Prognostic significance of nuclear morphometry in superficial bladder cancer

OBJECTIVE: To evaluate the significance of nuclear morphometry in predicting the clinical course in superficial (pTa and pT1) bladder cancer. STUDY DESIGN: The study included 73 patients with superficial transitional cell carcinoma of the bladder who were followed for a median of 21 months (range, 1-90). Nuclear morphometry was performed by a computer-assisted image analyzer system on hematoxylineosin-stained histologic sections and characterized by five nuclear variables: area, perimeter, major and minor diameter, and form factor. Patient charts and microscopic slides were reviewed to record tumor stage, grade and size. Tumor proliferative activity was assessed by immunohistochemical staining with Ki-67 antibody. RESULTS: None of the morphometric variables showed a significant relation to tumor progression and recurrence. Higher values of mean nuclear area, perimeter, and major and minor diameter were significantly related to higher grade and proliferative activity. Mean nuclear area and minor diameter were associated with advanced stage. Of established prognostic factors, only histologic grade was significant in predicting progression. CONCLUSION: The results suggest that nuclear morphometry may be valuable in determining proliferative activity and may be well correlated with histologic grade in superficial bladder cancer. However, like many other potential prognostic factors, it seems to be unreliable in predicting clinical behavior.     

Quantitative microscopy of human DNA topoisomerase II-alpha expression in transitional cell carcinoma of the bladder

OBJECTIVE: To compare the nuclear size of various grades of transitional cell carcinoma (TCC) stained immunohistochemically with the nuclear enzyme topoisomerase II-alpha (topo II-alpha) in bladder urothelial neoplasms. STUDY DESIGN: Histologic sections from 53 consecutive papillary bladder neoplasms were stained immunohistochemically for topo II-alpha expression. There were 18 (33.9%) urothelial neoplasms of low malignant potential (UNLMP), 18 (33.9%) low grade urothelial carcinoma (LGUCa), and 17 (32%) with high grade urothelial carcinoma (HGUCa). The histologic slides were photographed at 400 x magnification and then projected on a screen, and the area with stained nuclei was measured. RESULTS: The cells and nuclei in HGUCa were significantly larger than in LGUCa (P < .05) and UNLMP (P < .01). CONCLUSION: Calculation of the area fraction of nuclei in TCC of the bladder stained with topo II-alpha is an additional method of establishing the grade of these tumors.     

Mean nuclear area of fine needle aspirates of primary preoperative palpable breast carcinoma using image cytometry

OBJECTIVE: Early, operable breast cancers in appropriate patients are increasingly being treated preoperatively using neoadjuvant chemotherapy. A good response rate is seen with high grade tumors. Nuclear size, which may reflect the grade of the tumor, is also of possible prognostic value in breast cancer. STUDY DESIGN: We measured the mean nuclear area (MNA) of 114 consecutive preoperative fine needle aspirates of palpable, operable breast cancers. We used computerized image cytometry to measure nuclear area to determine tumor biology and possible grade prior to treatment. RESULTS: Histologic grade distribution was as follows: low grade, 15%; moderate grade, 40%; and high grade, 45%. Mann-Whitney test for trend on tumor size and histologic grade between MNA showed a significant relationship between MNA and tumor size (P=.016) but no significance between MNA and histologic grade (P =.22). The chi2 and Fisher Exact Test between MNA and node-positive or -negative patients showed no significance. CONCLUSION: When correlating MNA with tumor size and histologic grade, high MNA is present at a higher frequency as tumor size and histologic grade increase.     

Expression of Claudins and Their Prognostic Significance in Noninvasive Urothelial Neoplasms of the Human Urinary Bladder

The members of the claudin family are major integral transmembrane protein constituents of tight junctions. Normal and neoplastic tissues can be characterized by unique qualitative and quantitative distribution of claudin subtypes, which may be related to clinicopathological features. Differential diagnosis and prognosis of nonmuscle invasive tumor entities of urinary bladder epithelium are often challenging. The aim was to investigate the expression profile of claudins in inverted urothelial papillomas (IUPs), urothelial papillomas (UPs), papillary urothelial neoplasms of low malignant potential (PUNLMPs), and intraepithelial (Ta), low-grade urothelial cell carcinomas (LG-UCCs) in order to reveal potential prognostic and differential diagnostic values of certain claudins. Claudin-1, -2, -4, and -7 protein expressions detected by immunohistochemistry and clinical data were analyzed in 15 IUPs, 20 UPs, 20 PUNLMPs, and 20 LG-UCCs. UPs, PUNLMPs, and LG-UCCs showed significantly decreased claudin-1 expression in comparison to IUPs. LG-UCCs expressing claudin-4 over the median were associated with significantly shorter recurrence-free survival. PUNLMPs expressing claudin-1 over the median revealed significantly longer recurrence-free survival. High claudin-1 protein expression might help to differentiate IUP from UPs, PUNLMPs, and LG-UCCs. High claudin-4 expression may determine an unfavorable clinical course of LG-UCCs, while high claudin-1 expression in PUNLMP was associated with markedly better clinical outcome.     

