Comparison of B-mode and Doppler ultrasonographic findings with histologic features of benign and malignant superficial lymph nodes in dogs

OBJECTIVE: To compare and correlate B-mode and color Doppler ultrasonographic characteristics with histopathologic findings of benign and malignant superficial lymph nodes in dogs. STUDY POPULATION: 50 superficial lymph nodes that were normal, abnormally large on physical examination, or represented regional lymph nodes draining an area of suspected primary malignancy in 30 dogs. PROCEDURES: Before excision, lymph nodes were evaluated via B-mode and color Doppler ultrasonography to assess size, echogenicity, presence of a hilus, acoustic transmission, and vascular flow. Formalin-fixed, paraffin-embedded tissue sections of excised lymph nodes were stained with H&E and examined for the presence and extent of necrosis, fibrosis, fat, metastases, and tissue heterogeneity. To assess vascularity, the number and distribution of vessels stained by the Verhoeff van Gieson technique were recorded. RESULTS: In superficial lymph nodes, a varied echogenicity corresponded to tissue heterogeneity. The ultrasonographic detection of a hilus was associated with the presence of fibrous tissue, fat, or both in the hilar region. Acoustic enhancement corresponded to presence of areas of intranodal necrosis. There was significant correlation between both the distribution and the number of vessels detected via ultrasonography and that detected by histopathology. The amount of flow estimated via ultrasonography was typically higher than that estimated via histologic examination. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that histopathologic changes in canine lymph nodes have associated ultrasonographic changes and suggest that lymph node ultrasonography has an important role in the evaluation of lymph nodes in dogs in general and in dogs with neoplastic disease in particular.     

Correlation of histology of healed fractures and tissue surrounding implants with ultrasonographic and radiographic appearance

OBJECTIVES: To determine if there was histological correlation with ultrasonographic images of healed fractures and implant-associated tissue after fracture treatment by plate osteotomy. METHODS: Eight adult dogs were included in this retrospective study. Ultrasonography (B-mode and power Doppler) and radiography were performed before plate removal. Surgical biopsies were taken of the fracture site and the tissue adjacent to the plate. These were stained with haematoxylin and eosin to assess histomorphology and bone content and immunolabelled with CD31 to assess vascularity. RESULTS: Ultrasound and radiographic diagnoses of a healed fracture correlated with histological finding of bone healing. Ultrasonography and histology findings of vascularity were also highly correlated. The tissue surrounding the surgical implants was significantly more vascularised on both ultrasonography and histology than that at the fracture site itself. CLINICAL RELEVANCE: Ultrasonography can be used to diagnose fracture healing in plated fractures. Power Doppler ultrasonography examination of fracture healing should be performed away from surgical implants to avoid false-positive results of vascularisation.     

CHARACTERIZATION OF CANINE SUPERFICIAL TUMORS USING GRAY-SCALE B MODE, COLOR FLOW MAPPING, AND SPECTRAL DOPPLER ULTRASONOGRAPHY—A MULTIVARIATE STUDY

Superficial tumors are not routinely evaluated by two- or three-dimensional diagnostic imaging methods as part of the staging of canine cancer patients, although superficial tumors are readily imaged by ultrasound. The objectives of this study were to characterize the ultrasonographic patterns of superficial tumors and to evaluate whether ultrasound can help discriminate between benign and malignant tumors in dogs. Superficial tumors (n=132) in 86 dogs were evaluated by B mode, color flow mapping, and spectral Doppler ultrasonography. Size, echogenicity, tumor border definition, invasiveness, acoustic transmission, presence and distribution of vascular flow to and within the tumor, as well as perfusion indices were measured. The tumors were classified as lipomas, benign tumors, atypical mammary tumors, and malignant tumors. Multivariate statistics using discriminant analysis was used to determine which parameters may be used to predict the status of the tumor. Tumor echogenicity, border shape, acoustic shadowing, total number of vessels to the tumor and the total flow amount are the parameters that in combination resulted in the lowest classification error (24%), meaning that on average three out of four tumors were correctly classified using these parameters. All the lipomas and atypical mammary tumors were classified correctly by ultrasonography. The results of this study show that ultrasonography has an important role in the evaluation of canine superficial tumors, particularly in the evaluation of tissue homogeneity and tumor vascularity.     

