Prognostic value of morphometry in papillary thyroid carcinoma

Papillary Thyroid Carcinoma and Related Thyroid Neoplastic Lesions: A Light Microscopic Study with Emphasis on Nuclear Changes

A total of 187 thyroid lesions consisting of 2 cases of Grave's disease, 21 cases of multinodular goiter, 40 follicular adenomas and 124 low-grade papillary thyroid carcinomas were studied to identify intermediate neoplastic lesions in the spectrum of nuclear changes between benign reactive thyroid follicles and low-grade thyroid papillary carcinoma. The lesions were examined and classified on the basis of the following nuclear features: fine chromatin seen in the thyroid papillary carcinomas and coarse chromatin seen in follicular carcinomas. Cases with Hürthle cell changes were excluded from the study. Cases with nuclei containing coarse chromatin were classified in the group of follicular adenomas with a coarse chromatin pattern. The neoplastic thyroid lesions containing fine chromatin showed a spectrum of nuclear changes ranging between reactive follicular lesions and papillary thyroid carcinoma with lymph node metastasis. Such lesions were classified as follicular adenomas with a fine chromatin pattern. The nuclei of these lesions were graded into mild to marked "nuclear atypia with a fine chromatin pattern". The degree of atypia depended on the degree and extent of nuclear changes. Encapsulated follicular adenomas with a fine chromatin pattern and with mild atypia (11 cases), moderate atypia (13 cases), marked atypia (27 cases), and encapsulated or nonencapsulated papillary thyroid carcinoma were characterized by uniform nuclei; with mild, moderate and marked nuclear atypia in less than 2/3 of the cell population and marked nuclear atypia in more than 2/3 of the cell population; and measuring 5.4-6.3, 6.0-7.2, 6.3-9 and 7.2-10 microns in diameter, respectively. Follow-up of cases of papillary thyroid carcinoma fulfilling the above criteria showed lymph node metastasis in 33% of cases, whereas follicular adenomas with a fine chromatin pattern, including cases originally diagnosed as papillary carcinoma, showed no evidence of lymph node or distant metastasis in a follow-up period of 30 months to 15 years. In the thyroid tissue surrounding papillary thyroid carcinoma or encapsulated follicular adenoma with a fine chromatin pattern and marked atypia, adenomatous nodules with a fine chromatin pattern and with low-grade nuclear atypia were identified. The adenomatous nodules with a fine chromatin pattern and with mild, moderate and marked atypia showed architectural, cytoplasmic and nuclear features similar to those of follicular adenoma with a fine chromatin pattern of the same grade. Of interest, a large number of cases of follicular adenoma with a fine chromatin pattern had areas with features of follicular adenoma with a coarse chromatin pattern.

On the concept of objectivity in digital image analysis in pathology

AIMS

The term 'objective' connotes a method that is based on facts and not influenced by personal opinions, perception or emotion. One often reads in the biomedical literature claims of objectivity for methods that use digital image analysis applied to histology. Since objective assessment of histology would represent a huge leap forward in scientific measurement and clinical diagnosis, such claims should be substantiated by strong evidence. This paper takes a selective look at the literature on image analysis to assess the definition of objectivity in image analysis and asks whether such a claim is ever justified.

METHODS

First, a brief background on the basic science of image analysis in histology details some of the controversies and opinions in the field. Then, a literature review of a subset of papers pertaining to image analysis in histology (with claims of objectivity) is conducted to determine what evidence exists for objectivity in these methods.

RESULTS

It was found that image analysis may have many benefits (speed, indefatigability, standardisation, etc.). However, algorithms are devised and implemented by human beings who make subjective decisions at each stage of the algorithm design and implementation process. Thus, image analysis methods can be seen as deterministic processes which 'objectively' implement the subjective decisions of the programmer. This indicates that 'inter-observer' variation in image analysis is equivalent to 'inter-algorithm' variation (which is rarely studied) and that a single computer algorithm's repeatability is of lesser importance than the repeatability of the image analysis method as a whole (including the block, slide and field selection and the method of tissue processing).

CONCLUSION

Repeatability and automaticity must not be confused with objectivity, but a lack of objectivity does not imply a lack of utility. Unless specific evidence of objectivity is provided, editors should insist that claims of objectivity in image analysis papers be either removed or justified prior to publication.