Clinical and cytologic features of papillary neoplasms of the breast

OBJECTIVE: To compare the cytologic features benign and malignant papillary breast lesions. STUDY DESIGN: We reviewed the clinical and cytologic features in 29 cases of intraductal papilloma and 26 cases of atypical papilloma or papillary carcinoma that had been diagnosed by histologic examination. The diameter of the mass was examined as a clinical feature. The cytologic features evaluated were as follows: bloody background, row of tall columnar cells, naked bipolar nuclei, hemosiderin-laden macrophages, myoepithelial cells, single scattered atypical cells, cellularity, nuclear atypia, nuclear grade, apocrine metaplasia, eosinophilic cytoplasmic granules, papillary clusters, small papillae, cell balls and large sheets. RESULTS: Of the features evaluated, the diameter of the mass, naked bipolar nuclei and cell balls differed significantly between benign and atypical or malignant papillary neoplasms. The average diameter of a benign papillary neoplasm was 1.8 cm, and that of an atypical or malignant papillary neoplasm was 2.2 cm (p = 0.042). Naked bipolar nuclei were found in 27 cases of benign papillary neoplasm (93.1%) versus 19 cases of atypical or malignant papillary neoplasm (73.1%) (p = 0.050). Cell balls were found in 14 (48.3%) and 21 (80.8%) cases, respectively (p = 0.012). All 6 cases in which cell balls were present and naked bipolar nuclei were absent proved to be atypical or malignant papillary neoplasms. Of 17 cases in which cell balls were absent and naked bipolar nuclei present, 13 (76.5%) were benign papillary neoplasms. CONCLUSION: Most cytologic features overlapped in benign and atypical or malignant papillary neoplasms. Although they were not pathognomonic, naked bipolar nuclei and cell balls were cytologic features that differed significantly between benign and atypical or malignant papillary neoplasms. When papillary neoplasms of the breast are suspected in a cytologic smear, the combination of clinical examination, mammography and cytologic features should be considered to make the correct diagnosis.     

Value of computer‐assisted quantitative nuclear morphometry for differentiation of reactive renal tubular cells from low‐grade urothelial carcinoma

H. Ohsaki, E. Hirakawa, K. Kagawa, M. Nakamura, H. Kiyomoto and R. Haba Value of computer‐assisted quantitative nuclear morphometry for differentiation of reactive renal tubular cells from low‐grade urothelial carcinoma Objective: To assess whether computer‐assisted quantitative morphological parameters can be an effective tool for objectively distinguishing reactive renal tubular cells from low‐grade urothelial carcinoma cells (LG‐UCs) in voided urine. Methods: Nuclear morphometry was performed by a computer‐assisted image analyser system on Papanicolaou‐stained cytological specimens. The circumference of reactive renal tubular cells (n = 40) or LG‐UC (n = 20) nuclei were manually traced, and the following nuclear morphometric parameters were analysed: (i) area, (ii) perimeter, (iii) roundness factor, (iv) maximum length, and (v) linear factor. For each nuclear measurement, we calculated the maximum, minimum, mean and standard deviation. Results: The mean nuclear area and nuclear perimeter were higher in reactive renal tubular cells compared to the LG‐UCs. The mean of roundness and linear factors (reflecting a tendency for the nuclear outline to be regular and oval, respectively) were higher in LG‐UCs compared with reactive renal tubular cells. Among nuclear areas, the nuclear perimeter, roundness factors and maximum length did not show any significant differences between reactive renal tubular cells and LG‐UCs. On the other hand, the linear factor showed a mean higher value among LG‐UCs than reactive renal tubular cells (P = 0.023). Conclusions: Of five quantitative nuclear morphological parameters, only linear factor was statistically significant in differentiating reactive renal tubular cells in renal disease from LG‐UCs.     