Evaluation of nonunion fractures in dogs by use of B-mode ultrasonography, power Doppler ultrasonography, radiography, and histologic examination

OBJECTIVE: To investigate the use of ultrasonography to assess nonunion of fractures in dogs and to compare results of ultrasonography, radiography, and histologic examination. SAMPLE POPULATION: 8 nonunion fractures in 6 dogs (1 each in 5 dogs and 3 in 1 dog); dogs ranged from 7 to 94 months of age and weighed 6 to 30 kg. PROCEDURES: Diagnostic assessment consisted of complete clinical and orthopedic examinations, radiography, B-mode (brightness mode) ultrasonography, and power Doppler ultrasonography. Biopsy samples were obtained during surgery for histologic examination. They were stained with H&E and immunolabeled by use of anti-CD31 antibodies. Correlations of power Doppler score, power Doppler count, vessel area, and radiographic prediction with the mean number of vessels counted per hpf were derived. RESULTS: Radiographically, 7 of 8 nonunion fractures were diagnosed as atrophic and were therefore estimated to be nonviable. Vascularity of nonunion fractures during power Doppler ultrasonography ranged from nonvascularized to highly vascularized. Absolute vessel count during histologic examination ranged from 0 to 63 vessels/hpf; 5 nonunion sites had a mean count of > 10 vessels/hpf. Vascularity during power Doppler ultrasonography was highly correlated with the number of vessels per hpf, whereas the correlation between the radiographic assessment and histologic evaluation was low. CONCLUSIONS AND CLINICAL RELEVANCE: Radiographic prediction of the viability of nonunion fractures underestimated the histologically assessed vascularity of the tissue. Power Doppler ultrasonography provided a more accurate estimation of the viability of the tissue and therefore the necessity for debridement and autografts during revision surgery.     

ULTRASONOGRAPHIC APPEARANCE OF JEJUNAL LYMPH NODES IN DOGS WITHOUT CLINICAL SIGNS OF GASTROINTESTINAL DISEASE

The jejunal lymph nodes of 57 dogs without clinical signs of gastrointestinal disease were examined to characterize their ultrasonographic appearance on B-mode and power Doppler examination, and to obtain ultrasonographic measurements. The lymph nodes were mildly hypoechoic to the mesentery in 71% of dogs and isoechoic in 29%. All dogs, 6 years of age or older had jejunal lymph nodes of uniform echogenicity. In dogs less than 6 years of age, nonuniform lymph nodes with different echopatterns were observed. Although most lymph nodes had no blood flow based on power Doppler examination, hilar blood flow was detected in 33% of dogs, which were generally less than 2 years of age. The median maximum thickness of the jejunal lymph nodes was 3.9 mm (range 1.6–8.2 mm), and their median maximum width 7.5 mm (range 2.6–14.7 mm). There was a significant correlation between larger lymph node diameter and younger age and higher body weight. We concluded that patient age should be considered when interpreting the echopattern and vascularity of jejunal lymph nodes in dogs, and that the jejunal lymph nodes of dogs without clinical signs of gastrointestinal disease may exceed the previously stated upper limit of 5–6 mm thickness.     

Evaluation of quantified contrast-enhanced color and power Doppler ultrasonography for the assessment of vascularity and perfusion of naturally occurring tumors in dogs

OBJECTIVE: To investigate subjective and computerized methods of evaluation of color Doppler (CD) and power Doppler (PD) ultrasonographic images (obtained before and after administration of contrast medium) for quantitative assessment of vascularity and perfusion of various naturally occurring tumors in dogs. SAMPLE POPULATION: 34 tumors in 34 dogs. PROCEDURE: Tumors in dogs were examined via CD and PD ultrasonography before and after i.v. injection of a microbubble contrast agent (pre- and postcontrast examinations, respectively). Images were digitized for subjective assessment of vessel density and vascular pattern and computer-aided assessment of parameters of vascularity (fractional area [FA]) and perfusion (color-weighted FA [CWFA] and mean color-weighted FA [CWFA] and mean color level). RESULTS: With both analysis methods, more vessels were identified in precontrast PD ultrasonographic images than in precontrast CD ultrasonographic images. Moreover, compared with values for precontrast PD ultrasonography, FA, CWFA, and mean color level were higher for postcontrast PD ultrasonography. In postcontrast images, there was a significant association between vessel densities determined through subjective and computerized assessments. Although sample size was small, vascularity of squamous cell carcinomas was significantly greater than that of other tumor types. Ten of the 19 softer than issue that sarcomas had low vessel density with minor contrast enhancement. With increasing gross tumor volume, FA and CWFA decreased for all Doppler ultrasonographic methods. CONCLUSIONS AND CLINICAL RELEVANCE: Higher values of the ultrasonographic parameters representing vascularity and perfusion of tumors in dogs were determined via PD ultrasonography after administration of contrast medium than via PD or CD ultrasonography without administration of contrast medium.     