Absence of prognostic value of nuclear shape factor analysis in colorectal carcinoma: relevance of interobserver and intraobserver variability

PURPOSE

Several retrospective studies, including our previous investigation, have shown a prognostic value of nuclear shape factor in colorectal carcinomas. This prospective study was designed to assess the reliability of nuclear shape factor determined by nuclear morphometry and to confirm its prognostic value.

METHODS

Ninety-eight patients who underwent colorectal carcinoma resection were prospectively enrolled. Measurement of nuclear shape factor was performed by using a computer-based image analysis system. Nuclear shape factor was defined as the degree of circularity of the nucleus (1.0 for a perfect circle and <1.0 for any other elliptical shape). The prognostic impact of nuclear shape factor on ten-year survival and the intraobserver and interobserver agreement were assessed.

RESULTS

The nuclear shape factor mean values by American Joint Committee on Cancer stage were: 0.73 (0.07) in Stage I, 0.74 (0.06) in Stage II, and 0.75 (0.05) in Stage III carcinomas (P = 0.78, ANOVA). The intraobserver agreement was poor for observer A (r = 0.28) and practically nonexistent for observer B (r = -0.004, Pearson correlation). The intraclass coefficient for interobserver agreement was practically nonexistent. No significant association between nuclear shape factor and ten-year survival was found.

CONCLUSIONS

Our prospective results, as opposed to our previous retrospective results, suggest that the reliability for nuclear shape factor morphometric analysis is very poor. We failed to confirm a prognostic value for nuclear shape factor in colorectal carcinoma.

Benign Hürthle cell adenoma with papillary architecture: a benign lesion mimicking oncocytic papillary carcinoma

We studied the significance of encapsulated Hürthle cell thyroid nodules with papillary structures lacking the nuclear features of papillary thyroid carcinoma (PTC); 19 cases fulfilling these criteria were encountered The patients' ages ranged from 22 to 40 years (32+/-6), and the F:M ratio was 3:1 The tumors measured from 0.5-5 cm (2+/-1.1). The diameter of the tumor cell nuclei ranged from 5.6 to 7.2 microns. Many nodules had nuclei displaying a fine chromatin pattern somewhat resembling those of PTC, but these were present in <20% of the tumor cells. Immunohistochemically, there was reactivity for MIB-1 in the papillary structures, negativity to focally weak reactivity for HBME and galectin-3, and negativity to moderate diffuse reactivity for CK19. Clinical follow-up from 1 to 19 years revealed no evidence of metastases in any of the cases. It is unlikely that the papillary structures in the study cases represent degenerative changes in view of the proliferative activity we have demonstrated in them. In view of (1) the encapsulation and the uniformity of the constituent cells, (2) the negative or weak immunoreactivity for galectin-3 and HBME and negative to moderate immunoreactivity for CK19, and (3) the absence or paucity of nuclear criteria for the diagnosis of PTC and the absence of lymph node metastasis in all study cases, we believe that these lesions represent the papillary variant of oncocytic follicular adenoma (Hürthle cell adenoma). Recognition of this entity is important to avoid an overdiagnosis of oncocytic PTC.

Computerized Morphometric Study of Thyroid Follicular Carcinoma in Correlation with Known Prognostic Factors

This study investigates the correlation between computer-assisted nuclear morphometry and known prognostic factors in thyroid follicular carcinoma. Thirty-six patients with thyroid follicular carcinoma who underwent surgery between 1991 and 2001 were grouped according to sex, age, size of the primary lesion, the presence of vascular invasion, and metastases. Four nuclear parameters were measured and analyzed: mean nuclear area, mean nuclear perimeter, largest to smallest diameter ratio of the nuclei, and coefficient of variation of the nuclear area. Our results indicated that none of the chosen nuclear variables were significantly correlated with the prognostic factors studied. In conclusion, nuclear morphometry does not seem to correlate with known prognostic factors and cannot serve as an additional predicting factor for biologic behavior.

Follicular adenoma with papillary architecture: a lesion mimicking papillary thyroid carcinoma

AIMS

The purpose of this study was to investigate the significance of 'benign' encapsulated follicular thyroid nodules with papillary structures.

