Computer-Assisted Nuclear Morphometry in the Cytological Evaluation of Canine Perianal Adenocarcinomas

Quantitative Morphology as a Prognostic Factor in Feline Spontaneous Cutaneous Squamous Cell Carcinomas

In a study on cytological specimens from 30 cats with histologically confi rmed cutaneous squamous cell carcinoma, the morphometric variables mean nuclear area (MNA, μm2), mean nuclear perimeter (MNP, μm), mean nuclear diameter (D mean, μm), minimum nuclear diameter (D min, μm) and maximum nuclear diameter (D max, μm) were studied and compared to metastases in regional lymph nodes. The mean values of these parameters were signifi cantly greater in cats with lymph node metastases compared to parameters of tumour cells from cats which were lymph node-negative. A signifi cant positive correlation was observed between all studied morphometric parameters and metastases in the regional lymph nodes. In conclusion, computer -assisted nuclear morphometry could be used as a prognostic method in the diagnosis of spontaneous feline cutaneous squamous cell carcinomas.

Usefulness of cytologic criteria in ultrasound-guided fine-needle aspirates from subcentimeter canine mammary tumors

We determined cytologic features of histologically confirmed subcentimeter canine mammary tumors (CMTs) to determine reasonable criteria for an accurate cytologic diagnosis. Fifty-three CMTs from 28 bitches were included. All cytologic samples were collected by ultrasound-guided fine-needle aspiration biopsy, stained with May-Grünwald/Giemsa, and retrospectively evaluated using a scoring system established for 18 cytologic features. Mean nuclear area (MNA) was also measured for each sample by a computer-assisted program. Based on the histologic diagnosis, CMTs were divided into 2 groups: malignant tumors (25) and benign lesions (15). Data were statistically analyzed using Fisher and Mann–Whitney tests. Chromatin pattern ( p < 0.05) and macrophage infiltration ( p < 0.05) were significantly different between the groups. Median MNA was significantly ( p < 0.05) larger in malignant tumors. The evaluation of these cytologic features in subcentimeter CMTs may increase the sensitivity of cytology.

Evaluation of lymph node aspirates at diagnosis and relapse in dogs with high-grade multicentric lymphoma and comparison with survival time

BACKGROUND

Canine high-grade multicentric lymphoma, a common disease with variable response to chemotherapy, is often diagnosed using cytology.

OBJECTIVES

The purpose of the study was to compare cytologic features of canine peripheral lymph node aspirates collected at diagnosis and at relapse, and evaluate their usefulness in predicting survival.

METHODS

Cytologic scoring based on a rubric and nuclear morphometry analyses were performed on cytologic smears collected at diagnosis and at relapse. Scores at diagnosis and relapse were compared by paired t-test and evaluated in relation to time from diagnosis to remission, remission to relapse, relapse to death, and total survival time, using the Cox proportional-hazards regression model.

RESULTS

Number of mitoses and total cytologic score were significantly higher at relapse compared to diagnosis (P < .05). None of the nuclear morphometry measures were significantly different between diagnosis and relapse. The presence of binucleated or multinucleated cells at diagnosis was associated with a shorter remission and decreased total survival (P < .05). Increased mean nucleoli at relapse was associated with longer remission and total survival (P < .05). Increased minimum nuclear radius and diameter at diagnosis were associated with a decreased time from relapse to death (P < .05). Several nuclear morphometry measures at relapse were associated with a shorter time from diagnosis to remission (P < .05).

CONCLUSIONS

Number of mitoses and total score were higher at relapse than at diagnosis in canine lymphoma. The presence of binucleated or multinucleated cells at diagnosis may be useful as indicator of a poor prognosis. Further studies including a larger number of cases are required to reinforce the prognostic values of these cytologic features.