Ultrasonographic features of testicular neoplasia in dogs: 16 cases (1980-1988)

For 16 dogs with testicular neoplasia (n = 19 tumors), ultrasonography was performed to determine whether a correlation exists between ultrasonographic features of testicular tumors and cell type. The echogenicity of the tumors varied depending on the size of the tumor and whether the tumor had focal or diffuse distribution within the testis. The ultrasonographic characteristics of Sertoli cell tumors were variable, with no predominant pattern. This variation may be related to tumor size, because 6 of 7 Sertoli cell tumors were greater than 5 cm in diameter. Focal seminomas and interstitial cell tumors less than 3 cm in diameter had hypoechoic texture. Focal seminomas and interstitial cell tumors greater than 3 cm in diameter had mixed echogenicity. Tumors of multiple cell types were greater than 5 cm in diameter and had mixed echogenicity. In valuable breeding dogs with a small (less than 3 cm) focal intrascrotal lesion, testicular ultrasonography would be of benefit for localization of the mass to the testis or epididymis for subsequent biopsy. In dogs with intraabdominal neoplastic testes, ultrasonography may be of benefit in determining intra-abdominal metastases and invasion of contiguous structures.     

Sonographic characteristics of presumptively normal main axillary and superficial cervical lymph nodes in dogs

Objective-To evaluate the B-mode and Doppler ultrasonographic appearance of presumptively normal main axillary and large superficial cervical lymph nodes (MALNs and SCLNs, respectively) in adult dogs. Animals-51 healthy adult dogs (data from 1 dog were not analyzed). Procedures-For each dog, weight, distance from the cranial aspect of the first sternebra to the caudal aspect of the left ischiatic tuberosity, and thoracic height and width at the level of the xiphoid process were recorded. Via B-mode and Doppler ultrasonography, echogenic characteristics, size in relation to body size and weight, and vascular supply of the MALNs and the SCLNs were evaluated (1 SCLN in 1 dog was not ultrasonographically visible). Results-Most MALNs were clearly margined, solitary, and ovoid; echopatterns were homogenous or cortical and hypo- to isoechoic, compared with surrounding soft tissues. Size measurements of MALNs correlated with dogs' body length, thoracic width and height, and body weight. Most SCLNs were clearly margined, fusiform, and hypoechoic (compared with surrounding soft tissues) with a cortical or homogenous echopattern. Size measurements of SCLNs correlated with dogs' body length, thoracic width and height, and body weight. In 50 of the 100 MALNs, an intranodal vascular supply was detected; in contrast, an intranodal vascular supply in SCLNs was detected infrequently. Conclusions and Clinical Relevance-Results indicated that, in dogs, anatomically separate lymph nodes have different echogenic and vascular characteristics; body size (skeletal length, height, and width), along with body weight, were correlated with sizes of presumptively normal MALNs and SCLNs.     

B‐Mode and Doppler Sonography of the Mammary Glands in Dairy Goats for Mastitis Diagnosis

