Fine Needle Aspiration Cytology in the Diagnosis of Canine Thyroid Carcinoma

In 11 dogs with thyroid carcinomas there was a good correlation between cytological results of fine needle aspiration biopsy and histological findings. The only difficulty with the aspiration technique was excessive contamination with blood of a third of the specimens.     

Fine needle aspiration cytology and histologic correlation in canine tumors

Fine needle aspiration biopsy was performed on 147 skin tumors in 119 dogs over a 4-year period. Both air-dried smears (Wright's stain) and wet-fixed smears (Papanicolaou's stain) were prepared from the aspirates from each tumor and the cytological diagnosis was correlated with histology. In 105 tumors, the cytological and histological interpretations agreed. Histologically, there were 36 stromal tumors, including 19 fibrosarcomas and nine hemangiosarcomas. Cytologically, 12 of the fibrosarcomas and five of the hemangiosarcomas were interpreted correctly as malignant tumors. All 11 melanomas and all 37 mast cell tumors were identified correctly cytologically, while nine of the 11 squamous cell carcinomas, 15 of 21 adenocarcinomas and eight of 19 mammary carcinomas were interpreted as malignant using aspiration biopsy. The fine-needle technique also identified 16 dogs with metastases to the regional lymph nodes before surgical biopsies were undertaken. Benign tumors were incorrectly described as malignancies in only three cases.     

Cytological diagnosis of mandibular salivary gland adenocarcinoma in a dog

A case of mandibular salivary gland adenocarcinoma in a 9-year-old female dog is described. Material collected by fine needle aspiration underwent cytological examination and after the diagnosis of salivary carcinoma the mass was surgically excised and then was processed for histological examination. The aim of this work is to describe the cytopathological features of this carcinoma and to emphasize the usefulness of fine needle aspiration technique, which is an effective, inexpensive and minimally invasive method of diagnosis that can be performed before incisional biopsy or even before surgical excision.     

The cytopathological features of thymoma in a dog

A dog presenting with weight loss and displacement of the heart to the right was diagnosed as having a thymoma by transthoracic fine-needle aspiration biopsy. The cytological findings are described and correlated with the histological findings. Cytologically the lesion contained numerous large clusters of neoplastic epithelial cells with scant basophilic cytoplasm, and scattered, well-differentiated lymphocytes. Histologically the thymoma was composed of predominantly spindle-shaped epithelial cells arranged in broad sheets or forming sworling and storiform patterns. Some lobules contained lymphoid cells.     

Cytology and the cell block method in diagnostic characterization of canine lymphadenopathy and in the immunophenotyping of nodal lymphoma

Minimally invasive techniques used to evaluate canine peripheral lymphadenopathy (PLN), including fine needle aspiration biopsy with cytological evaluation (FNAB‐C) and flow cytometry (FC), have benefits and limitations. The cell block (CB) method is an alternate processing technique in which fine needle aspirate biopsy samples are concentrated, fixed, and embedded in paraffin for routine histological processing/staining. Utilizing three observers, we determined the diagnostic value of the CB in evaluating canine PLN across six categories (non‐diagnostic, reactive, inflammatory/infectious, probable lymphoma and lymphoma, metastatic neoplasia) and correlated findings to immunophenotypic and clonal antigen receptor rearrangement results in canine nodal lymphoma. Eighty‐five paired FNAB‐C and CB samples were evaluated from canine patients presenting to the University of Minnesota Veterinary Oncology or Internal Medicine services. Diagnostic quality samples were obtained in 55/85 (65%) CB and 81/85 (95%) FNAB‐C samples, respectively, and nodal pathology impacted CB diagnostic yield. Overall percent agreement between diagnostic‐quality FNAB‐C and CB samples was 86%, but increased to 95% if the categories of lymphoma and probable lymphoma were combined. There was 100% agreement for both the diagnoses of metastatic neoplasia and reactive lymph nodes and 92% agreement for the diagnosis of lymphoma/probable lymphoma. Using immunohistochemistry (IHC), CB samples correctly immunophenotyped 22/23 (96%) cases of B‐cell lymphoma, but only 1/6 (17%) cases of T‐cell lymphoma. IHC was not completed on nine cases of lymphoproliferative disease because of insufficient cellularity. When the CB method (CBM) yielded diagnostic quality samples there was good to excellent agreement with FNAB‐C samples and CB samples were suitable for some IHC tests.     

