[Retropharyngeal manifestation of T-cell-rich B-cell lymphoma in a 7-year-old Icelandic gelding]

A 7-year-old Icelandic gelding was presented with acute severe dyspnea of one day duration and purulent nasal discharge that had been present for 6 weeks. Clinically, the initial examination focused on severe enlargement of the mandibular and retropharyngeal lymph nodes as well as a mixed dyspnea.The diagnosis of a malignant lymphoma was evident following laboratory diagnostics, endoscopy, and cytological examination of a fine needle aspiration of a mandibular lymph node. The gelding was euthanized due to the poor prognosis and a significantly disturbed general condition. Pathohistological examination revealed a multicentric T-cell-rich B-cell lymphoma.

Fluoroscopy-guided fine-needle aspiration of deep-seated pulmonary masses in dogs and cats appears safe and accurate

OBJECTIVE

Deep-seated pulmonary lesions can be difficult to sample safely. The objective of this study was to determine the relative safety and accuracy of fluoroscopy-guided fine-needle aspiration of deep-seated pulmonary lesions regardless of their size and depth.

ANIMALS

Client-owned animals; 5 dogs and 5 cats.

CLINICAL PRESENTATION

Pulmonary lesion locations were determined on dorsoventral and lateral views using fluoroscopy. The lateral thoracic wall was aseptically scrubbed, and an indelible marker was used to mark the point of entry of the needle for sampling. The path of a 22-gauge needle attached to a syringe was followed using fluoroscopic guidance. Mass volume (Vma) and distance from skin and pleura to lesion (DSK-L and DPL-L) were recorded.

RESULTS

In dogs, mean Vma was 137.2 cm3 (range, 6.3 to 426.2 cm3). Mean DSK-L was 71 mm (range, 37 to 101 mm) and DPL-L was 33 mm (range, 16 to 71 mm). Exfoliative cytology results were consistent with carcinoma in 4 dogs and lymphoma in 1 dog. A minor postprocedural complication was noted in 1 dog. In cats, the mean Vma was 2.4 cm3 (range, 1.6 to 3.7 cm3). Mean DSK-L was 42 mm (range, 20 to 75 mm) and DPL-L was 21 mm (range, 12 to 32 mm). Cytology results were consistent with pulmonary carcinoma in 2 cats, inflammation in 2 cats, and necrotic debris in 1 cat.

CLINICAL RELEVANCE

Fluoroscopy-guided fine-needle aspiration of pulmonary masses is a safe and accurate technique to obtain cytologic samples irrespective of the size and depth of the lesions.

Extracardiac adult-type rhabdomyoma-Report of two cases in dogs

This report describes the cytologic, histopathologic, and immunohistochemical features of adult-type rhabdomyoma located within the subcutaneous tissue in a 14-year-old female Border Collie (thigh) and a 13-year-old male Mongrel (flank). In both cases, fine-needle aspiration biopsy revealed cluster-forming, epithelial-like polygonal cells with abundant foamy cytoplasm, and moderate to marked anisocytosis and anisokaryosis; therefore, an epithelial tumor was suspected. After surgical excision, tumors underwent histopathologic examination with additional immunohistochemistry. Both tumors were well-demarcated and located within the subcutaneous tissue in the vicinity of the cutaneous muscle. The tumor mass consisted of densely packed round or polygonal cells with distinct vacuolation of the cytoplasm. Tumor cells expressed vimentin, desmin, and NSE and were cytokeratin and α-SMA negative. Based on histologic features and immunophenotyping, adult-type rhabdomyoma was diagnosed in both cases. This study highlights that the cytologic features of rhabdomyoma can be misleading and may suggest an epithelial tumor.

An immersive simulation strategy to teach cytology sample collection methods and basic diagnosis skills: A two academic center study

BACKGROUND

Collecting cytology samples and making simple diagnoses are skills taught in veterinary universities, mostly in a passive way. Simulators enhance practical skills learning, increasing student engagement through immersive activities. These strategies have not been carefully assessed in veterinary cytology.

OBJECTIVES

This study aimed to describe a simulator developed for training cytology sample collection methods and assess the utility of an immersive simulation strategy to learn and practice the collection of cytology samples.

METHODS

A flipped classroom with a station design was followed. Students first watched video tutorials on sampling collection, listened to brief cases' clinical histories, and moved to immersive simulator stations. There, they practiced imprints, swabs, and fine-needle aspiration (FNA). Microscopic observation of the material was available through augmented reality tools. Students were evaluated by Objective Structured Clinical Examination (OSCE) tools on their ability to perform FNA on stuffed animal models. Students answered two questionnaires addressing their learning outcomes.

RESULTS

Second- and third-year students from two centers (n = 129) practiced cytologic collection methods in simulators which significantly changed their willingness to perform FNA in live animals after the class activities. OSCE pass rates over 90% were obtained for most steps of FNA, and students rated the activity as essential/very relevant for learning.

CONCLUSIONS

Immersive simulation strategies were effective at increasing student comfort with cytologic sampling techniques. This approach should be included in the veterinary curriculum as it can increase the quality of cytology samples and could potentially improve the cytologic diagnosis of a submitted sample.