METHODS AND RESULTS

Twenty-one cases of encapsulated neoplastic thyroid nodules with papillary structures and nuclear features not diagnostic of papillary thyroid carcinoma (PTC) were obtained. All cases were reviewed with particular attention to nuclear features (fine chromatin pattern, optical clearing, grooves and inclusions). Representative sections were submitted for measurement of the maximum diameter of 200 round or nearly round nuclei and for immunostaining for MIB1, CK19, HBME and Ret oncogene protein. Nine cases displayed scattered optically clear nuclei or nuclear grooves in less than 30% of total neoplastic cells. They were grouped in the category of thyroid nodules with limited nuclear features of papillary thyroid carcinoma (PTC), but not diagnostic of PTC. The other 12 cases had fine or coarse chromatin, but lacked other features of nuclei in PTC. The diameter of the nuclei ranged from 5.6 to 7.2 microm and were smaller than those of PTC (6.3-10.0 microm). Immunostaining revealed positive reactivity for MIB1 in the papillary structures. Immunostaining for CK19 and HBME varied from negative or focally weak to diffusely moderate reactivity. Ret oncogene protein immunostaining showed focal and weak reactivity in one case and was negative in other cases of the study. Clinical follow-up from 6 months to 15 years revealed no evidence of metastasis.

CONCLUSIONS

The papillary structures in the study cases are unlikely to represent degenerative changes due to their proliferative activity. In view of (i) the encapsulation and the uniformity of the constituent cells, (ii) the varying degrees of immunoreactivity for CK19 and HBME and negative immunoreactivity for Ret oncogene protein, and (iii) the absence or insufficiency of nuclear criteria for the diagnosis of PTC and the absence of lymph node metastasis in all study cases, we believe that these lesions represent the papillary variant of follicular adenoma. Recognition of this pathological entity is important to avoid an over-diagnosis of PTC.

A morphometric analysis of cytological features of tall cell variant and classical papillary carcinoma of the thyroid

In order to assess whether morphometric parameters could be of value in distinguishing between tall cell variant and classical pattern of thyroid papillary carcinoma, the fine needle aspiration cytology (FNAC) samples of 14 cases were analysed using Arcimage 5 software on an Acorn computer. Histological examination of the specimens allowe classification of nine of them as classical pattern and the remaining five as tall cell variants. The nuclear diameter (NDD) and standard deviation distribution (NDSDD), th nuclear area (NAD) and standard deviation distribution (NASDD), and the nuclear/cytoplasmic ratio (NCR) were assessed on May-Grunwald-Giemsa stained smears. Statistical analysis was performed by use of one-way analysis of variance (ANOVA) of the two groups as identified by histology. Whilst NDD (P = 0.007), NAD (P = 0.015) and NADSD (P = 0.026) all appeared statistically significant, NDSD (P = 0.06) and NCR (P = 0.71) were not. The cytological diagnosis of papillary carcinoma is established and reproducible, but morphometric data on the thyroid have so far focused on the differential diagnosis between benign and malignant nodules. The choice of simple morphometric parameters appears to be helpful in the preoperative distinction between the classical pattern and tall cell variant of papillary carcinoma.

Neoplastic non-papillary thyroid carcinoma lesions with a fine chromatin pattern

In papillary thyroid carcinoma (PTC) in cytological and surgical specimens, fine chromatin, nuclear grooves and nuclear pseudoinclusions are the hallmarks of diagnosis. We investigated the significance of these nuclear changes in neoplastic non-PTC lesions. Fine needle aspiration biopsies (FNAB) of thyroid lesions were reviewed with histologic correlation. Twenty-five low-grade PTC and 35 neoplastic non-PTC lesions with a fine chromatin pattern in cytology specimens were identified. These lesions were studied along with five multinodular goiters and five follicular adenomas with a coarse chromatin pattern. The neoplastic non-PTC lesions were selected from cases with a histopathologic diagnosis of follicular neoplasm (accompanied by cytopathologic examination) but lacking a coarse chromatin pattern. The nuclear changes were separated into three grades of nuclear atypia with a fine chromatin pattern, depending on the degree of nuclear enlargement and nuclear membrane thickening, or the presence of nuclear grooves or pseudoinclusions. Thyroid lesions with a higher grade of nuclear atypia with a fine chromatin pattern were associated with larger nuclei and more readily visible nucleoli. These lesions correlated histologically with PTC and follicular adenomas with a fine chromatin pattern. The latter could be divided into three grades: grade 1 lesions having a fine chromatin pattern similar to that of nuclei with open chromatin seen in areas of nodular goiter; grade 3 lesions having nuclear features closest to those of PTC; and grade 2 lesions showing intermediate changes. In conclusion, there is a spectrum of nuclear changes in neoplastic non-PTC lesions with a fine chromatin pattern. These lesions are often diagnosed as follicular adenomas in surgical pathology and pose cytopathologic diagnostic problems between nodular goiter, follicular adenoma and PTC. The significance of follicular adenomas with a fine chromatin pattern will be discussed.