犬毛母质瘤的细胞学特征

犬毛母质瘤是皮肤基底细胞发生的良性肿瘤,在临床上非常罕见,占皮肤活检病例的1%,其细胞学特征主要为基底细胞和影细胞。人医在毛母质瘤细针穿刺细胞学检查在临床上有较高的诊断率,但笔者收治的一例犬毛母质瘤,有大量黑素颗粒和淋巴细胞,容易和黑色素瘤、转移性淋巴瘤混淆,从细胞学检查很难确定为毛母质瘤,组织病理学检查确定为毛母质瘤。     

Fine needle aspiration biopsy of malignant tumors in dogs and cats: a report of 102 cases

Fine needle aspiration biopsy is a fast and inexpensive technique well tolerated by animals. Its efficacy for the diagnosis of malignancy and determination of cellular origin was investigated for 97 malignant tumors and five benign lesions in 83 dogs and 19 cats. Histological examination of the lesions was performed in each case. Malignancy was detected by cytology in 69% of the malignant tumors. The cellular origin of the lesion was determined in 74% of the cases. Confirmation of malignancy and determination of cellular origin permitted an early diagnosis and prognosis. Since fine needle aspiration biopsy and cytology cannot definitely rule out malignancy, a surgical biopsy and histopathology should be done when malignancy is suspected clinically and not confirmed cytologically. Specimens of good quality, adequate collaboration between the cytologist and clinicians, and sufficient knowledge of pathology and cytology are basic requirements for obtaining good results with fine needle aspiration biopsy and cytology.     

Testicular fine needle aspiration cytology as a diagnostic tool in dog infertility

The results of testicular aspirate cytology taken from clinical patients with a history of infertility were compared with the clinical and histological findings. Azoospermia was the most common and the most rewarding indication for the examination. Samples were also taken from cases with suspected testicular tumours, orchitis, epididymitis, severe oligo- and teratozoospermia, lack of libido and unilateral testicular atrophy. Histological and cytological findings were found to correlate well. Identification of cell types from normal germinal epithelium was relatively easy. No Immediate adverse effects of aspiration were noted. Five normospermic dogs were monitored for two to six months after aspiration, and there were no marked deleterious effects on testicular consistency, testicular histology or semen characteristics. Testicular cytology obtained by fine needle aspiration may, at least to some extent, be used to assist clinical diagnosis, especially In azoospermlc dogs and dogs with palpable changes of testicular tissue.     

Cytopathology of canine lymphomas (100 cases)

Malignant lymphoma is one of the most common malignant tumours occurring in dogs. Fine needle aspiration biopsy (FNAB) is an excellent, specific diagnostic procedure used to assess pathological processes in lymph nodes. The aim of the present study was to conduct a cytopathological analysis of lymphoma in dogs and to analyse some epidemic aspects of occurrence of lymphoma in 100 dogs using Giemsa stained slides. Samples were obtained by fine needle aspiration biopsy, fine needle non-aspiration biopsy, lymph node impression smears and by examination of body cavity effusions. The determination of the type and subtype of tumour was made on the basis of the updated Kiel classification adopted for dogs. Based on cytopathological analysis, the lymphoma was diagnosed in 100 dogs: 44 were female and 56 male. The animals' age ranged from 1.5 year to 15 years (median: 7.5 years), the animals were of different breeds (72% of all dogs belonged to 28 different breeds) and crossbreeds (28%). In 29% of dogs the regional or general lymphadenomegaly was the only clinical sign observed, in remaining cases (71%) at least one abnormality connected to lymphoma was found. Among all diagnosed lymphomas, high-grade lymphomas were more prevalent (86% of all cases) than low-grade lymphomas (14% of all cases). The possibility of boxers having a predisposition to T cell lymphoma development could be also suspected.     