This study aimed to evaluate the sonographic characteristics of the udder and teats and to determine the Doppler indexes of mammary artery in healthy and undergoing subclinical and clinical mastitis goats. Thirty animals among Saanen and Alpine Brown goats were arranged in three groups, healthy goats (HG), goats with subclinical mastitis (SMG) and goats with clinical mastitis (CMG). Using the B‐mode, the sonographic characteristics (echotexture and echogenicity) and biometry (diameter and area of the udder cistern, diameter and area of the teat cistern and thickness of the teat wall) were evaluated. Using Doppler ultrasonography, the vascular indexes of the mammary artery were obtained. It was observed hyperechogenicity with solid component in the gland cistern when comparing animals with clinical mastitis and healthy mammary tissue. Regarding the echotexture of the breast tissue, there was heterogeneity in the mammary parenchyma on the three groups, for the milk, it was observed homogeneity for animals on HG and SMG and heterogeneity for animals on CMG. Grey‐scale quantitative assessment revealed increase in echogenicity (mean value) for all the structures when comparing the three groups. Biometry did not reveal statistical difference between groups, for none of the evaluated structures. Doppler examination of the mammary artery showed the decrease of end diastolic velocity and raise of pulsatility index between groups. The association of B‐mode and Doppler ultrasonography is useful for the evaluation of the udder of dairy goats with mastitis. It is a sensitive and specific method for the study of this disease. Doppler mode was unable to establish reliable criteria for diagnosis of subclinical mastitis. Moreover, the quantification of echogenicity is a useful technique for the evaluation of the milk in animals with mastitis; therefore, it is suggested that it can be used as complementary technique for the diagnosis of mastitis in goats.     

CHARACTERIZATION OF NORMAL AND ABNORMAL CANINE SUPERFICIAL LYMPH NODES USING GRAY-SCALE B-MODE, COLOR FLOW MAPPING, POWER, AND SPECTRAL DOPPLER ULTRASONOGRAPHY: A MULTIVARIATE STUDY

The objective of this study was to characterize the ultrasonographic patterns of normal superficial lymph nodes and to evaluate whether ultrasonography can help discriminate between different lymphadenopathies (reactive, lymphoma, and metastases) in dogs. Three hundred and eighteen superficial lymph nodes in 142 dogs were studied by B-mode, color flow mapping, power, and spectral Doppler ultrasonography. Size, echogenicity, nodal border definition, presence of a nodal hilus, acoustic enhancement and distribution of vascular flow, as well as perfusion indices were measured. Multivariate statistics using discriminant analysis was used to determine which parameters can be used to predict the diagnosis of the lymph node. The size of the lymph node, distribution of vascular flow within the lymph node, and pulsatility index (PI) in combination gave a classification error of 23% for the four groups of lymph nodes. This was improved to 11% if the nodes were divided into two groups: benign and malignant. There was a significant difference in resistive index (RI) and PI between benign and malignant nodes. Cut-off values were determined using receiver operator curves, 0.68 RI and 1.49 PI.     

Ultrasonographic assessment of the feline mammary gland

The aim of this study is to characterise the feline mammary echotexture using B-mode ultrasonography, which is not routinely used to examine the feline mammary gland. Using a 5-9 MHz linear transducer the ultrasonographic appearance of non-stimulated and stimulated mammary glands was determined in 35 mature intact non-pregnant, pregnant and lactating queens aged from 16 months to 8 years. In intact non-pregnant queens, mammary glands are fairly underdeveloped and on the ultrasonograms they appear with a regular hypoechoic texture and generally show a thickness of less than 2.0mm. The stimulated mammary tissue typically presents a more hyperechoic appearance compared to the non-stimulated gland and a fine granular echotexture. Maximum echogenicity of the mammary gland is reached during lactation. In late pregnancy, the mammary glands reach 6-9 mm in thickness. During lactation, the size of the glands depends on the existence of a suckling stimulus, with the suckled glands reaching about 11 mm in thickness. Ductal structures can only be imaged during late pregnancy and lactation. Ultrasonographic evaluation of the feline mammary gland can become a valuable diagnostic tool to characterise physiological changes and may further contribute to a better characterisation of diseased mammary tissue.     

