114 cases of nodular colloid goitre (NCG), 47 cases of Hashimoto's thyroiditis (HT), 12 follicular adenomas (FAd), five cases of subacute thyroiditis and three cases of thyrotoxicosis among the benign lesions. The malignant lesions seen were 30 cases of papillary carcinoma (PCa), 16 follicular carcinomas (FCa), three cases with double lesions, e.g. papillary carcinoma with coexisting NCG, and three of papillary carcinoma with HT. Emphasis was given to eight qualitative and quantitative (morphometric) variables in these various thyroid lesions. Cell measurements were done using a Visopan Lux projection microscope. The three qualitative variables included type of nuclear membrane (regular/irregular), type of nuclear chromatin and the presence or absence of conspicuous nucleoli. The quantitative variables studied were nuclear diameter, nuclear area, cytoplasmic diameter, cytoplasmic area & N/C ratio. Statistical analysis was performed in order to know whether the standard cytologic criteria used at FNA cytology in the literature (increased cellularity, microfollicles, increased N/C ratio, absence of significant haemosiderin-laden macrophages and scanty colloid) could differentiate a follicular adenoma from a follicular carcinoma. A statistical analysis was also performed to establish the utility of the qualitative and quantitative variables. The results showed that none of the standard cytologic criteria applied could differentiate follicular adenoma from a follicular carcinoma. With regard to qualitative variables, irregularity of nuclear membrane and presence of conspicuous nucleoli were most significant in papillary carcinoma, followed by follicular carcinoma, then by follicular adenoma; these features being hardly evident in nodular colloid goitre and Hashimoto's thyroiditis. A coarse nuclear chromatin was most significant in follicular carcinomas followed by follicular adenomas. It was less obvious in the benign conditions, but more prominent in Hashimoto's thyroiditis compared with a goitre. It was also not obvious in a papillary carcinoma. Of the quantitative variables, all measurements were greatest in PCa > FCa > FAd > NCG = HT. When differentiating follicular adenoma from follicular carcinoma the qualitative variables of significance were the presence or absence of nucleoli, the chromatin pattern and regularity/irregularity of nuclear membrane; the nuclear area was the most important feature among quantitative variables.

Role of morphometry in the cytological differentiation of benign and malignant thyroid lesions

“…Rout et al . [16] found similar results with nuclear area and mean nuclear diameter to be highest in papillary carcinoma than that in follicular carcinoma and follicular adenoma and least in nodular colloid goitre. Wright et al .…”

Digital image‐assisted quantitative nuclear analysis improves diagnostic accuracy of thyroid fine‐needle aspiration cytology

“…However, nearly all studies have used nuclear area as one of their indicators, and several have used some sort of measure of roundness/ovalness. In general, virtually all studies have found statistically significant differences in nuclear area (and many other nuclear features evaluated) between benign and PTC nuclei (Table ) . Many have reported sufficient overlap to limit the utility in clinical practice, but others have found that nuclear area, alone or in combination with other morphometric features, can achieve accuracy of 70% or greater .…”

Fluorescence lifetime of normal, benign, and malignant thyroid tissues

“…[1][2][3][4] Most of the surgeons rely upon gross inspection of size, hardness, and texture of the lesions to select thyroid tissues to send to pathologists for fast frozen section diagnosis during surgery. However, this method cannot effectively differentiate between benign and malignant follicular lesions.…”