Cytologic, histopathologic, and immunohistochemical features of keloidal fibroma in a dog

A five-year-old male English Bulldog was presented with a firm, well-circumscribed, 1 cm in diameter cutaneous mass on the left flank. Fine-needle aspiration (FNA) biopsy samples were collected for cytologic analysis. Cytology revealed a highly cellular sample consisting of spindle cells, numerous bundles of thick, glassy eosinophilic material (hyalinized collagen), and inflammatory cells. Spindle cells showed moderate anisocytosis and anisokaryosis, had oval nuclei with coarsely stippled chromatin, 1-3 prominent round nucleoli, and moderate amounts of wispy cytoplasm. Cells were occasionally associated with an eosinophilic extracellular matrix. Binucleated and trinucleated spindle cells were often noted. Low numbers of macrophages, small lymphocytes, and individual well-granulated mast cells were also present. The lesion was excised and submitted for histopathologic examination, revealing a well-delineated, nonencapsulated mass composed of hyalinized collagen fibers separated by spindle-shaped mesenchymal cells in the deep dermis and subcutis. Mild anisocytosis and anisokaryosis and less than one mitosis per 10 × high power fields were present. Excision of the mass was complete. The findings were consistent with a keloidal fibroma, a rare benign variant of fibroma. Neoplastic cells showed positive immunoreactivity for vimentin, and a small-to-moderate number of tumor cells showed positive immunoreactivity for α-smooth muscle actin. This is the first cytologic description of a keloidal fibroma correlated with histopathologic findings and immunolabeling. In cases where keloidal neoplasia is suspected, and since moderate cellular atypia can be present on cytologic examination even in cases of keloidal fibroma, histopathologic examination is necessary to differentiate between keloidal fibroma and keloidal fibrosarcoma.

Characterization of alkaline phosphatase cytochemistry in canine neoplastic and non-neoplastic pulmonary mass aspirates

BACKGROUND

Distinguishing primary and secondary pulmonary neoplasms can be challenging via cytology, and a rapid, inexpensive diagnostic tool to differentiate these neoplasms is unavailable. Alkaline phosphatase cytochemistry (ALP-CC) has been used to identify primary pulmonary carcinomas in human patients, and we hypothesized it could be applied to canine lung aspirates.

OBJECTIVE

We aimed to characterize ALP-CC expression in fine-needle aspirate (FNA) samples of canine pulmonary neoplastic and non-neoplastic tumors.

METHODS

A retrospective case search was conducted to identify cases with contemporaneous cytology and histopathology reports from pulmonary lesions, including neoplastic and non-neoplastic etiologies. Slides prepared from pulmonary aspirates were stained for ALP-CC activity, and the percentage of ALP-CC-positive primary pulmonary epithelial tumors was determined. To characterize the ALP-CC expression in non-neoplastic cellular constituents of pulmonary FNA samples, mesothelial cells were also evaluated.

RESULTS

Forty-eight canine cases met the inclusion criteria. ALP-CC-positive cells were seen in both neoplastic and non-neoplastic lesions. In non-neoplastic lesions, pulmonary epithelial cells were ALP-CC positive. Eighty-nine percent of primary pulmonary epithelial neoplasms were ALP-CC positive, and no ALP-CC positivity was noted in mesothelial cells. ALP-CC-positive neoplastic cells were seen in a metastatic amelanotic melanoma.

CONCLUSIONS

Primary pulmonary epithelial neoplasms are frequently ALP-CC positive, but such positivity is not restricted to this tumor type. Non-neoplastic pulmonary epithelial cells can be ALP-CC positive, whereas mesothelial cells are negative.

Comparison of fine-needle aspiration techniques

BACKGROUND

Fine-needle aspiration (FNA) has been reported since 1912 beginning with the use of trocars and other specialized instruments that were impractical. Since then, FNA has proven to be a successful alternative technique to excisional biopsy for some assays despite a few limitations.

METHODS

In this study, we compared four different techniques for FNA in rhesus macaques by evaluating total live cells recovered and cell viability using a standard 6 mL syringe and 1.5-inch 22-gauge needle.

RESULTS

Technique B which was the only technique in which the needle was removed from the syringe after collection of the sample to allow forced air through the needle to expel the contents into media followed by flushing of the syringe and needle resulted in the highest total cell count and second highest cell viability in recovered cells.

CONCLUSION

Based on our results, Technique B appears to be the superior method.

Survey of the Clinical, Cytological, and Histopathological Features Associated with Neoplasms in Captive Avian Species in Melbourne, Australia

Over a 3.5-year period, tissue samples from 141 companion and aviary birds with clinically suspected, naturally occurring solid neoplasms were collected via surgical biopsy (n = 53) or at necropsy examination (n = 88) from a population of birds presenting to an avian veterinary clinic in Melbourne, Australia. Neoplastic processes were identified in 73.7% (n = 104) of samples, with 83.7% (n = 87) being interpreted as malignant neoplasia and 16.3% (n = 17) being interpreted as benign neoplasia. The overall estimated prevalence of neoplasia in the study population (n = 5125) was 2.45% (95% confidence interval, 2-2.97%). The gastrointestinal and reproductive tracts were the most commonly affected systems. The most common presenting signs were nonspecific and included lethargy, coelomic distension, and inappetence. In 59 cases, fine-needle aspirates (FNAs) and impression smears were also obtained and evaluated cytologically. The accuracy of cytology for detecting neoplasia in birds and for determining whether a neoplastic process was benign or malignant was assessed by using histopathology as the "gold standard." There was complete agreement between the cytological and histopathological diagnoses in 72.8% (43/59) of cases. Cytology correctly identified 87.5% of these cases (35/40) as malignant neoplasms and 55.6% (5/9) as benign processes. There was no significant difference between the use of cytology and histopathology for the detection of malignant neoplasia in birds (P = 0.185). The accuracies of FNAs and impression smears for examining avian tumors were also compared. Overall, the best cell preservation was obtained by performing impression smears from tissues, with 62.2% (n = 28) returning high cellularity for cytological examination, compared to 53.8% (n = 14) when samples were obtained by FNA. This study provides an overview of the types and prevalence of neoplasms in a captive bird population from Australia, correlates physical examination findings with tumor types, and provides evidence that cytology is a reliable preliminary diagnostic tool for detecting neoplasia in birds.