High-frequency ultrasonography of the skin of clinically normal dogs

OBJECTIVE: To assess the applicability of high-frequency diagnostic ultrasonography for evaluation and accurate measurement of the skin thickness of clinically normal dogs. ANIMALS: 26 healthy dogs (12 sexually intact males, 13 sexually intact females, and 1 spayed female) of various breeds and ages. PROCEDURE: Ultrasonographic examination of the skin and histomorphometric analysis of skin biopsy specimens obtained from the same site were performed. A 13-MHz linear-array transducer was used to obtain a series of ultrasonographic images of the skin in the flank region; images were analyzed and measured by use of imaging software. Cutaneous biopsy specimens were placed in fixative and then stained with H&E and Masson trichrome stains. Histomorphometric analysis was performed by use of an image analyzer. Thickness of the epidermis and dermis of each specimen was evaluated by use of a semiautomatic procedure of quantification. Data obtained from ultrasonographic and histologic measurements were compared by use of the Pearson correlation test. RESULTS: The ultrasonographic pattern of canine skin was consistently characterized by 3 distinct, defined echogenic layers corresponding to the epidermal entry echo, epidermis and dermis, and subcutaneous tissues. A positive correlation was found between ultrasonographic and histologic measurements of skin thickness. CONCLUSIONS AND CLINICAL RELEVANCE: Comparison between ultrasonographic and histologic appearance of the skin revealed that layering of canine skin (ie, epidermis and dermis) and the subcutaneous tissues may be recognized and measured by use of high-frequency ultrasonography. Thus, diagnostic ultrasonography may be a useful tool for the noninvasive evaluation of cutaneous disorders in dogs.     

Transcranial Doppler sonographic findings in granulomatous meningoencephalitis in small breed dogs

Granulomatous meningoencephalitis (GME) is an acute, progressive, and often fatal inflammatory disease of the central nervous system, affecting mainly small and toy dog breeds. A definitive diagnosis of GME can only be achieved through histopathologic examination of samples collected after death. This retrospective study describes transcranial Doppler ultrasonography (TDS) findings in dogs with confirmed clinical histopathology of GME. Eleven dogs were selected for this study. Sonographic findings in B-mode demonstrated diffuse decreased brain parenchyma echogenicity in 9 dogs, ventriculomegaly in 8 dogs, brain atrophy in 4 dogs, and hyperechoic focal lesions in 6 dogs. Color Doppler imaging revealed more obvious vessels of the arterial circle in 10 dogs. Spectral Doppler examination was performed in 10 dogs to detect the 6 major cerebral arteries of interest. The examination showed normal and high resistive index (RI) values in the outlined arteries. The TDS findings were consistent with pathology found on postmortem examination.     

Serum alkaline phosphatase isoenzyme activities in canine malignant mammary neoplasms with and without osseous transformation

BACKGROUND: Increased serum activity of total alkaline phosphatase (TALP) has been found in dogs with mammary neoplasms, especially malignant mixed tumors. We hypothesized that the bone isoenzyme of alkaline phosphatase (BALP), a specific indicator of osteoblastic activity and bone formation, may contribute to increased TALP in dogs with mammary neoplasms with osseous transformation. OBJECTIVE: The purpose of this study was to compare serum TALP, BALP, and other ALP isoenzyme activities in dogs with mammary malignant neoplasms with and without osseous transformation. METHODS: Twenty-one female dogs with malignant mammary neoplasms were compared with 21 clinically healthy, age-matched female control dogs. Physical, clinicopathologic (including preprandial and postprandial serum bile acids, ACTH stimulation, and low-dose dexamethasone suppression tests), radiographic, and ultrasonographic examinations were performed on all dogs with tumors to assess coexisting conditions. On the basis of histologic examination of excised tumors, dogs were further classified as having epithelial (n = 11) or mesenchymal/mixed (epithelial-mesenchymal) (n = 10) neoplasms, the latter of which had histologic and radiologic evidence of bone formation. Serum TALP, BALP, liver alkaline phosphatase (LALP), and corticosteroid-induced alkaline phosphatase (CALP) activities were measured using biochemical methods. RESULTS: Dogs with malignant mammary tumors had significantly higher (P < .05) median serum TALP (170 U/L), BALP (59 U/L), LALP (49 U/L), and CALP (24 U/L) activities, compared with control dogs (81, 32, 37, and 5 U/L, respectively). Significantly higher activities of BALP and LALP were found in dogs with epithelial neoplasms; whereas, only CALP activity was higher in dogs with mesenchymal/mixed neoplasms. There was no significant difference in TALP or isoenzyme activitities between epithelial and mesenchymal/mixed groups. CONCLUSION: BALP activity is increased in some dogs with malignant mammary tumors but does not account for the increase in TALP in dogs with neoplasms that have osseous transformation.     

