Image analysis evaluation of ploidy, S-phase fraction and nuclear area in canine mammary tumours

A Comparative Review of Mixed Mammary Tumors in Mammals

Mixed tumors are characterized by the histological identification of two or more cell types. Commonly, a mixture of epithelial and myoepithelial cells is included in abundant stroma, which can consist of myxoid, chondroid or bony matrices. Spontaneously arising mixed tumors are rare lesions in the human breast but are common in human salivary glands and canine mammary glands. Subtle histopathological characteristics and overlapping attributes of malignant lesions with other benign lesions can lead to a diagnostic challenge. Mixed tumors can present as benign or malignant. While malignant mixed tumors are quite rare in the human breast they have a poor prognosis. Benign mixed mammary tumors occur more frequently in female dogs than in humans and are usually associated with a good prognosis. This review will provide a comprehensive overview of mixed mammary tumors, across various mammalian species.

Nuclear morphometry in histological specimens of canine prostate cancer: Correlation with histological subtypes, Gleason score, methods of collection and survival time

Ten normal prostates, 22 benign prostatic hyperplasia (BPH) and 29 prostate cancer (PC) were morphometrically analyzed with regard to mean nuclear area (MNA), mean nuclear perimeter (MNP), mean nuclear diameter (MND), coefficient of variation of the nuclear area (NACV), mean nuclear diameter maximum (MDx), mean nuclear diameter minimum (MDm), mean nuclear form ellipse (MNFe) and form factor (FF). The relationship between nuclear morphometric parameters and histological type, Gleason score, methods of sample collection, presence of metastases and survival time of canine PC were also investigated. Overall, nuclei from neoplastic cells were larger, with greater variation in nuclear size and shape compared to normal and hyperplastic cells. Significant differences were found between more (small acinar/ductal) and less (cribriform, solid) differentiated PCs with regard to FF (p<0.05). MNA, MNP, MND, MDx, and MDm were significantly correlated with the Gleason score of PC (p<0.05). MNA, MNP, MDx and MNFe may also have important prognostic implications in canine prostatic cancer since negatively correlated with the survival time. Biopsy specimens contained nuclei that were smaller and more irregular in comparison to those in prostatectomy and necropsy specimens and therefore factors associated with tissue sampling and processing may influence the overall morphometric evaluation. The results indicate that nuclear morphometric analysis in combination with Gleason score can help in canine prostate cancer grading, thus contributing to the establishment of a more precise prognosis and patient's management.

Mammary Invasive Micropapillary Carcinoma in Cats: Clinicopathologic Features and Nuclear DNA Content

Invasive micropapillary carcinoma (IMC) is a variant of infiltrating ductal carcinoma of the breast associated with poor outcome. In this study, we report 16 carcinomas of the feline mammary gland displaying histologic features that correspond to IMC of the breast in women. The clinicopathologic findings, overall survival time, disease-free survival time, and nuclear DNA content of these cats were compared with 65 more common invasive mammary carcinomas (other feline mammary carcinoma [FMC]) of nonspecified type. IMC was associated with larger tumor size, higher histologic grade ( P < .0001), deeper muscle invasion ( P = .004), and more frequent lymphovascular invasion and nodal metastases ( P = .009 and P = .001, respectively) than other FMCs. The aneuploid pattern was more frequent in IMC lesions. IMCs were also associated with lower survival rates. In summary, all cases of feline IMC were associated with clinicopathologic features of high biologic aggressiveness and should be classified as independent histologic types of FMC.

Comparison of nuclear morphometric parameters in cytologic smears and histologic sections of spontaneous canine tumors

BACKGROUND

Nuclear morphometry may provide useful diagnostic and prognostic information for neoplasms in animals. Most available data have been obtained from histologic sections. Nuclear morphometry of cytologic smears may provide important preoperative information.

OBJECTIVE

The goal of this study was to compare nuclear morphometric parameters in cytologic smears and histologic sections from spontaneous canine tumors.

METHODS

Mean nuclear area (MNA), mean nuclear perimeter (MNP), mean nuclear form factor (FF; nuclear perimeter(2)/4pi nuclear area) and their respective SDs were assessed by image analysis of both hematoxylin and eosin-stained histologic sections and May-Grünwald-Giemsa-stained cytologic smears from the same case in 20 spontaneous canine tumors of different histogenesis. The above parameters were selected as being the best morphometric tools for measuring variation in shape and size in cells after neoplastic transformation. Data were compared by ANOVA with P<.01 considered significant.

