A novel method of core aspirate cytology compared to fine-needle aspiration for diagnosing canine osteosarcoma

There is little information in veterinary literature regarding the diagnostic accuracy of aspirate cytology for the diagnosis of canine osteosarcoma (OSA). The authors compared the diagnostic accuracy of a novel method of cytologic collection, termed core aspirate cytology (CA), with fine needle aspiration (FNA) and histopathology in 27 dogs with lytic and/or proliferative bone lesions. Alkaline phosphatase (ALP) staining was performed to confirm the diagnosis of OSA cytologically. OSA was accurately diagnosed in 85% and 95% of FNA and CA, respectively. ALP staining was 100% sensitive for the diagnosis of OSA. CA using a bone marrow biopsy needle allowed for penetration of cortical bone and aspirate cytology with a larger bore needle than FNA; however, there was no significant difference in diagnostic accuracy between techniques. Aspirate cytology with ALP staining was a safe, accurate, and minimally invasive diagnostic test for the evaluation of suspected OSA lesions in dogs.     

ULTRASOUND-GUIDED FINE-NEEDLE ASPIRATION BIOPSY OF BONE LESIONS: A PRELIMINARY REPORT

The purpose of this preliminary study was to determine the feasibility of ultrasound-guided fine-needle aspiration biopsy of suspected neoplastic lesions of bone. Ultrasound-guided fine-needle aspiration biopsy samples were obtained in 23 patients (22 dogs and one cat) with radiographic evidence of a destructive or destructive/productive bone lesion. The lesions were located in the appendicular skeleton in 20 patients and in the axial skeleton in three. Histopathology from tissue core biopsies and/or necropsy was not deemed necessary in 11 patients where ultrasound-guided fine-needle aspiration biopsy results were conclusive for neoplasia. A cytologic diagnosis from ultrasound-guided fine-needle aspiration biopsy was confirmed by histologic samples obtained at surgery or necropsy in five patients. In one of these five, ultrasound-guided fine-needle aspiration biopsy samples were diagnostic for sarcoma when tissue-core biopsy was inconclusive. Both ultrasound-guided fine-needle aspiration biopsy and tissue core biopsy techniques were inconclusive in one patient. Ultrasound-guided fine-needle aspiration biopsy samples were nondiagnostic in five patients where a follow-up histopathologic diagnosis of neoplasia was made. It was concluded that ultrasound-guided fine-needle aspiration biopsy of bone, if diagnostic, may help avoid the need for a tissue-core biopsy in some instances. However, a negative ultrasound-guided fine-needle aspiration biopsy sample does not rule out neoplasia. A negative ultrasound-guided fine-needle aspiration biopsy should be followed by a tissue-core biopsy and histologic analysis in all patients. Ultrasound-guided fine-needle aspiration biopsy seems to be a promising technique for the diagnosis of bone lesions.     

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.     

Bone allografts and adjuvant cisplatin for the treatment of canine appendicular osteosarcoma in 18 dogs

The results achieved in 18 dogs following the use of frozen bone cortical allografts for limb-sparing resection of non-metastatic canine appendicular osteosarcoma are presented. Three to five cisplatin doses (70 mg/m2) were administered, starting the day after surgery. The mean and median survival times were 478 and 266 days (range 80 to 2,611 days), respectively. The survival rate was 94 per cent at three months, 78 per cent at six months, 35 per cent at 12 months, 23 per cent at 18 months and 19 per cent at 24 months; the disease-free interval was 80 to 1,246 days (mean 365 days, median 266 days). Lung metastasis developed in 55 per cent of the dogs within one year. Complications were observed in 14/18 dogs (78 per cent), comprising local recurrence (28 per cent), allograft infection (39 per cent) and implant failure (11 per cent). Despite complications, limb sparing is a useful alternative to amputation in selected cases of appendicular osteosarcoma.     

OSTEOSARCOMA OF THE PATELLA WITH PULMONARY METASTASES IN A DOG

A 6-year-old neutered male Rottweiler was examined for a progressive right pelvic limb lameness. In radiographs of the right stifle, there was an osteolytic lesion with irregular new bone formation along the cranial aspect of the patella consistent with an aggressive bone lesion. In thoracic radiographs, there were multiple soft tissue nodular opacities throughout the lung fields, consistent with pulmonary metastases. Microscopically, fine needle aspirate samples from the right patella contained pleomorphic spindle cells with cytologic features of osteosarcoma. The presence of pulmonary metastases at the time of initial diagnosis in the dog described herein suggests that osteosarcoma of the patella has the potential for similar aggressive biologic behavior as that seen in dogs with appendicular osteosarcoma.     