Mean nuclear area of squamous cell carcinomas of the head and neck using image cytometry.

OBJECTIVE: To determine if mean nuclear area (MNA) in squamous cell carcinomas of the head and neck (SCCHN) correlate with the TNM system and histologic grade. STUDY DESIGN: We measured MNA by image cytometry on 74 primary SCCHN. Fify-five had primary surgery, 16 had radiotherapy, and 3 and both as their primary treatment. RESULTS: The mean MNA was 47.85 microm2 (range, 20.5-84.8). Tumor size, nodal status and histologic grade were, respectively: T1 = 13, T2 = 29, T3 = 18, T4 = 14; N0 = 53, N1 = 15, N2 = 5, N3 = 1; 17 = well, 38 = moderate, 19 = poorly differentiated. Spearman rank and Kruskal-Wallis tests for MNA/histologic grade, MNA/tumor size, MNA/nodal status and MNA/site were calculated; only MNA/node was statistically significant (P<.05). CONCLUSION: MNA increases in primary SCCHN as nodal involvement increases. This may reflect that high MNA may be a biologic marker of primary SCCHN with a poorer prognosis.     

Nuclear morphometry in canine acanthomatous ameloblastomas and squamous cell carcinomas

The aim of this study was to evaluate whether morphometrical analysis can be of diagnostic value for canine acanthomatous ameloblastoma. We calculated, by means of an automated image analyser, some morphometric nuclear parameters, in particular: mean nuclear area (MNA), mean nuclear perimeter (MNP), maximum and minimum diameters (MDx and MDm) coefficient of variation of the nuclear area (NACV), largest to smallest dimension ratio (LS ratio), and form factor (FF), in 8 canine acanthomatous ameloblastomas, and we compared these morphometric data to those of 13 squamous cell carcinomas of canine gingiva. The results indicated a progressive increase of the MNA, NACV, MNP and MDm proceeding from acanthomatous ameloblastomas (MNA: 42.11+/-8.74; NACV: 28,36+/-7,23; MNP: 24.18+/- 2.68; MDm: 5.69+/-0.49) to squamous cell carcinomas (MNA:49,69+/-9,10; NACV: 30,89+/-7,75; MNP: 25.63+/-2.54; MDm: 6.64+/-0.73). On the contrary, the LS ratio and the FF resulted greater in acanthomatous ameloblastomas (LS ratio: 1,63+/-0,12; FF: 1,13+/-0,002) than in SCCs (LS ratio: 1,40+/-0,12; FF:0.91+/-0.38). Moreover, the MNA, MNP,MDx and MDm resulted similar (MNA: p=0.89; MNP: p=0,65; MDm: p=0,16; MDx: p=0,13) in a subset of four acanthomatous ameloblastomas with cellular atypia (MNA:49,01+/-6,88; MNP: 26,28+/-1,99; MDm: 6.08+/-0.41; MDx: 10.18+/-0.88) and in squamous cell carcinomas (MNA:49.69+/-9,10; MNP: 25.63+/-2.54; MDm: 6.64+/-0.73; MDx: 9.26+/-1.05). While the NACV values resulted higher in typical acanthomatous ameloblastoma (29,99+/-6,06) than in atypical acanthomatous ameloblastoma (26,74+/-8,84) and similar to those of the SCCs (30,89+/-7,75). These results seem to confirm that acanthomatous ameloblastoma is a malignant or potentially malignant lesion and emphasizes that nuclear morphometry analysis can be an useful diagnostic and prognostic method in canine oral pathology.     

Prognostic significance of DNA image cytophotometry for osteosarcoma

OBJECTIVE: To investigate the prognostic significance of DNA image cytophotometric data. STUDY DESIGN: Twenty-six osteosarcomas in patients without lung metastases were investigated for several cytophotometric data. In 24 cases, these data were correlated with the clinical course of the patients to assess the prognostic value of nuclear DNA content in osteosarcomas. RESULTS: Of all osteosarcomas, 96% showed aneuploid DNA content. Patients with tumors having a 2c deviation index (2cDI) of 12.00, DNA malignancy grade (DNA-MG) of 2.0, a mean DNA content (MDC) of 4.95 c, DNA index (DI) of 1.75 or mean nuclear area (MNA) of 130 microns 2 had a significantly lower overall survival rate as compared to those with lower values (P < .05). CONCLUSION: Image cytophotometric features, such as 2cDI, DNA-MG, MDC, DI and MNA, are of prognostic value in patients with osteosarcoma and free of lung metastases.     