Cytologic examination of fine‐needle aspirates from mammary gland tumors in the dog: diagnostic accuracy with comparison to histopathology and association with postoperative outcome

Background: Mammary tumors are the most common neoplasms in female dogs. Malignant tumors may carry a poor prognosis and necessitate surgery. Few data are available on the value of cytologic examination as a diagnostic or prognostic tool for mammary tumors in dogs. Objectives: The objectives of this study were to determine whether cytologic findings in fine‐needle aspirate specimens of canine mammary tumors correlate with histopathologic results and whether the cytologic diagnosis is associated with postoperative outcome. Methods: In this prospective study, fine‐needle aspirate samples were obtained from 50 mammary tumors in 50 dogs. Results of cytologic and histopathologic examination were compared, using the histologic diagnosis as the reference method. Kaplan–Meier log rank analysis was used to evaluate univariate association of the cytologic diagnosis with duration of survival, local control, and metastasis‐free interval. Results: Adequate cytologic samples were obtained in 43/50 (86%) cases. The cytologic diagnosis correlated with the histologic diagnosis for benign and malignant tumors in 40/43 (93%) and 35/43 (81%) cases, respectively. Cytologic examination had a sensitivity of 88% and a specificity of 96% for the diagnosis of malignancy. The cytologic diagnosis had significant univariate association with duration of survival (P=.016), recurrence‐free interval (P=.003), and metastasis‐free interval (P=.014). Conclusions: Cytologic examination of mammary tumors in the dog has satisfactory accuracy, sensitivity, and specificity for the diagnosis of malignancy and is associated with postoperative outcome. Further studies on the diagnostic accuracy of cytology as well as multivariate analysis of its preoperative prognostic value in mammary tumors in the dog are warranted.     

Immunocytochemical study of Ki-67 as a prognostic marker in canine mammary neoplasia

Background: Canine mammary tumors are challenging for clinicians and pathologists because of complex histologic classification, low specificity of cytologic diagnosis, and unpredictable biological behavior. In histologic specimens, expression of tumor proliferation marker Ki‐67, a nuclear nonhistone protein, has been shown to have prognostic value for canine mammary tumors and to correlate with malignancy and low survival rates. Objective: The objective of this study was to measure the proliferation index of canine mammary tumors by immunochemical detection of Ki‐67 in cytologic specimens and to determine its relationship to clinical and pathologic variables and patient outcome. Methods: Spontaneous mammary tumors from 31 female dogs were surgically excised. Imprint specimens for cytologic evaluation were wet‐fixed in ethanol; histologic specimens were prepared routinely. Immunostaining was performed with the PH 177 monoclonal antibody against Ki‐67; proliferation index was graded from negative to +++. Dogs were followed for 18 months. Multivariate logistic regression analysis was used to determine correlations between immunocytochemical results, tumor and clinical variables, and patient outcome. Results: Ki‐67 proliferation indices in cytologic specimens were significantly lower for nonmalignant tumors than for malignant tumors. High index values of Ki‐67 were positively correlated with metastasis, death from neoplasia, low disease‐free survival rates, and low overall survival rate. With the exception of 4 specimens for which cellularity was insufficient, positive expression of Ki‐67 in cytologic specimens correlated with that of histologic specimens. Conclusions: The prognostic value of the Ki‐67 index in canine mammary tumors by using wet‐fixed cytology imprint specimens was similar to that observed previously for histologic specimens. Immunocytochemical detection of Ki‐67 could improve the accuracy and value of cytology by providing safe and rapid information about malignancy and patient outcome.     

ULTRASONOGRAPHIC FEATURES OF CANINE GASTROINTESTINAL STROMAL TUMORS COMPARED TO OTHER GASTROINTESTINAL SPINDLE CELL TUMORS