BONE SCINTIGRAPHY FOR METASTASIS DETECTION IN CANINE OSTEOSARCOMA

The purpose of this study was to assess the usefulness of serial bone scintigraphy in the detection of skeletal and extraskeletal metastases in dogs with appendicular osteosarcoma. Twenty-six dogs with primary, appendicular osteosarcoma were entered into a limb-sparing protocol. Bone scintigraphy was performed upon presentation, after neoadjuvant therapy but prior to surgery and at selective intervals after limb-sparing surgery to evaluate for the presence of metastasis. Thoracic radiographs, and radiographs of other sites, were also made at the time of each bone scan. All dogs had a complete necropsy. No dog had bone or lung metastases detected prior to treatment. The bone scans, medical records, and radiographs of each dog were reviewed retrospectively. All but one dog developed metastatic disease. Bone metastatic sites were confirmed at necropsy in 12 of the 26 dogs. Seven of these 12 dogs had bone metastatic sites which were not producing clinical signs, i.e. an occult metastasis. In five of the seven dogs, the occult site was the first metastatic site detected. Extraskeletal metastases were identified scintigraphically in six of the 26 dogs, but these were clinically apparent prior to bone scintigraphy in each dog. Suspected malignant scintigraphic lesions were proven benign in six dogs. In five dogs with malignant bone lesions at necropsy the last bone scan prior to euthanasia was normal. The time interval between scintigraphy and necropsy was variable in these five dogs. All dogs without bone metastases at necropsy had normal bone scans. This study validates the usefulness of bone scintigraphy for detection of occult bone metastasis and improved ability for tumor staging in dogs with appendicular osteosarcoma.     

Neoplastic pleural effusion and intrathoracic metastasis of a scapular osteosarcoma in a dog: a multidisciplinary integrated diagnostic approach

A 10‐year‐old, female spayed mixed‐breed or cross‐bred dog was referred to the Small Animal Teaching Hospital of the University of Liverpool due to tachypnea, dyspnea, and pleural effusion not responding to diuretics and antibiotics. The chest was drained and cytology of the pleural fluid was consistent with a modified transudate with presence of atypical cells initially attributed to mesothelial hyperplasia and dysplasia. Computed tomography detected, in addition to the bilateral pleural effusion, diffuse pleural thickening, multiple pleural and pulmonary nodules, and a mineralized and lytic mass in the left scapula. Imaging findings were suggestive of a primary bone tumor with intrathoracic metastasis. Cytology of the left scapular and pleural masses revealed a malignant neoplasm highly suggestive of osteosarcoma. The diagnosis was confirmed by demonstration of a positive cytochemical reaction for alkaline phosphatase on prestained cytology slides. This finding prompted review of the initial interpretation of the pleural effusion cytology. The presence of neoplastic osteoblasts in the thoracic fluid was identified by a combination of cytochemistry, cell pellet immunohistochemistry, and transmission electron microscopy findings. In this report, a multidisciplinary integrated diagnostic approach was used to diagnose and confirm a neoplastic pleural effusion due to osteosarcoma metastasis in a dog.     

Imprint and brush cytology in the diagnosis of canine intranasal tumours

Fifty-four dogs with nasal tumours were included in this study. Based on histopathology, 52 tumours were malignant (36 epithelial and 16 mesenchymal) and two were benign (one oncocytoma and one pleiomorphic adenoma). Malignancy was significantly more frequently diagnosed by imprint cytology (81 per cent of the cases) than by brush cytology (56 per cent). Brush cytology was a significantly more sensitive technique in epithelial than in mesenchymal tumours, while the sensitivity of imprint cytology was not affected by the histological type. Brush cytology determined an epithelial origin in 88 per cent of epithelial tumours, and imprint cytology in 90 per cent. In mesenchymal tumours, the scores were significantly lower, the histological type being determined in only 20 per cent and 50 per cent, using brush and imprint cytology, respectively.     

Cutaneous metastasis of primary appendicular osteosarcoma in a dog

A 6-year-old, neutered male Rottweiler was presented to the University of Illinois Veterinary Teaching Hospital because of a lytic bone lesion involving the distal portion of the right radius and possible pulmonary metastases on thoracic radiographs. Results of serum biochemical analysis were unremarkable. Aspiration and cytologic examination of the bone lesion indicated likely sarcoma with reactive bone. Cutaneous masses were found on the left thigh, interscapular region, and dorsal lumbar region, 4 weeks after initial presentation. Neoplastic spindle cells were found in aspirates from 2 of the masses. The neoplastic cells stained positive for alkaline phosphatase activity using cytochemistry. Re-evaluation of serum biochemical values at this time revealed a marked increase in alkaline phosphatase activity (413 U/L, reference interval 12-110 U/L) compared with the initial value (26 U/L). Due to progressive disease, the dog was euthanized and a necropsy was performed. Histologic findings included primary osteosarcoma of the distal portion of the right radius, with metastases in the lungs, spleen, left fourth and fifth ribs, soft tissue of the right medial thigh, and T1-T3/interscapular region. Cutaneous metastasis of primary appendicular osteosarcoma has been reported rarely in animals and humans. Increased serum alkaline phosphatase activity may be a potential indicator of poor prognosis for this neoplasm.     