Endocervical atypical glandular cells of undetermined significance. II. Morphometric and cytologic analysis of nuclear features useful in characterizing differently correlated subgroups

OBJECTIVE: To evaluate whether some nuclear features analyzed by morphometry and cytology may be useful in characterizing differently correlated endocervical atypical glandular cells of undetermined significance (AGUS) subgroups. STUDY DESIGN: Fifty-four endocervical AGUS smears were subclassified into four subgroups on the basis of their different correlation: not otherwise specified subgroup (NOSs), tamoxifen (Ts), human papillomavirus infection (HPVs) and laser therapy (LTs). Area and shape of the atypical nuclei detected were morphometrically measured. The smears were then cytologically reviewed, and the shape and grade of expression of hyperchomasia in AGUS nuclei were analyzed. RESULTS: AGUS cases due to T therapy showed the largest nuclear area (148.845 micron 2; P < .0000) and the greatest anisonucleosis objectively measured by morphometry. HPVs had the shape that most differed from perfectly circular (15.341 versus 14.1) and showed the highest grade of expression of nuclear density. LTs and NOSs were less well characterized than the other subgroups. CONCLUSION: Analysis of nuclear features by morphometry and cytology was useful in characterizing the AGUS subgroups Ts and HPVs.     

Cell kinetics analysis in stage I endometrial carcinoma as determined by image cytometry and immunohistochemistry. Correlation with clinicopathologic characteristics

OBJECTIVE: To test the significance of various proliferative indices in endometrial carcinoma (EC) since previous investigations failed to yield consistent results that would establish them as factors of clinical importance. STUDY DESIGN: Seventy patients with EC were evaluated for various proliferative indices (mitotic index, Ki-67 index, argyrophilic nucleolar organizer (AgNOR) number and area per nucleus, and p53 protein expression) in relation to image cytometry (nuclear area, diameter and roundness) and standard clinicopathologic features (age, histologic type and grade, and depth of invasion). We also tested the proliferation index (PI), which combines the Ki-67 index and AgNOR area in Ki-67-positive nuclei. Slides from each case were double stained for Ki-67 antigen and AgNOR proteins for this purpose. RESULTS: Mitotic counts were significantly higher in papillary-serous (vs. endometrioid) tumors (P = .0001), high grade (vs. low grade) tumors (P = .0001), deeply invasive (P = .017) and p53-positive tumors (P = .017). AgNOR counts correlated only with age (higher in older women, P = .002), while the PI correlated with mitotic counts (P = 0.28) and marginally with depth of invasion (P = .06). Morphometric variables were associated just with histologic type and grade. p53 Protein was expressed exclusively in invasive tumors and was related strongly to histologic type (P = .0029) and grade (P = .0001). CONCLUSION: Our data reestablish the value of classic histopathologic features (mitotic index, histologic type and grade) as the most important tools for EC evaluation. In addition, we suggest that p53 immunostaining may be used for predicting aggressive behavior in EC.     

Morphometry in surgical pathology

The potential role of morphometry in surgical pathology is discussed. Specific areas in which morphometry could be helpful are in (1) identifying malignant cells in lesions that are largely composed of benign-appearing cells (e.g., follicular thyroid neoplasms), (2) defining reference points in apparent continua (e.g., in the progression from normal colon to adenoma to adenocarcinoma), (3) distinguishing between benign and malignant lesions with similar appearances (e.g., fibromatosis and fibrosarcoma of the soft tissue) and (4) distinguishing between similar-appearing types of malignant neoplasms (e.g., between small-cell carcinoma of the lung and small-cell lymphoma). Morphometric techniques are already being used in DNA ploidy determinations, which frequently bear prognostic information. The measurement of other nuclear and cellular parameters has been used for both diagnostic and prognostic ends; one example is the relation of nuclear roundness to metastatic potential in prostatic carcinomas. Morphometry is now being increasingly applied to histologic sections, as in the prognostic study of lesion thickness in malignant melanoma and the diagnostic study of glandular architecture in colonic adenoma. The use of morphometry can enhance the observation and interpretation of morphologic features, which, combined with the clinical data and the experience of the pathologist, can lead to greater accuracy and precision in surgical pathology diagnoses.     