Ultrasonographic diagnosis of a lymphomatous lymph node presumptively infiltrating the ureter causing hydronephrosis in a 3-year-old dog

A 3-year-old male neutered mixed breed dog was presented for chronic vomiting and diarrhea. Abdominal ultrasound revealed a large amorphous, heterogeneous mass within the left mid to caudal abdomen most consistent with medial iliac lymph node. It appeared to invade the left ureter and extend distally causing ureteral obstruction and hydronephrosis. Concurrent additional ultrasound findings were consistent with metastatic or multicentric neoplasia. Fine needle aspirates of the lymph node and spleen both confirmed large cell lymphoma. These findings present evidence of lymphoma invading directly from an organ into the ureter which has not previously been reported in dogs.

Diagnostic utility of ultrasound-guided fine-needle aspiration and needle-core biopsy sampling of canine splenic masses

This prospective clinical study sought to determine the accuracy of cytopathologic examination and needle-core biopsy (NCB) against diagnoses obtained by excisional histopathology (EH) for canine splenic masses. Twenty-five masses were evaluated ex vivo by ultrasound-guided fine-needle aspiration (FNA) and NCB tissue sampling. Each spleen was placed in a container and artificial skin placed over its surface. Ultrasound-guided FNA using a 22-gauge needle and 2 NCB samples [14-gauge (NCB-14), 16-gauge (NCB-16)] were obtained and submitted for analysis. Results were compared to results obtained by splenic excisional histopathology (EH). There was no difference noted between FNA, NCB-14, or NCB-16 analyses. In addition, there was no difference in accuracy between FNA and NCB-14 or between FNA and NCB-14 versus NCB-16. Reported accuracy of FNA was 0.72, NCB-14 was 0.72, and NCB-16 was 0.64, respectively. Both FNA and NCB-14 displayed a sensitivity of 71% and NCB-16 a sensitivity of 53%. Both FNA and NCB-14 displayed a specificity of 75% and NCB-16 a specificity of 88%. The results demonstrated that NCB had no advantage clinically over FNA at diagnosing splenic pathology. This study further demonstrates that preoperative diagnostic evaluation of the spleen is not highly accurate and cannot be recommended prior to splenectomy.

Effect of needle gauge on pain and specimen quality of ultrasound-guided fine needle sampling without aspiration of the canine spleen

Modifications of splenic parenchyma are common ultrasonographic findings in dogs. Splenic fine needle aspiration (FNA) is a rapid, safe procedure, routinely performed in veterinary institutions. However, 22-gauge (G) needle usually reported is selected according to general practice and the most appropriate needle size to be used remains unclear. The aim of this prospective, single-center, methods comparison study was to assess the effect of needle size on cytologic specimens' evaluation and animal welfare during the procedure. Dogs underwent ultrasound-guided splenic FNA using 23, 25, and 27G needles. Needles were compared based on initial and then detailed cytologic evaluation. The initial evaluation assessed overall cellularity, cell preservation, hemodilution, and detailed cytologic evaluation referred to exhaustive splenic components. Welfare evaluation was performed based on a scoring system. A total of 54 dogs were included in this study with 54 of 54 welfare evaluations and 35 of 54 cytologic evaluations by one or two European College of Veterinary Clinical Pathology-certified cytologists. The final cytologic diagnosis was unchanged regardless of the needle size. For the initial evaluation, 23G needles provided significantly higher cellularity than the 27G needles. For detailed cytologic evaluation, only the richness in mesothelial cells and stroma was affected by needle size. Pain induced by the procedures was considered low using 23, 25, and 27G needles with the 27G needle producing the least adverse reactions. Findings from the current study supported using needle gauges smaller than the previously published standard 22G needle for spleen ultrasound-guided fine needle nonaspiration in dogs. Due to higher cellularity and lower pain scores, authors recommend the use of 23G needles with a nonaspiration technique.

A Comparative Investigation Applying Testicular Fine Needle Aspiration Cytology and Open Testicular Biopsy Histology for the Diagnosis of Azoospermia and Severe Oligospermia

Open testicular biopsy histology and fine needle aspiration cytology (FNAC) are the most popular tests used to diagnose male infertility. This study aimed to assess the cytological characteristics of 186 infertile males aged 24-63 with testicular FNAC. Furthermore, the existing relationship between males with severe oligospermia (sperm count: 5 million/ml) and azoospermia was investigated via both cytological and histological diagnosis methods. With a 1.5-inch and 25-gauge needle, the testis was aspirated from three locations (the upper, middle, and lower poles). Papanicolaou stain or Giemsa stain was used to make smears on albumenized slides, which were then dried in the air and stained. A biopsy of the testicles was performed there, preserved in Bouins solution, processed as usual, and stained with hematoxylin and eosin stain. According to our findings, 66.7% of patients had secondary maturation arrest, whereas 18.3% and 15.1% of them had hypospermatogenesis and Sertoli cell only (SCO). Results of the comparison showed that both procedures were very similar. According to biopsy histological examinations, only 3 (1.6%) of the 28 normal FNAC instances had hypospermatogenesis with lymphocyte infiltration. The majority of SCO patients were over 50 years old. These findings revealed that FNAC is more effective than testicular histology for the assessment of male infertility.