Incidence and prognostic importance of lymph node metastases in dogs with appendicular osteosarcoma: 228 cases (1986-2003)

OBJECTIVE: To determine the incidence of regional lymph node metastasis in dogs with appendicular osteosarcoma and determine whether regional lymph node metastasis was associated with shortened disease-free interval or survival time. DESIGN: Retrospective study. ANIMALS: 228 dogs with appendicular osteosarcoma in which regional lymph nodes were examined histologically at the time of limb amputation. PROCEDURE: Information collected from the medical records included signalment; affected site; initial serum alkaline phosphatase activity; whether treatment involved adjuvant chemotherapy and, if so, chemotherapeutic agents administered and number of treatments; disease-free interval; and survival time. RESULTS: 10 (4.4%) dogs had histologic evidence of regional lymph node metastasis at the time of amputation. Median disease-free interval for dogs without regional lymph node metastasis (238 days; range, 0 to 1,067 days) was significantly longer than median disease-free interval for dogs with regional lymph node metastasis (48 days; range, 2 to 269 days). Median survival time for dogs without lymph node metastasis (318 days; range, 20 to 1,711 days) was significantly longer than median survival time for dogs with lymph node metastasis (59 days; range, 19 to 365 days). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that regional lymph node metastasis is rare in dogs with appendicular osteosarcoma but that dogs with lymph node metastasis have a poorer prognosis than do dogs without.     

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.     

Evaluation of brush cytology in the diagnosis of chronic intranasal disease in cats

Brush cytology was used as a diagnostic aid in 85 cats affected with chronic intranasal disease. Fifty-three of these cases, sampled over a five-year period, were included in this study, while the other cases were excluded due to poor cellularity of the cytological samples (nine cases) or a lack of histological or follow-up data (23 cases). Thirty-six brush samples were classified by cytology as inflammatory. Subsequent histological examination revealed a false negative diagnosis of neoplasia in six cats, two of which had malignant tumours (one adenocarcinoma and one lymphoma), the remaining four having benign tumours (two adenomas and two osteochondromas). Seventeen samples were classified by brush cytology as neoplastic. This was confirmed in 16 of these cases by histology or follow-up (nine epithelial malignant tumours, six lymphomas and one osteosarcoma). In the remaining case, a false positive diagnosis of lymphoma was made. The procedure had an overall 86.8 per cent (46/53) agreement between the diagnosis of inflammatory conditions versus neoplasia, with a sensitivity of 72.7 per cent, a specificity of 96.8 per cent, a predictive value of a positive test of 94.1 per cent and a predictive value of a negative test of 83.3 per cent.     

Urine N-telopeptide excretion in dogs with appendicular osteosarcoma

Canine appendicular osteosarcoma (OSA) is a commonly diagnosed cancer that is capable of inducing pathologic bone remodeling. Investigating surrogate indices of bone metabolism may contribute to the diagnostic and therapeutic management of bone malignancies in companion animals. This study evaluated the excretion of N-terminal telopeptide (NTx), a marker of bone resorption that is detected in urine. Sixty-three dogs with appendicular OSA were compared with 29 age-matched healthy dogs. Dogs with appendicular OSA had significantly higher baseline urine NTx excretion than healthy controls (P < .0001). In 17 dogs with OSA treated with either amputation or standardized palliative therapies, significant reductions in urine NTx excretion were observed, suggesting that excessive bone resorption in dogs with OSA may be linked with focal skeletal osteolysis or its consequences. To identify any relationship between indicators of pathologic bone turnover, baseline urine NTx excretion was correlated with serum bone alkaline phosphatase (bALP) or radiographic tumor lengths at diagnosis. No significant correlations were identified between baseline urine NTx excretion and either bALP or tumor length. The findings from this study suggest that high urinary NTx excretion may support the diagnosis of focal skeletal osteolysis in dogs, and reductions in urine NTx excretion after treatment may reflect elimination or minimization of pathologic bone resorption.     