Evaluation of an anal sac adenocarcinoma tumor in a Spitz dog

A 9-year-old emasculated male Spitz with tenesmus and constipation had a subcutaneous mass at the left ventral aspect of the anus with history of polyuria and polydipsia. A complete blood cell count, serum biochemistry panel, and urinalysis (cystocentesis sample) were evaluated. Abnormalities in the serum biochemistry panel included a mildly elevated serum cholesterol concentration (7.28 mmol/L; reference interval, 2.70-5.94 mmol/L), increased serum alkaline phosphatase activity (184 U/L; reference interval, 9-90 U/L), alanine transaminase (122 U/L; reference interval, 5-60 U/L) activity and aspartate aminotransferase (80 U/L; reference interval, 5-55 U/L) activity, severe increased total calcium concentration (16.3 mg/dL; reference interval, 8.2-12.4 mg/dL or 9.3-11.4 mg/dL), and decreased total calcium concentration (3.4 mg/dL, reference interval, 2.5-5.6mg/dL). Furthermore, testing revealed an increased intact parathyroid hormone concentration (38.6 pmol/L; reference interval, 3-17 pmol/L). On cytologic and histopathologic examinations, various types of cells were observed. Most of the cells were oval to polygonal and had elliptical or elongate nuclei and a moderate amount of pale to basophilic cytoplasm. The remaining cells had round to oval nuclei and pale to basophilic cytoplasm. Cells of both types were loosely adhered to each other and were arranged in rosette-like structures. Both neoplastic cell types had fine homogenous chromatin and either a small indistinct nucleolus or no visible nucleolus. Mild anisokaryosis and anisocytosis were observed. Histologically, the mass consists of glandular structures formed by cuboidal cells admixed with bundles of spindle cells. Based on location and histologic features, the final diagnosis was adenocarcinoma of the apocrine gland of the anal sac, which should be included as a cytologic differential diagnosis when spindle cells and typical epithelial cells are observed in masses in the region of the anal sac of dogs.

Utility of nuclear morphometry in the cytologic evaluation of canine cutaneous soft tissue sarcomas

Cytopathologists lack reliable criteria to distinguish neoplastic from reactive spindle cells; however, with computer-based nuclear morphometry, it is now possible to more objectively and precisely quantify differences between selected populations of cells. Forty-four cutaneous soft tissue sarcomas and 5 cases of reactive spindle cell proliferations in the dog were morphometrically analyzed with regard to median and standard deviation (SD) of nuclear area, diameter (max, min, mean), radius (max, min), perimeter, and roundness. Overall, nuclei from reactive spindle cells were larger, with greater variation in nuclear size and shape. Significant differences ( P < 0.05) were found for several nuclear parameters, including the median and SD of maximum diameter and radius, as well as the SD of roundness. No significant differences were found in nuclear parameters between soft tissue sarcomas divided by histologic grade, mitotic index, or tumor necrosis score. Analysis of the sources of variation indicated near-perfect intraobserver and substantial interobserver agreement. The largest source of variation was due to selection of different measurement fields, reflecting the inherent biological variation in nuclear size within the tumor cell population. The results indicate that nuclear morphometry on cytologic preparations is a reproducible method that may be able to differentiate cutaneous soft tissue sarcomas from reactive mesenchymal lesions in the dog. Further studies, including a larger number of cases, are warranted to assess repeatability of results.

Association between anal sac gland carcinoma and dog leukocyte antigen-DQB1 in the English Cocker Spaniel

Anal sac gland carcinomas occur frequently in English Cocker Spaniels and, to a lesser extent, in other spaniel breeds. The disease typically presents in dogs aged 8 years or older and frequently metastasises to the local lymph nodes. The association between anal sac gland carcinoma in English Cocker Spaniels and the major histocompatibility complex class II loci (the dog leukocyte antigen loci DLA-DRB1, -DQA1, -DQB1) was investigated in 42 cases and 75 controls. Based on a corrected error rate of 0.017 for each test, the allele distribution in DLA-DRB1 showed no significant difference between cases and controls (P value = 0.019), while a significant difference was obtained for DLA-DQA1 and -DQB1 alleles (P values are 0.010 and 3.3 × 10⁻⁵). The DLA-DQB1*00701 allele was the most common in both cases and controls, but it had a higher frequency among the former (0.89) than in the latter (0.61), while the second most common allele had a higher frequency in the controls (0.23) than in the cases (0.07). Haplotype distributions were also significantly different between the two groups (P value = 1.61 × 10⁻⁴). This is the second disease in English Cocker Spaniels for which the most common DLA-DQB1 allele in the breed has been shown to have a higher frequency in cases than controls, while the second most common allele in the breed (*02001) has a significantly higher frequency in the controls, compared with the cases.