Implementation of a Fine Needle Aspirate Simulation Model

Being able to appropriately perform fine needle aspiration (FNA) collecting techniques and sample preparation is essential in obtaining a diagnostic sample, which is a critical skill for veterinary practitioners. Collection and preparation of cytologic samples are skills gained through practice. Experience leads to refinement of technique and improved diagnostic quality. Using live patients for mass skills training is not feasible; therefore, an aspiration simulation model and laboratory session was developed to reinforce physical exam skills, appropriate selection of sample collection supplies, and collection technique. Materials for the models include Ping-Pong balls, silicone, instant vanilla pudding mix, water, and stuffed animals. The laboratory session allows veterinary students to practice lesion identification, isolation, aspiration, and successful preparation. Subsequent submission of the collected sample involves being able to expel and spread the sample on a slide and proper labeling. While the simulation experience was initially developed for a short course with 12 students, it has recently been incorporated into the required clinical pathology clinical year rotation for up to 100 fourth-year veterinary students. The model is inexpensive and efficient and allows for technique development and immediate instructor assessment and feedback.

The Use of Simulators for Teaching Fine Needle Aspiration Cytology in Veterinary Medicine

Fine needle aspiration (FNA) is widely used by veterinary practitioners, being taught mostly by observation. Simulators are known to enhance students' learning of practice skills, but to our knowledge, FNA simulators have never been assessed in veterinary medicine. Fifty-one undergraduate students with no prior experience in cytology were randomly assigned to two groups that practiced on either a box simulator (with artificial nodules) or a fruit (banana). An in-class flip was followed, in which students first observed a FNA video tutorial and then used their assigned simulator for 15 minutes maximum. Students then attempted a FNA on an animal model and were evaluated through an objective structured clinical examination (OSCE). Learning outcomes of each model was compared through questionnaires, OSCE pass rates, and quality of produced smears. After observing the video, no student reported being able to conduct a FNA on a live animal, whereas most assured that they would be able to do so after using a simulator. Students practiced more on the box model (14.8 ± 0.8 min) than on the fruit (8.5 ± 2.2 min). At evaluation, students who had practiced on the box had more puncturing accuracy than those who had practiced on the fruit. Still, no differences in OSCE pass rates existed. Simulation models thus were effective for learning FNA, but the box simulator seemed to be more successful than the fruit in terms of deliberate practice. This appears to have a positive effect on students' puncturing accuracy, which has clinical relevance.

Caudal thigh intermuscular lipomas in dogs: Anatomic review and approach to surgical excision

The surgical approach for excision of caudal thigh intermuscular lipomas (IML) in dogs is described with relevant anatomy and short-term outcomes reported. Medical records were reviewed to identify dogs that underwent IML excision between 2015 to 2019. Signalment, location of the lipoma, pre-operative diagnostic tests, histopathology results, use of a closed-suction drain, and follow-up information including drain and suture removal were recorded. Mean age of patients in this study was 8.7 years. Multiple breeds were affected and there was no predilection for either left or right hind limb. Pre-operative diagnostic tests included fine-needle aspirate, radiography, peripheral ultrasonography, and/or computed tomography scan. In 45% (5/11) of the cases, a closed suction drain was placed. All masses removed were deemed grossly consistent with a lipoma by the attending clinician and 5 were confirmed by histopathology. No complications were noted in any case. Removal of caudal thigh IML requires careful identification of and dissection around the sciatic nerve, which is easily achieved with appropriate knowledge of the relevant anatomy and surgical approach.

Predictive ability of fine-needle aspirate cytology for incompletely resected mast cell tumor surgical sites

The goal of this study was to evaluate whether fine-needle aspirate cytology of a previous surgical site was predictive of recurrence for incompletely excised mast cell tumors (MCTs). Electronic medical records were searched for dogs diagnosed with MCTs; those with histologically confirmed, incompletely resected MCTs evaluated by scar aspiration cytology within 60 days after surgery were included for analysis. Variables were compared between groups using Fisher's exact test and logistic regression. Twenty-nine cutaneous and 7 subcutaneous tumors were evaluated. Local recurrence, confirmed by either histopathology or cytology, occurred in 13.8% of cases. No significant differences were identified for any variables other than surgical site cytology status. The negative predictive value of surgical site aspirate cytology without residual mast cell tumor was 93.5%, with an overall predictive accuracy of 88.9%. For the dogs evaluated in this report, surgical site aspiration cytology was predictive of local disease control for incompletely resected MCTs.