Cytopathology of high-grade papillary thyroid carcinomas: tall-cell variant, diffuse sclerosing variant, and poorly differentiated papillary carcinoma

Cytologic reports of the aggressive tall-cell and diffuse sclerosing variants of papillary carcinoma have emphasized features such as tall and large cells, increased nuclear size, nuclear pleomorphism, intranuclear pseudoinclusions, three-dimensional tissue fragments, squamous-like cells, and dense inflammatory background as characteristic features. However, the specificity of these features in identifying the particular variants and distinguishing them from other poorly differentiated papillary carcinomas and typical low-grade forms of papillary carcinoma has not been established. The objective of this study was to assess the predictive value of these reported cytologic features. Fourteen cases of high-grade papillary carcinoma consisting of the aggressive variants (tall-cell variant (tcv) and diffuse sclerosing variant (dsv)) and poorly differentiated papillary carcinomas (pdpc) were compared to 18 cases of low-grade papillary carcinoma. Seven cytologic features consisting of the presence of tall and large cells, architectural disorganization, nuclear enlargement, prominent intranuclear pseudoinclusions, nuclear pleomorphism, lymphocytic infiltrate, and squamoid appearance of the neoplastic cells were evaluated. Cytology samples from tcv, dsv, and pdpc consistently demonstrated 3 of the 7 cytologic features (architectural disorganization, nuclear enlargement, and pleomorphism). In contrast, only two of the samples from low-grade cases demonstrated these 3 features. The recognition of these 3 cytologic features had a positive predictive value of 88% and a negative predictive value of 100% for identifying tcv, dsv, and pdpc. The remaining cytologic features were not a consistent feature in the variants, and by cytology alone, distinction between the aggressive variants (dsv and tcv) and pdpc could not be made.

Selective expression of CD44 cell-adhesion molecule in thyroid papillary carcinoma fine-needle aspirates

Recent descriptions of numerous pitfalls in the cytologic diagnosis of thyroid papillary carcinoma on fine-needle aspiration biopsy specimens have prompted studies of new ancillary diagnostic methods. We evaluated the potential use of immunocytochemical staining of thyroid fine-needle aspiration biopsy specimens for CD44, a glycosylated cartilage link protein associated with extracellular matrix adhesion and lymphocyte homing. Fourteen of 16 (88%) classic, surgically confirmed, thyroid aspiration biopsies stained intensely positive for this marker, whereas 0 of 30 (0%) similarly-processed benign aspirates from colloid nodules showed immunoreactivity for CD44 antigen. From this study, we conclude that most papillary carcinomas of the thyroid express the celladhesion molecule CD44, which may be of clinical value in confirming the diagnosis on borderline fine-needle aspiration specimens. Further study of CD44 expression may prove of significant interest in explaining the unusual mode of spread and clinical course of this disease.

Diagnostic value of AgNOR method in thyroid cytopathology: correlation with morphometric measurements

A silver staining technique was applied to 51 thyroid smears. The numbers of silver-stained nucleolar organizer regions (AgNORs) were counted, and the mean AgNOR and nuclear area per cell were determined with an image analyzer. The mean AgNOR count per cell was significantly higher in malignant than in benign lesions, but there was a considerable overlap. The mean AgNOR area and the mean SD of the AgNOR area per cell were significantly higher in carcinomas than in benign lesions (P = 10-9 and P = 5 x 10-10, respectively) and there were only two and one benign cases, respectively, of overlap. A strong correlation was observed between the mean AgNOR area and the mean nuclear area (r = 0.88), the former being a better discriminator between benign and malignant lesions. The AgNOR technique may contribute to routine thyroid cytopathology.