The Association of Endothelin‐1 Signaling with Bone Alkaline Phosphatase Expression and Protumorigenic Activities in Canine Osteosarcoma

Background

Canine osteosarcoma (OS) is an aggressive sarcoma characterized by pathologic skeletal resorption and pulmonary metastases. A number of negative prognostic factors, including bone alkaline phosphatase, have been identified in dogs with OS, but the underlying biologic factors responsible for such observations have not been thoroughly investigated. Endothelin‐1‐mediated signaling is active during bone repair, and is responsible for osteoblast migration, survival, proliferation, and bone alkaline phosphatase expression.

Hypothesis

The endothelin‐1 signaling axis is active in canine OS cells, and this pathway is utilized by malignant osteoblasts for promoting cellular migration, survival, proliferation, and bone alkaline phosphatase activities.

Animals

45 dogs with appendicular OS.

Methods

The expressions of endothelin‐1 and endothelin A receptor were studied in OS cell lines and in samples from spontaneously occurring tumors. Activities mediated by endothelin‐1 signaling were investigated by characterizing responses in 3 OS cell lines. In 45 dogs with OS, bone alkaline phosphatase concentrations were correlated with primary tumor osteoproductivity.

Results

Canine OS cells express endothelin‐1 and endothelin A receptor, and this signaling axis mediates OS migration, survival, proliferation, and bone alkaline phosphatase activities. In OS‐bearing dogs, circulating bone alkaline phosphatase activities were positively correlated with primary tumor relative bone mineral densities.

Conclusions and Clinical Importance

Canine OS cells express endothelin‐1 and functional endothelin A receptors, with the potential for a protumorigenic signaling loop. Increases in bone alkaline phosphatase activity are associated with osteoblastic OS lesions, and might be an epiphenomenon of active endothelin‐1 signaling or excessive osteoproduction within the localized bone microenvironment.     

CAN SONOGRAPHIC FINDINGS PREDICT THE RESULTS OF LIVER ASPIRATES IN DOGS WITH SUSPECTED LIVER DISEASE?

While abdominal ultrasound and ultrasound-guided fine-needle aspiration cytology are often combined to help determine the type of liver disease in dogs, little is known about the relationship that may exist between the results of these tests. We hypothesized that specific sonographic findings, or combinations of findings, may predict results of liver ultrasound-guided fine-needle aspiration cytology. Hepatic and extrahepatic sonographic findings were recorded prospectively using a standardized form in 70 dogs with clinically suspected liver disease and in which liver ultrasound-guided fine-needle aspiration cytology was performed. The predictive value of sonographic findings in regard to the category of cytology results was assessed with stepwise logistic regression analysis. Sonographic detection of a hepatic mass (≥3 cm; risk ratio [RR] 3.83, 95% Wald confidence intervals [95% CI] 2.42–3.93, P =0.0036), ascites (RR 3.82, 95% CI 1.94–4.28, P =0.0044), abnormal hepatic lymph node(s) (RR 3.01, 95% CI 1.22–4.88, P =0.0262), and abnormal spleen (RR 3.26, 95% CI 1.20–3.85, P =0.0274) were the most predictive of liver neoplasia on cytology. Conversely, sonographic detection of hepatic nodules (<3 cm; RR 1.97, 95% CI 0.95–2.96, P =0.0666) was most predictive of vacuolar hepatopathy on cytology. In dogs with suspected liver disease, several sonographic findings, alone or combined, are thus predictive of liver ultrasound-guided fine-needle aspiration cytology results. In the light of the fact that ultrasound-guided fine-needle aspiration cytology of the liver has limitations, these predictabilities could influence the selection of diagnostic tests to reach a reliable diagnosis.     

Prevalence of Fasciola hepatica in dairy herds in England and Wales measured with an ELISA applied to bulk-tank milk

An ELISA developed to diagnose Fasciola hepatica infection in cattle by detecting serum antibodies was adapted and validated for use with samples of bulk-tank milk. The prevalence of the infection in 61 dairy herds was established by using serum antibody levels or faecal egg counts measured in a proportion of the cows in each herd. The correlation between the results of the ELISA and the herd seroprevalence was 0.83. Using a cut-off value of 27 per cent positive, the bulk-tank ELISA identified herds in which more than 25 per cent of the cows were infected with a diagnostic sensitivity of 96 per cent (95 per cent confidence interval 89 to 100 per cent) and a diagnostic specificity of 80 per cent (95 per cent confidence interval 66 to 94 per cent). By applying the ELISA to 623 herds in England and 445 herds in Wales, the prevalence of F hepatica infection in England was estimated to be 48 per cent (95 per cent confidence interval 46 to 54 per cent), and in Wales 86 per cent (95 per cent confidence interval 84 to 90 per cent).     