Identification of Mycobacterium genavense natural infection in a domestic ferret

A 6-y-old neutered male ferret ( Mustela putorius furo) was presented because of a 1-mo history of progressive weight loss, chronic cough, and hair loss. On clinical examination, the animal was coughing, slightly depressed, moderately hypothermic, and had bilateral epiphora. Thoracic radiography was suggestive of severe multinodular interstitial pneumonia. Abdominal ultrasound examination revealed hepatosplenomegaly and mesenteric and pancreaticoduodenal lymphadenopathy. Fine-needle aspiration of the pancreaticoduodenal lymph node, followed by routine Romanowsky and Ziehl-Neelsen stains, revealed numerous macrophages containing myriad acid-fast bacilli, leading to identification of mycobacteriosis. Autopsy and histologic examination confirmed the presence of disseminated, poorly defined, acid-fast, bacilli-rich granulomas in the pancreaticoduodenal and mesenteric lymph nodes, intestines, and lungs. Destaining of May-Grünwald/Giemsa-stained slides with alcohol, and then restaining with Ziehl-Neelsen, revealed acid-fast rods and avoided repeat tissue sampling without affecting the Ziehl-Neelsen stain quality and cytologic features. Tissue samples were submitted for a PCR assay targeting the heat shock protein gene ( hsp65) and revealed 100% homology with Mycobacterium genavense. We emphasize the use of special stains and PCR for identification of this potential zoonotic agent.

T-cell Thymic Lymphoma With Proventricular Metastasis in a Florida Scrub Jay ( Aphelocoma coerulescens)

An adult, wild-caught, female Florida scrub jay ( Aphelocoma coerulescens) was evaluated because of an observable mass on the ventral neck. Initial physical examination and diagnostic tests were performed, which revealed a subcutaneous mass. Surgical removal of the mass was attempted, but the bird died during surgery. Results of necropsy and histopathologic evaluation identified the mass as thymic lymphoma with proventricular metastasis. Immunohistochemical staining revealed strong cytoplasmic immunoreactivity for CD3 in the thymic mass and within the predominant lymphoid population in the serosal proventricular masses, which confirmed metastasis of T-cell lymphoma. To our knowledge, this is the first report of T-cell thymic lymphoma in a wild Florida scrub jay.

Evaluation of the diagnostic utility of cytologic examination of renal fine-needle aspirates from dogs and the use of ultrasonographic features to inform cytologic diagnosis

OBJECTIVE To describe cytologic characteristics of renal fine-needle aspirate (FNA) samples from dogs, evaluate proportions of cytologic specimens deemed adequate for interpretation (diagnostic yield), assess diagnostic utility of cytologic examination for neoplastic and nonneoplastic diseases, and characterize ultrasonographic features of evaluated kidneys to determine whether the imaging characteristics could be used to inform cytologic interpretations. DESIGN Retrospective, observational study. SAMPLE 102 cytologic specimens and 97 ultrasonographic studies from 100 dogs. PROCEDURES Medical records were reviewed to identify dogs that underwent ultrasound-guided renal FNA. Slides were categorized as adequate or inadequate for interpretation; adequate slides were used for retrospective cytologic diagnosis. Sensitivity, specificity, and predictive values of cytologic examination for detection of neoplastic and nonneoplastic conditions were calculated by comparison with histologic or lymphoid cell clonality assay results. Ultrasonographic characteristics of neoplastic and nonneoplastic renal lesions were described. RESULTS 74 of 102 (72%) specimens had slides adequate for interpretation; 26 were included in the diagnostic accuracy analysis. Sensitivity of cytologic examination was 78% and 50% for detection of neoplastic and nonneoplastic conditions, respectively, with specificities of 50% and 77%, respectively; sensitivity for detection of lymphoma was 100%. Ultrasonographic appearance of kidneys with confirmed neoplasia varied; masses were most commonly found in kidneys with carcinoma (5/5), lymphoma (5/7), or other neoplasia (3/4) and absent in kidneys with nonneoplastic conditions (n = 5). CONCLUSIONS AND CLINICAL RELEVANCE Renal FNA specimens were adequate for interpretation at rates comparable with those reported for other organs and were considered clinically useful for diagnosis of neoplasia. Imaging characteristics may potentially aid differentiation between neoplastic and nonneoplastic lesions; however, further investigation is needed.

Vertebral Polyostotic Lymphoma in a Young Dog

An unusual clinical presentation of lymphoma with vertebral involvement in a dog is reported. A 20-month-old intact female Golden Retriever presented with progressive paraparesis and anorexia. Complete blood count and serum biochemistry profile demonstrated pancytopenia and hypercalcemia. Ventral fusion of the lumbar vertebrae by new bony tissue deposition was evident on X-ray and CT scan. Fine needle aspiration revealed neoplastic lymphoid cells in lymph nodes and bone marrow. Histologically, vertebral bone and osteophytes, liver, bone marrow, kidney, and lymph nodes were diffusely infiltrated by neoplastic, lymphoid cells, with scant cytoplasm and round hyperchromatic nuclei. Polyostotic and medullary T-cell lymphoma with spondylosis was diagnosed. Lymphoma mainly affecting bone is uncommon in the dog. The present case differs from previously described polyostotic lymphomas in clinical signs of the disease, mainly attributable to spondylarthrosis. In addition, lymphomatous proliferation was associated with osteoproductive lesions of the vertebrae.

Exophthalmia Associated with Paranasal Sinus Osteoma in a Quarterhorse Mare

An 11-year-old Quarterhorse mare developed a paranasal sinus osteoma that extended into the right orbit and led to ipsilateral exophthalmia. Although the tumor was radiographically evident in the paranasal sinuses, ultrasonography was used to demonstrate extension of the tumor into the retrobulbar space, and endoscopy was used to identify its extension into the nasopharynx. Biopsies were obtained using both fine-needle aspiration and paranasal sinus trephination. Despite numerous antemortem diagnostic tests, only postmortem histologic analysis of the mass afforded the diagnosis of osteoma.