Macrofollicular Variant of Papillary Thyroid Carcinoma: A Case and Control Analysis

The planimetric, flow cytometric, and immunohistochemical characteristics of the macrofollicular variant of papillary thyroid carcinoma (MFVPTC) have not been reported before. The clinical, morphological, immunohistochemical, planimetric, and flow cytometric characteristics of six cases of the MFVPTC and six of the follicular variant of papillary thyroid carcinoma (FVPTC) were analyzed. Patients had undergone surgical treatment. The mean age was 38 (range 29-64 yr), and five were women. Tumors had a mean size of 3.2 cm (range 0.3-4.5 cm). Half were originally diagnosed as goiter. Macrofollicles had a mean diameter of 345.5 um, perimeter of 1237 um, and area of 13,779 um(2), with nuclear changes of PTC. Mean follow-up was 107 mo (range 12-277), and neither lymph node metastases nor recurrence were seen. Differences in diameter, perimeter, and area between the macrofollicular and follicular variants were found. Follicular neoplastic cells were thyroglobulin and 5-100 protein positive in macrofollicles and normofollicles. All were negative to cytokeratin and to high-mol-wt keratin. All tumors were diploid. There were no significant differences in follow-up, DNA content, nor immunohistochemical reactivity. Differences in diameter (p < 0.00006), perimeter (p < 0.0001), and area (p < 0.001) were observed. It is important to recognize this variant because it could be misdiagnosed as benign thyroidal lesions.

Morphonuclear characterization of drug resistance by means of digital cell-image analysis: an in vitro assessment

The prediction of tumor resistance to antineoplastic drugs remains an important challenge in cancer chemotherapy. Several methods have been proposed in this connection, but they present a number of problems such as clinical relevance and applicability. In the present work we put forward an original methodology to assess the drug sensitivity of cancer cells. For this purpose we submitted chemosensitive and chemoresistant cell lines to different anticancer drugs and monitored the cell growth and the drug-induced morphonuclear effects by means of digital cell-image analysis of Feulgen-stained nuclei. The results showed that drug-induced effects at the morphonuclear level correlated statistically with the effects produced at the cell proliferation level. For example, the mean nuclear size value increased as a function of the drugs' efficiency recorded at the cell proliferation level. In the same way, the frequency of large dense chromatin clumps also increased in accordance with the drugs' efficiency. The present work thus demonstrates that digital cell-image analysis can be applied to monitor the efficiency of chemotherapeutic treatment carried out on cell lines in vitro. The present methodology could possibly be used on solid tumors, from which biological material can be obtained serially by means of fine-needle aspiration. As evidence of this, the present methodology can also be applied to hematological cancers.

Nuclear quantitative grading by discriminant analysis of renal cell carcinoma samples. A patient survival evaluation

Specimens from 60 cases of renal cell carcinoma (RCC) were graded employing quantitative nuclear data combined with multivariate discriminant analysis. Evaluation of patient survival was analysed with respect to quantitative microscopic and qualitative features. Both morphometric and stereological estimators were used to establish the nuclear size and form pattern of the RCC specimens. Tumoural dedifferentiation paralleled progressive increases in nuclear elongation and in two- and, especially, three-dimensional--mean nuclear volume (MNV)--size parameters. Using stepwise discriminant analysis, 85.0 per cent of the specimens were correctly classified when differentiating grade 2 and 3 tumours. It is concluded that simple and realistic estimates of MNV are the best discriminator for objective grading in patients with RCC. Univariate survival analysis demonstrated the important significance of several features such as MNV, clinical stage, and nuclear discriminant and histopathological tumour grades. Nuclear form factor PE, area, and perimeter were also significant. A prognosis study based on the Cox model using a stepwise selection of parameters showed that only MNV has an independent prognostic role when examining all investigated quantitative parameters. The clinical stage was the best prognostic feature when all quantitative and qualitative characteristics were included in the analysis.

Value of volume weighted mean nuclear volume in grading and prognosis of renal cell carcinoma

AIMS

To perform stereological quantitation of volume weighted mean nuclear volume in renal cell carcinomas; and to correlate the data obtained with recognised clinical and pathological variables and determine their prognostic value.