Benign cranial mediastinal lesions in three cats

Cranial mediastinal lesions were detected in three cats, associated with respiratory impairment (case one), spontaneous pneumothorax (case two) and myasthenia gravis (case three), respectively. On gross and histological examination, the first case was considered either a lymphangioma or a branchial cystic mass of the thymic region of the mediastinum; a cystic lesion was suggested by sonographic detection of multiple anechoic cavitations within a circumscribed mass, while fine needle aspiration cytology excluded lymphosarcoma. The second case was diagnosed histologically as a cystic thymoma, but the third case was not examined microscopically. The masses were amenable to surgical excision in the first two cats, while this proved unnecessary in the third case because of resolution following treatment with dexamethasone. Corticosteroid responsiveness was unhelpful in distinguishing between these benign lesions and lymphosarcoma, as in two cases there was a partial or complete response to dosing with prednisolone or dexamethasone. These cases are presented to emphasise that conditions other than lymphosarcoma can produce cranial mediastinal lesions in cats, and that the prognosis for surgical treatment of lymphangiomas, multilocular thymic cysts and cystic thymomas can be excellent.     

Transitional cell carcinoma of the renal pelvis in two dogs

Transitional cell carcinoma (TCC) of the renal pelvis was found in two dogs, a 7-year-old male English Setter and a 11-year-old female Shetland shepherd. Affected dogs were presented for clinical examination without any specific symptoms but haematuria in case 1 and occurrence of whitish material in the urine of case 2; neoplastic disorders were discovered with ultrasonographic investigation and fine needle aspiration biopsy. Histopathological examination was carried out after nephrectomy and ureterectomy of the affected kidney of both dogs, and confirmed the diagnosis of non-invasive and low grade TCC in case 1 and of infiltrating TCC in case 2. The clinical, gross, cytological and histopathological features of these rare tumours originating from transitional epithelium of the renal pelvis are reported.     

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.     

Development of a teaching laboratory aid for instruction of fine needle aspiration biopsy cytology technique

Specialized training is required to obtain adequate cytology smears by needle aspiration biopsy. An educational method that would provide opportunity for numerous trainees to acquire needle aspiration biopsy and cytodiagnostic skills, and which would not result in the interruption of teaching hospital patient care nor result in the use or sacrifice of animals from laboratory animal resources was sought. An aspiration biopsy cytology teaching aid was developed by placing portions of fresh organ tissue from routine submissions to the necropsy laboratory into a specimen container partially filled with chilled normal saline solution. Specimens were stored immersed in saline at 4 degrees C for up to 48 hours. Prior to the cytopathology teaching laboratory period, the specimen container was removed from storage and covered with a latex diaphragm. Instructors responsible for teaching cytodiagnostic techniques used this ex vivo aspiration biopsy cytology device for instruction of fine needle aspiration biopsy, specimen processing, and microscopy. In the teaching laboratory, puncture of the diaphragm and aspiration of a tissue sample with hypodermic needle and syringe was instructed to, and practiced by, numerous trainees simultaneously using clinical operative technique without the need for live animals. Trainees prepared and stained cytology smears as well as evaluated and interpreted specimens in a single, realistic exercise. Such training experience may improve ability of trainees to procure diagnostic-quality biopsy specimens for cytodiagnosis of lesions from clinic patients.     