Shape analysis of tumor cell nuclei in ependymomas by means of Fourier analysis

OBJECTIVE: To study the prognostic significance of nuclear shape analysis in ependymomas. STUDY DESIGN: Tumor cell nuclei in surgical specimens of primary resected ependymomas from 30 patients were evaluated by means of Fourier analysis of nuclear contours, conventional morphometric features (nuclear area, shape factor) and the Ki-67 proliferation index. Fourier analysis can be used for decomposing an irregular nuclear contour by calculating "Fourier amplitudes." Tumors with different tumor grades according to the World Health Organization were compared, as were patients with and without recurrence of ependymomas. Planimetric data were further correlated with the Ki-67 index. RESULTS: t Test and multivariate analysis showed distinct differences between ependymomas with tumor grade 3 and the other tumor grades. Cross-validated, stepwise discriminant analysis with the event of recurrence as grouping variable revealed correct reclassification in 16/18 cases without recurrence and of 10/12 cases with recurrence. When considering just intracranial ependymomas with total surgical removal, Fourier amplitudes provided 100% correct reclassification concerning recurrence. Proliferation index, in contrast, showed considerable overlap between all tumor grades and between cases with and without recurrence. CONCLUSION: Quantification of the shape of tumor cell nuclei in ependymomas by means of Fourier analysis has prognostic significance and seems to be superior to the Ki-67 index.     

Morphometric image analysis of follicular lesions of the thyroid

OBJECTIVE: To determine the role of image morphometry in distinguishing various follicular lesions of the thyroid in cytologic smears. STUDY DESIGN: Archival fine needle aspiration smears of 10 cases each of follicular hyperplasia, follicular adenoma, follicular carcinoma and follicular variant of papillary carcinoma were used for the study. All cases were histopathologically proven. At least 100 random nuclei from each case were subjected to analysis with an image cytometer. Area, convex area, length, width, perimeter, convex perimeter and roundness of nuclei were measured using a 40 x objective (1 pixel = 0.446 micron). RESULTS: ANOVA showed that all the nuclear variables studied were significantly different (P < .05) in follicular hyperplasia as compared to follicular carcinoma and papillary carcinoma. All nuclear variables except roundness were also significantly different (P < .05) between follicular hyperplasia and follicular adenoma. However, between follicular adenoma, follicular carcinoma and papillary carcinoma there was considerable overlap of nuclear morphometric parameters. CONCLUSION: Image morphometry may help to distinguish nonneoplastic follicular lesions (hyperplasia) from neoplastic lesions (adenomas and carcinomas). However, to distinguish benign from malignant follicular lesions, image morphometry might not improve the accuracy of standard cytologic examination.     

Correlation between preoperative magnetic resonance spectroscopic data on high grade gliomas and morphology of Ki-67-positive tumor cell nuclei

OBJECTIVE: To investigate possible statistical correlations between metabolic data from preoperative proton magnetic resonance spectroscopy (1HMRS) and morphology of proliferating tumor cell nuclei in anaplastic gliomas and glioblastomas. STUDY DESIGN: Ki-67-positive tumor cell nuclei in paraffin sections of surgical specimens from 36 patients (7 anaplastic gliomas, World Health Organization grade 3; 29 glioblastomas, World Health Organization grade 4) were investigated by means of a digital image analysis system. Stringent inclusion criteria were formulated for all cases with respect to histologic quality and spectroscopic examination. As morphometric variables, nuclear area, shape variables (roundness factor, size-invariate Fourier amplitudes) and density of Ki-67-positive tumor cell nuclei per reference area were determined. RESULTS: Correlation analysis according to Spearman revealed a significant positive correlation between the total creatine (TCR) peak and nuclear area (P = .005). This correlation was also found within the glioblastoma group (P = .019). There was also a significant negative correlation of nuclear area with the ratio between choline and TCR in all cases (P = .014) and within the glioblastoma group (P = .046). No significant correlation of spectroscopic data was found with nuclear shape or density of Ki-67-positive tumor cell nuclei. CONCLUSION: The results demonstrate a correlation between spectroscopic data and morphology of proliferating tumor cell nuclei (nuclear size) in high grade gliomas. This study is part of a detailed investigation of the interrelationship between preoperative 1HMRS and quantitative histomorphology of gliomas.     