METHODS

The point-sampled intercepts method was used to estimate mean nuclear volume in 63 cases of clear cell renal carcinoma diagnosed between 1980 and 1988. New paraffin wax embedded histological sections were analysed after systematic sampling and the test systems superimposed on a projected microscopic image to measure nuclear intercept lengths. After mathematical estimation of mean nuclear volume, statistical analyses of the data in relation to clinical and pathological variables as well as the prognostic impact were investigated.

RESULTS

The mean nuclear volume was significantly associated with tumour dedifferentiation. However, mean nuclear volume showed no statistical differences with sex, age, and clinical stage. The prognostic value of mean nuclear volume, nuclear grading, and clinical stage in renal cell carcinomas was high: mean nuclear volume greater than 140 micron3 was associated with short term survival.

CONCLUSIONS

Measurement of mean nuclear volume was useful as a guide to objective grading of renal cell carcinomas, though there was an overlap between tumour grades. Based on the limited number of cases analysed, the mean nuclear volume is proposed as an additional prognostic indicator.

Prognostic importance of histologic grading in papillary thyroid carcinoma

BACKGROUND

The influence of various clinicopathologic features on survival of patients with papillary thyroid carcinoma has been examined. In particular, histologic grade, which was obtained by a combined assessment of nuclear atypia, tumor necrosis, and vascular invasion (VAN score) was studied. According to this, histologic grade is independent of growth pattern and differentiation of the tumor cells.

METHODS

One hundred seventy-three consecutive patients were studied retrospectively, and most were treated with total/near-total thyroidectomy. Univariate (life-table) and multivariate (Cox regression) analyses of thyroid cancer deaths were performed.

RESULTS

Histologic grade showed a highly significant prognostic impact. It was possible to discriminate between low-grade (Grade 1) and high-grade (Grade 2) tumors, occurring in 79% and 21% of the patients, respectively. The risk of thyroid cancer deaths was found to be considerably higher in the latter group of patients. When histologic grade was combined with sex and age, a highly significant prognostic score (the SAG score) was obtained.

CONCLUSION

Histologic grade based on nuclear atypia, tumor necrosis, and vascular invasion is a strong and independent prognostic factor. When combined with patient sex and age, the final SAG score and the pTNM-age classification were both significant and should be considered in prognostic stratification of these patients.

Correlation of nuclear morphometry and DNA ploidy in rectal cancer

Several investigators have used morphometric measurements to determine differences in the nuclear size and shape of normal and neoplastic colorectal tissue. Changes in nuclear morphometric parameters have also been shown to correlate with prognosis in a variety of noncolorectal cancers. The association of nuclear morphometry with prognostic indicators in rectal cancer has not been well studied. Measurements of the nuclear area, perimeter, longest cord, and circularity factor from 39 primary rectal adenocarcinomas were compared with DNA content, degree of tumor differentiation, Dukes' class, and patient survival. Nuclear circularity was found to correlate with DNA ploidy. Nondiploid tumors with a DNA index greater than 1.3 had significantly more circular nuclei than tumors with diploid or near-diploid DNA content. There was no correlation between nuclear morphometry and Dukes' class or patient survival. Significant increases in DNA content of rectal cancers appear to be reflected by measurable changes in nuclear shape. Nuclear morphometric measurements may provide useful information in the study of the progression of neoplastic changes in colorectal cancer.

How malignant is malignant? A brief review of the microscopic assessment of human neoplasms, and the prediction of whether they will metastasize and kill

This review examines ways in which histopathologists can attempt to predict the degree of malignancy from the microscopic examination of surgically removed samples of human neoplasms. These include mitotic counts, measurement of DNA content, analysis of DNA turnover, measurement of proliferation antigens, measurement of nucleolar organizing areas, counting nucleoli, morphometry of nuclei, identification of genetic change, measurement of lysis of basement membrane, and measurement of invasion in vitro. The latter two are not currently of practical value. Of the rest none is uniformly capable of predicting the degree of malignancy of a human neoplasm. After further refinement and control measurement of several such parameters may however contribute more to the prediction of malignancy than present subjective assessments.