RESULTS

There was a significant difference between histologic and cytologic specimens for MNA, MNP, and their SDs. Only the differences between FF and the SD of FF were not statistically significant.

CONCLUSIONS

Only nuclear morphometric data related to nuclear shape and nuclear shape variability are comparable between histologic and cytologic specimens. Nuclear area and perimeter may be affected by the different fixation and smear preparation techniques used in histology and cytology.

Nuclear morphometry in squamous cell carcinomas of canine skin

To investigate the diagnostic and prognostic value of nuclear morphometry in squamous cell carcinomas (SCCs) of canine skin, histological samples from 15 dogs were retrospectively analysed by computerized nuclear morphometry. In each case, the nuclei of at least 100 neoplastic cells were measured, and the mean nuclear area (MNA), standard deviation of MNA (SDa), mean nuclear perimeter (MNP), standard deviation of MNP (SDp), nuclear form factor (FF), and standard deviation of FF (SDf) were calculated. The morphometric data were examined in relation to tumour histological grade. No statistical differences were found between the different grades of SCC in terms of the mean values of SDa, SDp, FF or SDf. The MNA values, however, differed significantly between grades: I and III; I and IV; II and III; II and IV. The MNP values differed significantly between grades: I and III; I and IV; II and IV. The results indicate that nuclear morphometry analysis is a simple and reproducible method that could be used to provide objective diagnostic criteria for cutaneous SCCs in the dog.

Immunohistochemical study of hormonal receptors and cell proliferation in normal canine mammary glands and spontaneous mammary tumours

The expression of hormone receptors and their relationship to cell proliferation in six samples of normal canine mammary tissue, and 11 benign and 10 malignant mammary neoplasms from female dogs were assessed by immunohistochemistry in formalin-fixed paraffin-embedded samples, by using monoclonal antibodies against progesterone and oestrogen receptors, and nuclear antigen Ki-67 (MIB-1). Malignant tumours negative for progesterone receptors proliferated at higher rates than progesterone receptor-positive tumours, suggesting that the progression towards malignancy in spontaneous mammary tumours is accompanied by a decrease in hormonal steroid dependency. Only one malignant tumour was positive for oestrogen receptors.

Ki-67 index as indicator of the post-surgical prognosis in feline mammary carcinomas

Forty-eight feline mammary carcinomas (FMC) were resected surgically from 48 cats to determine whether the Ki-67 index (Ki-67I) would provide an indication of the post-surgical survival time (PST). Twenty-four cats (50 per cent) were still alive (group A) one year after surgery, whilst 24 (50 per cent) (group B) had died. Formalin-fixed, paraffin wax-embedded histological sections were immunostained with a monoclonal antibody to Ki-67 (MIB-1) and at least 1000 nuclei in eight to 10 representative fields were counted. The Ki-67I was expressed as the percentage of positive nuclei. In FMC, the Ki-67I ranged from 7.5 to 49.7 (24.8+/-9.5). A statistically significant difference (P = 0.000006) in the Ki-67I was found between group A and group B cats. No other statistically significant differences were found between these groups. The Ki-67I did not correlate with age or different histological type, according to the WHO classification. A Ki-67I cut-off of 25.2 represents a useful tool for identifying FMC with a more aggressive course.

Prognostic value of nuclear morphometry in feline mammary carcinomas

This study of 30 cats with mammary carcinoma was designed to investigate the relationship between (1) six nuclear morphometric parameters (mean nuclear profile area [MNA], standard deviation of MNA [SDa], coefficient of variation of MNA [CVa], nuclear form factor (p2/4 pi area) [FF], standard deviation of FF [SDf], and coefficient of variation of FF [CVf]) assessed by image analysis, and (2) survival for > 1 year or < 1 year after surgical removal of the tumour. Only the SDf and the CVf appeared to be related to survival. Cats that died within 1 year had an SDf or CVf (or both) higher than the corresponding mean values (SDft and CVft) for all 30 cats; but only four of 16 cases (25%) with a SDf lower than SDft and five of 17 cases (29.4%) with a CVf lower than CVft died within 1 year. The authors conclude that SDf and CVf represent reliable prognostic parameters in feline mammary carcinomas.