Proliferating cell nuclear antigen in normal urothelium and urothelial lesions of the urinary bladder: a quantitative assessment using a true color image analysis system

To evaluate proliferating cell nuclear antigen (PCNA) staining for assessing proliferative activity in routine pathology specimens of urinary bladder, the bladder carcinoma cell line J82 and a total of 122 specimens of normal bladder and urothelial lesions were stained with the antibody clone PC10 against proliferating cell nuclear antigen. In in vitro plateau cultures the proportion of PCNA-positive cells exceeded that of Ki-67-positive cells, and only very few cells were negative. In formalin-fixed tissues, the PCNA staining pattern, which should be confined to replicon units in the nucleus, was optimized by 1 h postfixation in an organic solvent (methacarn). Sections showed positive nuclear staining confined to basal and some suprabasal cells in normal urothelium and grade 1 dysplasias, but more generalized nuclear staining in all other neoplastic lesions. In addition, stromal cells adjacent to invasive tumors showed nuclear positivity in some instances. Using quantitative true color image analysis of sections counterstained with hemalum, the degree of brown staining of the PCNA reaction product is contrasted with the blue staining of the nuclear area. With this method low contrast specific staining not appreciated optically can be reliably detected. Image analysis data confirmed observations made on noncounterstained sections and showed significant differences between grade 1 and 2 dysplasias as well as between grade 1 dysplasia and all grades of papillary tumor. Furthermore, a significant difference in PCNA staining indices was found between grade 1 and 3 bladder carcinomas. The results indicate that PCNA staining using the PC10 antibody is not confined to the proliferative fraction of neoplastic urothelium. In contrast with data from normal tissue and malignant hematological neoplasms, the amount of PCNA is regulated differently in urothelial neoplasms, emphasizing the biological differences between the following two sets: mild dysplasia and moderate dysplasia; mild dysplasia and papillary carcinomas. The use of image analysis to standardize the detection process after controlled staining conditions is advisable in order to provide reliable data. Supported by the DFG project: Knuechel/Urothelcarcinom 263     

Expression of CD44 and cyclin D1 in fine needle aspiration cytology of papillary thyroid carcinoma

OBJECTIVE: To compare the expression pattern of CD44 and cyclin D1 immunostaining in fine needle aspiration specimens of papillary carcinoma of the thyroid and nonpapillary lesions. STUDY DESIGN: The study was performed on 80 fine needle aspiration cytologic smears of thyroid lesion retrospectively using monoclonal antibodies and on histologic material from a proportion of cases. RESULTS: Most papillary carcinomas expressed intense cell membrane or diffuse cytoplasmic staining for CD44 (97.8%). Focal immunoreactivity was observed in follicular neoplasms (28.5%) and nodular goiter (4.7%). There was no difference in CD44 immunostaining between follicular carcinoma and adenoma. Cyclin D1 was expressed in the nuclei of most papillary carcinomas (79.2%). Focal nuclear immunoreactivity was noted in nodular goiters (23.5%) and follicular neoplasms (10%). In resected specimens, all papillary carcinomas (19 cases) showed intense membranous or granular CD44 immunoreactivity. Focal cyclin D1 expression was noted in 52.6%. There was no difference in CD44 and cyclin D1 expression between the group of papillary carcinomas with regional lymph node metastasis as compared to those without metastasis. Positive staining for both CD44 and cyclin D1 would strongly favor papillary carcinoma, although further studies on cytologic material are necessary to verify this diagnostic approach. CONCLUSION: Most papillary carcinomas express CD44 and cyclin D1, whereas it is less common in follicular neoplasms and nodular goiter. This may be helpful in diagnostically difficult cases.     

Nuclear planimetry in renal-cell tumors

A morphometric study using conventional planimetry was carried out in 73 renal-cell tumors (64 adenocarcinomas and 9 adenomas) in order to correlate the objective nuclear measurements with some histologic and clinical data believed to have prognostic value. The use of a discriminant function to correctly separate adenomas and low-grade adenocarcinomas was also investigated. There was a strong association between the nuclear grade and the following parameters: nuclear area, nuclear major diameter and nuclear elongation. There was also a relationship between an adverse outcome and the major nuclear diameter and nuclear elongation. In a univariate survival analysis, only the clinicopathologic stage, the nuclear grade and the histologic presence of a pseudosarcomatous cell population had predictive value. Multivariate survival analysis using Cox models showed that the clinicopathologic stage, major nuclear diameter, presence of anaplastic cells and nuclear area had predictive value. Although the minor nuclear diameter reached a significant level, a discriminant function that would correctly separate adenomas and low-grade renal-cell carcinomas could not be formulated.