Canine gastrointestinal stromal tumors (GISTs) are a recent subtype of gastrointestinal spindle cell tumor recognized with the increasing use of immunohistochemistry. To our knowledge, no imaging features have been described in immunistochemically confirmed canine GISTs. The objective of this retrospective, cross‐sectional study was to describe ultrasonographic features of canine GISTs compared with other spindle cell tumors. Thirty‐seven dogs with an ultrasonographically visible gastrointestinal mass and a histopathologic diagnosis of spindle cell neoplasia were examined. Immunohistochemistry staining was performed for retrieved tissue samples to further differentiate the tumor type and each sample was interpreted by a single veterinary pathologist. Ultrasonographic features recorded examined included mass echogenicity, homogeneity, presence of cavitation, layer of origin, bowel wall symmetry, and loss of wall layering, location, size, vascularity, and evidence of perforation or ulceration. Tumor types included 19 GISTs, eight leiomyosarcomas, six leiomyomas, and four nonspecified sarcomas. Gastrointestinal stromal tumors were significantly more likely to be associated (P < 0.03) with abdominal effusion than other tumor types. There was overlap between the anatomical locations of all tumors types with the exception of the cecum where all eight tumors identified were GISTs. Besides location, there were no unique ultrasound features of GISTs that would allow distinction from other gastrointestinal spindle cell tumors. Similar to previous studies, GISTs appeared to be the most common spindle cell tumor associated with the cecum in our sample of dogs. The high frequency of abdominal effusion with GIST's was of unknown etiology could possibly have been due to septic peritonitis.     

Lectin histochemistry on squamous metaplasia in different epithelial tumors of dogs.

Biotinylated lectins and avidin-biotin-peroxidase complex were used to study the correlation between cellular glycoconjugates' expression and squamous maturation in normal canine skin and in various epithelial neoplasms. Normal skin tissue was obtained from five, male, random-source dogs, 5 to 7 years old. The tumors tested, selected from the files of our Department, were fifteen squamous cell carcinomas from different tissue origin, five hepatoid perianal gland adenocarcinomas with squamous metaplasia, and fourteen solid mammary carcinomas with and without histologic evidence of squamous metaplasia. Except for mammary gland carcinomas, all tumors had been surgically excised from male dogs. Intermediate filament aggregation of twelve solid mammary gland carcinomas were studied electron microscopically. The basal and the lower spinous cells in normal skin and the less differentiated cells in squamous cell carcinomas stained moderately with Griffonia simplicifolia agglutinin-I. Spinous and granular cell layers stained strongly with Phytolacca americana mitogen and Arachis hypogaea agglutinin. Both lectins stained well-differentiated cells in squamous cell carcinomas. The electron microscopic study carried out in solid carcinomas of mammary glands revealed some relationship between the presence of intracytoplasmic tonofibrils and the binding of Griffonia simplicifolia agglutinin-I and Phytolacca americana mitogen to the tumors tested. Our results suggest that the glycosylation pattern occurring during normal keratinocyte differentiation is conserved in squamous cell carcinomas and that Griffonia simplicifolia agglutinin-I and Phytolacca americana mitogen may represent useful tools in distinguishing poorly differentiated squamous cell carcinomas from other poorly differentiated mammary epithelial tumors.     

Telomere length and telomerase activity in canine mammary gland tumors

OBJECTIVE: To measure telomere length and telomerase activity in naturally occurring canine mammary gland tumors. SAMPLE POPULATION: 27 mammary gland tumor specimens obtained during resection or necropsy and 12 mammary gland tissue specimens obtained from healthy (control) dogs. PROCEDURE: Telomere length in tissue specimens was measured by use of restriction endonuclease digestion and Southern blot analysis. Telomerase activity was measured by use of a telomeric repeat amplification protocol assay. RESULTS: Telomere length in mammary gland tumors ranged from 11.0 to 21.6 kilobase pairs (kbp; mean +/- SEM, 14.5+/-0.5 kbp) but did not differ among tumor types. Telomeres in mammary gland tumors were slightly shorter than in normal tissue specimens, but telomere length could not be directly compared between groups, because mean age of dogs was significantly different between groups. Age was negatively correlated with telomere length in control dogs but was not significantly correlated with length in affected dogs. Telomerase activity was detected in 26 of 27 mammary gland tumors and in 4 of 12 normal tissue specimens. However, telomerase activity and telomere length were not correlated in tumor specimens. CONCLUSIONS AND CLINICAL RELEVANCE: Telomere length is maintained in canine mammary gland tumors regardless of the age of the affected dog. Measurement of telomere length may be a useful tool for monitoring the in vivo effects of telomerase inhibitors in dogs with tumors.