Fine-needle aspiration in the diagnosis of equine skin disease and the epidemiology of equine skin cytology submissions in a western Canadian diagnostic laboratory

Fine-needle aspiration (FNA) is commonly used to diagnose skin disease in companion animals, but its use in horses appears to be infrequent. Equine veterinarians in western Canada were surveyed to determine their opinions about FNA and 15 years of diagnostic submissions were used to compare the perceived to actual value of FNA in the diagnosis of skin disease in horses. Practitioners viewed FNA as quick, easy, economical, and minimally invasive. However, most veterinarians rarely chose to use FNA due to a perception that sample quality and diagnostic yield were poor and there was a narrow range of diseases the technique could diagnose. Analysis of the FNA cytology samples from a veterinary diagnostic laboratory showed a wide variety of equine skin disease conditions, but the frequency of non-diagnostic results was significantly higher in equine submissions compared to those from dogs and cats.

Evaluation of the ability of a gravitational filtration system to enhance recovery of equine bone marrow elements

OBJECTIVE

To assess efficiency of gravity filtration to enhance recovery of equine bone marrow elements including stem and progenitor cells.

ANIMALS

12 healthy adult horses.

PROCEDURES

Bone marrow aspirates were collected from the fifth sternebral body and filtered by gravitational flow to obtain bone marrow elements. Raw and harvested bone marrow and marrow effluent were evaluated for WBC and platelet counts, automated and cytomorphologic cell differential counts, mesenchymal stem cell CFUs, cell viability, and differentiation capacity. Isolated cells were analyzed for CD90 and major histocompatibility complex (MHC) class I and II antigens.

RESULTS

Mean cell viability of harvested bone marrow was 95.9%. Total WBCs and platelets were efficiently captured on the filter (> 95%), and mean recovery in harvested bone marrow was 30%. Cytologic cell differential counts indicated that the percentage of neutrophils was significantly less and the progenitor cell population was significantly higher and concentrated 1.56-fold in harvested bone marrow, compared with results for raw bone marrow. Flow cytometry and cell culture were used to characterize harvested bone marrow cells as positive for expression of CD90 and negative for MHCI and MHCII, which indicated stem cells with a multipotent phenotype that differentiated into chondrocytes, osteocytes, adipocytes, and tenocytes.

CONCLUSIONS AND CLINICAL RELEVANCE

Gravitational filtration of bone marrow efficiently yielded platelets and cells and produced a progenitor-enriched, leukocyte-reduced product, compared with raw bone marrow.

[Lethal alveolar echinococcosis in a dog: clinical symptoms and pathology]

Epidemiological data indicate a progressing spread of the fox tapeworm in Germany. Here we report on a case of lethal alveolar echinococcosis in a dog from Brandenburg. The patient was clinically presented with abdominal distension. Ultrasonic examination revealed severe structural alterations of the liver and in a fine needle aspiration cytology larval tape worm fragments were suspected. Explorative laparotomy suggested inoperable lesions and the animal was euthanized with unfavorable prognosis. Pathology confirmed the diagnosis of hepatic echinococcosis. PCR analysis of the liver identified Echinococcus multilocularis, the so called "small fox tapeworm". The infection, reportable in Germany, is an important zoonotic disease that is transmitted by accidentally ingested tapeworm eggs shed by foxes or dogs. The prevalence between 7.6% and 16.7% in the fox population of Brandenburg is significantly lower than in the endemic regions of South and Southwest Germany, however, it is suspected to increase. This underlines the importance of a regional monitoring in domestic animals living in close contact to humans. In this regard, especially dogs should be taken into consideration as a potential definitive host and source of infection for people.

Needle tract implantation after fine needle aspiration biopsy (FNAB) of transitional cell carcinoma of the urinary bladder and adenocarcinoma of the lung

This paper reports three clinical cases of needle tract implantation of neoplastic cells on the abdominal and thoracic wall after ultrasound (US) fine needle aspiration biopsy (FNAB). Primary tumors were two transitional cell carcinomas of the urinary bladder (2 dogs) and one pulmonary adenocarcinoma (1 cat). All three masses grew up along the needle tract. To our knowledge, the seeding of pulmonary adenocarcinoma cells after FNAB on the thoracic wall has never been reported in veterinary medicine.

Blood parameters in female Zandi lambs as affected by liver biopsy methodology

The aim of the present study was to investigate the normal blood parameters of Iranian fat-tailed sheep (Zandi) and their changes due to rapid liver biopsy technique with a tru-cut biopsy needle. In ten ewe lambs, blood samples were collected from jugular vein and biopsy needle was inserted through the dorsal one third of the 11th intercostal space, on the right hand side of the lambs and liver specimen was collected. Physical examinations were performed on alternate days during the experiment. Blood collection was done on both before (day 1) and after (day 17) the biopsy. All animals were slaughtered at day 17. Values were compared using paired t test. While biopsy did not make any significant changes in mean values of body temperature, heart rate, respiratory rate, PCV, WBC, neutrophil, lymphocyte, eosinophil, monocyte, total serum protein, AST, ALT, and serum calcium (p > 0.05), it made a significant difference on the values of ALP (p < 0.001), serum inorganic phosphate (p = 0.035), and magnesium (p = 0.013). Necropsy examination revealed the points of hitting the biopsy needles on the diaphragmatic surface of the livers, surrounded by a zone of intense hyperemia. Peritoneal adhesions accompanying with typical strands of fibrous connective tissue between diaphragmatic surface of the liver and adjacent abdominal wall were found in two cases.