Cytological grading of canine cutaneous mast cell tumours

A cytological grading for mast cell tumours (MCTs) would be highly desirable, allowing to select the most appropriate therapeutic intervention prior to surgery. This study evaluates the applicability on fine‐needle aspirations (FNAs) of the novel Kiupel grading system, based on number of mitoses, multinucleated cells, bizarre nuclei and presence of karyomegaly. Fifty consecutive cases with pre‐operative cytological diagnosis were included. In cytological specimens, approximately 1000 cells were evaluated, and the histological grade was assessed on the corresponding resected specimens. On cytology, the above parameters were significantly different between histologically low‐grade and high‐grade tumours (P < 0.001). The cytograding correctly predicted the histological grade in 47 cases (accuracy, 94%; sensitivity, 84.6%; specificity, 97.3%). Two high‐grade MCTs (4%) were not detected on cytology. The cytograding can provide helpful insights to assist clinical decisions in most cases. However, the risk of underestimation in a minority of patients represents a limit to the overall utility of the technique.     

Ultrasound-guided fine needle aspiration in the diagnosis of peripheral nerve sheath tumors in 4 dogs

Ultrasound-guided fine needle aspiration was used in establishing the diagnosis in 4 cases of malignant peripheral nerve sheath tumor. Sonographic and cytologic characteristics are discussed. Because of its availability and ease of use, axillary ultrasonography with fine needle aspiration can be an initial diagnostic step for suspected brachial plexus tumors.     

Clinical safety of percutaneous ultrasound‐guided fine‐needle aspiration of adrenal gland lesions in 19 dogs

Objective

To evaluate the safety of fine‐needle aspiration of adrenal gland lesions in dogs and to characterise the risks in a subset of patients with cytologically or histopathologically diagnosed phaeochromocytoma.

Materials and Methods

Retrospective review of medical records of dogs that underwent percutaneous ultrasound‐guided fine‐needle aspiration of adrenal gland lesions between August 2014 and December 2016. Nineteen dogs were identified, with three undergoing bilateral adrenal gland aspiration and one dog undergoing aspiration twice, yielding 23 cytology samples in total. Data collected included signalment, concurrent medical conditions, current medications, blood pressure and heart rate before adrenal fine‐needle aspiration, imaging characteristics of the adrenal gland lesions and any clinically apparent procedure‐related complications.

Results

Phaeochromocytoma was diagnosed in nine of 19 dogs, including one dog with bilateral phaeochromocytoma. One dog developed ventricular tachycardia following aspiration of an adrenal gland lesion cytologically consistent with a phaeochromocytoma.

Clinical Significance

Percutaneous ultrasound‐guided fine‐needle aspiration of adrenal gland lesions appears to be relatively safe, even in phaeochromocytoma, but further data are required to lend more weight to this finding. Minimally invasive aspirates could be considered as part of the diagnostic algorithm in the investigation of an incidentally detected adrenal gland lesion of uncertain clinical significance.     

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.     

Psychomotor epilepsy associated with metastatic thymoma in a dog

A seven-year-old female German shepherd dog was presented with a history of anorexia, weight loss and fever of three months' duration. On general examination she showed a marked behavioural change represented by episodic excitement and 'fly snapping. A general blood screening showed neutrophilia with left shift and hyperalbuminaemia. Survey radiographs were taken and a mass was identified in the cranial mediastinum. Cytological examination of fine needle aspiration smears of the mass yielded a presumptive diagnosis of lymphoma. The dog was euthanased and necropsy findings concluded that the primary tumour was a thymoma; metastases were found in the choroid plexus, leptomeninges, cerebral cortex and hippocampus.     

Fine-needle aspirate cytology suggesting hepatic lipidosis in four cats with infiltrative hepatic disease

Four cats are reported in which cytology smears obtained by ultrasound-guided fine needle aspiration of the liver were interpreted as indicative of hepatic lipidosis. However, histopathology of hepatic tissue samples obtained with Tru-Cut-like needles or wedge biopsy revealed that the cats had inflammatory or neoplastic hepatic disease causing their clinical signs. Fine needle aspiration and cytology may not detect infiltrative lesions, particularly those that are nodular, multifocal, or localised around the portal regions. Fine needle aspirate cytology is a useful diagnostic procedure with many advantages, but care must be taken to avoid diagnosing hepatic lipidosis as the cause of illness when an infiltrative lesion is responsible.