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

Abstract

Context:Thyroid nodules represent a common problem, with an estimated prevalence of 4–7%. Although fine needle aspiration cytology (FNAC) has been accepted as a first line diagnostic test, the rate of false negative reports of malignancy is still high. Nuclear morphometry is the measurement of nuclear parameters by image analysis. Image analysis can merge the advantages of morphologic interpretation with those of quantitative data.Aims:To evaluate the nuclear morphometric parameters in fine needle aspirates of thyroid lesions and to study its role in differentiating benign from malignant thyroid lesions.Material and Methods:The study included 19 benign and 16 malignant thyroid lesions. Image analysis was performed on Giemsa-stained FNAC slides by Nikon NIS-Elements Advanced Research software (Version 4.00). Nuclear morphometric parameters analyzed included nuclear size, shape, texture, and density parameters.Statistical Analysis:Normally distributed continuous variables were compared using the unpaired t-test for two groups and analysis of variance was used for three or more groups. Tukey or Tamhane's T2 multiple comparison test was used to assess the differences between the individual groups. Categorical variables were analyzed using the chi square test.Results and Conclusion:Five out of the six nuclear size parameters as well as all the texture and density parameters studied were significant in distinguishing between benign and malignant thyroid lesions (P < 0.05). Cut-off values were derived to differentiate between benign and malignant cases.

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

“…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 . The current study found relatively good distinction by nuclear area, albeit with limited overlap in cases with indefinite qualitative cytologic interpretations.…”

“…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 .…”

“…At least as early as 1980, several studies have evaluated morphometric analysis of thyroid cytology . The specific clinical question evaluated, the type of preparation, the exact set of parameters evaluated, and imaging and image analysis modalities have varied widely in these studies, making it challenging to compare studies or to draw clear conclusions about the effectiveness of these techniques . However, nearly all studies have used nuclear area as one of their indicators, and several have used some sort of measure of roundness/ovalness.…”

“…[29][30][31][32][33][34][35][36][37][38][39][40][41][42] 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. 31,32,34,35,41,42 The current study found relatively good distinction by nuclear area, albeit with limited overlap in cases with indefinite qualitative cytologic interpretations. Taken together, the current study and past literature support the utility of nuclear morphometry, especially nuclear area, as a useful tool to help with cytologic classification, but probably not as a stand-alone test, to distinguish PTC from benign on smears.…”

“…It follows that thyroid cytology could benefit from the implementation of a standardized, objective method to evaluate nuclear features to provide increased precision over the human eye to resolve difficult diagnoses. Over the last few decades, several studies have evaluated the use of cytomorphometry in categorizing thyroid lesions, with mixed results …”