Central nervous system blastomycosis in a dog

An adult golden retriever was presented for progressive neurologic dysfunction. Clinical examination suggested brainstem disease. Blastomycosis was diagnosed based on fine-needle aspiration cytology of a normal sized lymph node and a positive blastomycosis urine antigen test. Systemic blastomycosis with neurologic involvement was confirmed at necropsy.

Panniculitis, polyarthritis and osteomyelitis associated with pancreatic neoplasia in two dogs

A 12-year-old crossbred dog (case 1) and a 12-year-old Shetland sheepdog (case 2) were presented with a history of lameness and distal limb swelling. Physical examination revealed joint effusions and asymmetrical swellings of the extremities. In case 1, a diagnosis of arthritis and cellulitis was made on fine-needle aspiration biopsy of the synovium and subcutis. In case 2, bone biopsies and synovial aspirates diagnosed osteomyelitis and arthritis. A diagnosis of pancreatic disease was made on the findings of marked elevations of serum lipase concentrations and ultrasonographic identification of pancreatic masses in both cases. Both the cases were non-responsive to symptomatic management and were subsequently euthanased. Postmortem examination confirmed the diagnosis of panniculitis, arthritis and osteomyelitis in both cases. A pancreatic exocrine adenoma was identified in case 1 and a pancreatic adenocarcinoma with widespread metastases in case 2. To the authors' knowledge the association of panniculitis, polyarthritis and osteomyelitis with pancreatic disorders has not been reported previously in canine clinical cases.

Squash-preparation cytology from nasopharyngeal masses in the cat: cytological results and histological correlations in 30 cases

Upper airway obstruction in cats can be a life-threatening condition. Early recognition of clinical signs and an appropriate diagnostic approach increases the possibility of appropriate therapeutic choices. The purpose of this study was to assess the efficacy and diagnostic value of squash-preparation cytology in providing an accurate diagnosis of masses growing in the nasopharynx of cats. Cytological specimens prepared by a squash technique from nasopharyngeal masses in 30 cats were collected under direct endoscopic guidance and classified into four groups: benign inflammatory/hyperplastic mass, lymphoma, carcinoma and sarcoma. The cytopathological diagnosis was compared with the final histopathological diagnosis and indices of diagnostic test accuracy were calculated. The results showed good agreement between the cytological and histological diagnosis with a sensitivity of 0.94, a specificity of 0.81, a positive likelihood ratio of 0.9, a negative likelihood ratio of 0.9 and an overall accuracy of 0.9. Squash-preparation cytology is considered an accurate diagnostic tool for distinguishing benign from malignant nasopharyngeal masses in cats. For differentiation of lymphoma and lymphoid reactions histopathological confirmation is recommended.

Diagnosis and successful treatment of a caudal lingual abscess in a geriatric dog

A 13-year-old, intact male, golden retriever was presented for glossomegaly. A diagnosis of a caudal lingual abscess was made by fine needle aspiration under general anesthesia. The dog showed marked clinical improvement following abscess drainage. Lingual abscesses should be included as a differential diagnosis in any dog with an unexplained acute glossomegaly.

Evaluation of accuracy of fine needle aspiration cytology for diagnosis of canine mammary tumours: comparative features with human tumours

OBJECTIVE

The authors evaluated the accuracy of the fine needle aspiration cytology technique in the diagnosis of 77 canine mammary gland tumours using the same cytological and histological criteria currently applied to the diagnosis of human breast cancer.

METHODS

The study was performed in 73 pure or mixed-breed female dogs submitted to surgical resections of 'mammary tumours'. All cytological smears were stained by routine May-Grunwald-Giemsa and Papanicolaou stains.

RESULTS

We obtained a correct cyto-histological correlation in 52/77 cases (67.5%) when all cytopathological examinations were considered, and in 52/56 cases (92.9%) when the inconclusive cases were excluded from the analysis.

CONCLUSION

Our results demonstrate that, because of the similarity of the cytological findings in the human and canine mammary gland tumours, it is possible to use the same cytological criteria applied in human pathology for the diagnosis of canine mammary gland tumours.

Advances in the diagnosis and management of cutaneous mast cell tumours in dogs

Mast cell tumours are one of the most common tumours of the canine skin and have a reputation for being difficult to manage because of their variable clinical presentation, behaviour and response to treatment. This review of recent literature on canine mast cell tumours suggests that the majority of such tumours may not be as bad as their reputation suggests. Most grade I and grade II tumours can be managed successfully by good surgery. Recent literature also calls into question the utility of clinical staging systems and the value of assessing surgical margins for prognosis and highlights the paucity of well-conducted, case-controlled clinical trials in assessing the efficacy of medical management of high-risk tumours. In terms of more basic research, recent studies have implicated the stem cell factor receptor KIT as having a role in the aetiology of canine mast cell tumours and there appears to be an association between c-kit mutation and higher grade of tumour. This may offer a possible target for new therapeutic approaches.

Mucinous Cholangiocarcinoma in a Cat

Mucinous cholangiocarcinoma was diagnosed in a 14-year-old, castrated male, domestic shorthaired cat with marked peritoneal effusion. Cytological confirmation of malignancy by fluid analysis and fine-needle, ultrasound-guided aspiration of the liver was followed by histological examination of tissue samples obtained at surgery and necropsy. No observed response followed chemotherapy with doxorubicin and carboplatin. Electron microscopy and immunohistochemistry helped to further characterize this unusual tumor.

