A score based on microscopic criteria proposed for analysis of papillary carcinoma of the thyroid

Abstract

Morphologic examination is the gold standard for diagnosing papillary thyroid carcinoma (PTC). This diagnosis, especially for the follicular variant, may be variable even among experts. Our objective was to analyze the frequency of PTC microscopic criteria in a series of thyroid tumors including follicular adenoma (FA) and PTC to build a score which could constitute a novel way for microscopic analysis of such thyroid tumors. Sixty-six PTC and 66 FA were matched for age, sex, and thyroiditis. Two independent observers delineated the classical PTC microscopic criteria. PTC microscopic criteria were variably expressed in individual tumors. Under univariate analysis, all criteria were significantly more frequent in PTC than in FA (p<0.05). Under multivariate analysis, the most important criteria were: dark staining colloid >25%, nuclear grooves, enlarged nuclei, ovoid nuclei >5% of tumor cells, and lack of polarization. Using linear discriminant analysis, these five criteria allowed us to build a scaled score. The score proposed did not allow the making of a definite distinction between FA and PTC in routine practice. It represents the variety of microscopic presentations of FA and PTC on the basis of a statistical analysis and could help in further evaluation of immunohistochemical or molecular markers.

Scoring system for papillary thyroid carcinoma - a histopathological study

“…For these authors, the presence of nuclear pseudo inclusions was the less frequent finding among all tumours (54%). Similar results were also seen in a study conducted by Verhulst et al who stressed the importance of ovoid nucleus, enlarged nuclei, dark staining colloid, lack of polarisation, nuclear grooves in determining malignant status of the lesions [9].…”

“…Clearing is said when nucleus shows peripheral condensation of chromatin giving it vesicular appearance and nuclear grooving when nucleus folds into itself [9]. About 70% of PTC cases in our study showed clearing followed by 41% of cases showing grooving.…”

“…This score included seven criteria with specific weight: colloid <50% (0 when absent or 2 when present) + papillae >1% (0 when absent and 2 when present + nuclear crowding > 25% (0 when absent or 2 when present) + nuclear grooving >5% (0 when absent or 2 when present) + nuclear enalrgement >50% (0 when absent or 3 when present) + oval nucleus> 25% (0 when absent and 2 when present) + nuclear clearing >50% (0 when absent and 4 when present). The "gold standard" for the diagnosis of PTC still relies on microscopic features [9].…”

Nuclear Features in the Diagnosis of Follicular Variant of Papillary Thyroid Carcinoma—The Diagnostic Dilemma

“…According to Livolsi et al strict criteria for specific nuclear features comprising of ovoid nuclei, crowded nuclei, clear nuclei, intranuclear grooves and inclusions should be applied to diagnose FVPC [7]. They also observed that other favorable features included psammoma bodies and secondary features such as elongated irregularly shaped follicles, dark staining colloid, and multinucleated histiocytes in the lumen of the follicles [5].…”

“…Chan proposed criteria for the diagnosis of encapsulated FVPC which include clear nuclei, round to oval nuclei, crowded nuclei, intranuclear grooves, psammoma bodies and secondary features like irregular follicles, thick colloid and multinucleated histiocytes [1]. A scoring system was applied for the diagnosis of PTC by Verhulst et al who observed that follicular patterned PTC was at or below the threshold score [7].…”