Correlation of ultrasonographic appearance of lesions and cytologic and histologic diagnoses in splenic aspirates from dogs and cats: 32 cases (2002–2005)

OBJECTIVE

To determine the accuracy of cytologic diagnosis, compared with histologic diagnosis, in determination of disease in ultrasound-guided fine-needle aspirates of splenic lesions.

DESIGN

Retrospective study.

SAMPLE POPULATION

Splenic specimens from 29 dogs and 3 cats.

PROCEDURES

Records were searched for dogs and cats that had undergone ultrasound-guided splenic aspiration. Criteria for inclusion were ultrasonographic identification of splenic lesions and cytologic and histologic evaluation of tissue from the same lesion. Cytologic samples were obtained by fine-needle aspiration, and histologic specimens were obtained via surgical biopsy, ultrasound-guided biopsy, or necropsy.

RESULTS

Cytologic diagnoses corresponded with histologic diagnoses in 19 of 31 (61.3%) cases and differed in 5 of 31(16.1%) cases, and 1 aspirate was inadequate for evaluation. In 7 of 31 (22.6%) cases, histologic evaluation of tissue architecture was required to distinguish between reactive and neoplastic conditions. On the basis of histologic diagnosis in 14 animals with nonneoplastic conditions, the cytologic diagnosis was correct in 11 cases, not definitive in 2 cases, and incorrect in 1 case. In 17 animals with malignant neoplastic diseases, the cytologic diagnosis was correct in 8 cases, not definitive but consistent with possible neoplasia in 5 cases, and incorrect in 4 cases. Multiple similar-appearing nodules were significantly associated with malignancy, whereas single lesions were more often benign.

CONCLUSIONS AND CLINICAL RELEVANCE

Ultrasound-guided aspiration of splenic lesions is a minimally invasive tool for obtaining specimens for cytologic evaluation. Although cytologic diagnoses often reflect histologic results, if missampling or incomplete sampling occurs or tissue architecture is required to distinguish between reactive and neoplastic conditions, accurate diagnosis with fine-needle aspiration may not be possible.

Diagnosing appendicular osteosarcoma with ultrasound-guided fine-needle aspiration: 36 cases

OBJECTIVES

To determine the ability to obtain diagnostic cytology samples from appendicular bone lesions using ultrasound-guided needle aspirations. Secondary objectives were to compare cytological evaluations with histopathological results and to determine the utility of staining malignant mesenchymal cells for the presence of alkaline phosphatase.

METHODS

Aspirations from 36 aggressive appendicular bone lesions with histological diagnoses were included in the study. Ultrasound was used to guide the needle to the medullary cavity or the adjacent soft tissue mass. The smears stained with Wright-Giemsa and nitroblue tetrazolium chloride/5-bromo-4-chloro-3-indoyl phosphate toluidine salt (NBT/BCIP) were examined.

RESULTS

A diagnostic sample was obtained in 32 of the 36 cases. Of the 32 diagnostic samples, cytology indicated sarcoma, with a sensitivity of 97 per cent (confidence interval: 83 to 100 per cent) and a specificity of 100 per cent (confidence interval: 16 to 100 per cent). When a diagnosis of sarcoma was made on cytology, alkaline phosphatase staining indicated osteosarcoma, with a sensitivity of 100 per cent (confidence interval: 87 to 100 per cent).

CLINICAL SIGNIFICANCE

The results of this study indicate that ultrasound-guided needle aspiration of aggressive bone lesions is a viable technique for identifying malignant mesenchymal cells and for diagnosing sarcomas. It is cost-effective and minimally invasive. Furthermore, identifying alkaline-phosphatase-negative malignant mesenchymal cells from a bone aspiration may rule out osteosarcoma, whereas alkaline-phosphatase-positive malignant mesenchymal cells are suggestive of osteosarcoma.

Comparison of core needle biopsy and fine-needle aspiration of enlarged peripheral lymph nodes for antemortem diagnosis of enzootic bovine lymphosarcoma in cattle

OBJECTIVE

To determine whether antemortem core needle biopsy and fine-needle aspiration of enlarged peripheral lymph nodes could be used to distinguish between inflammation and lymphosarcoma in cattle.

DESIGN

Prospective study.

ANIMALS

25 cattle with enlarged peripheral lymph nodes.

PROCEDURES

Antemortem biopsies of the selected lymph nodes were performed with an 18-gauge, 12-cm core needle biopsy instrument. Fine-needle aspirates were performed with a 20-gauge, 4-cm needle. Specimens were analyzed by pathologists who were unaware of clinical findings and final necropsy findings, and specimens were categorized as reactive, neoplastic, or nondiagnostic for comparison with necropsy results.

RESULTS

Sensitivity and specificity of core needle biopsy ranged from 38% to 67% and from 80% to 25%, respectively. Sensitivity of fine-needle aspiration ranged from 41% to 53%, and specificity was 100%. Predictive values for positive test results ranged from 77% to 89% for core needle biopsy and were 100% for fine-needle aspiration. Predictive values for negative test results were low for both core needle biopsy and fine-needle aspiration.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that core needle biopsy and fine-needle aspiration can aid in the antemortem diagnosis of bovine enzootic lymphosarcoma. Results of fine-needle aspiration of enlarged peripheral lymph nodes were more specific and more predictive for a positive test result than were results of core needle biopsy.