Diagnosis, treatment and outcome of orbital neoplasia in dogs: a retrospective study of 44 cases

Forty-four dogs with confirmed orbital neoplasia were studied. Eighteen tumour types were represented and 95 per cent of the neoplasms were classified as malignant. The tumour types most commonly diagnosed were osteosarcoma, fibrosarcoma and nasal adenocarcinoma. Thirty-six per cent of the dogs had at least one clinical sign that was compatible with a diagnosis of orbital abscessation or cellulitis. Fifty-six per cent of the dogs, where follow-up information was available, were euthanased or had died within six months of diagnosis, while 19 per cent of the total were still alive after one year post-diagnosis. Cytological examination was diagnostic for orbital neoplasia in 49 per cent of the fine needle aspirates of the retrobulbar space. In contrast, 56 per cent of the non-surgical biopsies were diagnostic for orbital neoplasia. Of those dogs that had died or been euthanased within six months of diagnosis, only 22 per cent had undergone some form of therapy for orbital neoplasia. In comparison, 86 per cent of dogs surviving longer than six months post-diagnosis had undergone such therapy.     

Percutaneous biopsy of abdominal organs under ultrasound guidance

Percutaneous sampling of one or more abdominal organs was performed under ultrasound guidance in 89 dogs and 16 cats. Tissue core samples were considered to be of diagnostic quality in 92 per cent of hepatic and 100 per cent of renal biopsies. Core biopsies were collected from the prostate in only three cases but each was adjudged of diagnostic quality. The technique allowed a definitive diagnosis or normal tissue to be confirmed in 65 per cent of animals undergoing hepatic biopsy, 83 per cent undergoing renal biopsy and 82 per cent undergoing prostatic biopsy or aspiration. Few complications occurred which could be ascribed with certainty to the procedure. One dog with extensive hepatic necrosis died one week after the biopsy, but necropsy examination was denied. One severely debilitated cat did not recover from general anaesthesia. One dog underwent aspiration of a sterile intraprostatic cyst, and developed prostatic abscessation one week later; prostatic carcinoma was subsequently found. Careful selection and preparation of patients for biopsy are essential. With this caveat, ultrasound-guided sampling of abdominal organs is a useful technique allowing a definitive diagnosis in a high proportion of cases. The technique is minimally invasive and the complication rate low.     

P-64 Cutaneous epitheliotropic lymphoma in a dog: treatment with oral pentoxifylline

Osteosarcoma is a malignant mesenchymal neoplasm characterized by the formation of osteoid tissue. It is the most frequent primary bone tumour in dogs, accounting for nearly 80–85% of all reported long bone appendicular osteosarcomas. Conversely, in cats and other species, osteosarcoma is rare at any site. Extraskeletal osteosarcoma (EOS) is a malignant, osteoid-producing neoplasm without primary periosteal or bone involvement. These tumours have been described less frequently and occur mainly in the mammary glands of female dogs. Case material was obtained from biopsy records of the Pathology Service at the Veterinary School, Universidad Nacional. The diagnosis of these tumours was based on the absence of clinical, radiological, or pathological evidence of primary bone or glandular involvement. Samples were processed for histopathological examination and stained with H&E. In two cases, immunohistochemistry was performed. Eleven cases were diagnosed with EOS located in two histological locations. The dermal group consisted of three female dogs (two Rottweillers and one Fila Brasileiro), one male German shepherd (mean age of dogs: 5.5 years), two female cats (mixed-breed and Siamese) of 5 and 11 years of age, respectively, and one 4-year-old female ferret. The subcutaneous group consisted of four dogs, two female pit bull terriers and two male dogs (boxer and mixed-breed), with a mean age of 5 years. The subcutaneous EOS tumours were more aggressive. Three dogs were euthanized due to lung metastasis and the remaining dog was lost to follow-up.
Funding: Self-funded.     

P‐62 Dermal and subcutaneous extraskeletal osteosarcomas in eight dogs,two cats,and one ferret

Osteosarcoma is a malignant mesenchymal neoplasm characterized by the formation of osteoid tissue. It is the most frequent primary bone tumour in dogs, accounting for nearly 80–85% of all reported long bone appendicular osteosarcomas. Conversely, in cats and other species, osteosarcoma is rare at any site. Extraskeletal osteosarcoma (EOS) is a malignant, osteoid‐producing neoplasm without primary periosteal or bone involvement. These tumours have been described less frequently and occur mainly in the mammary glands of female dogs. Case material was obtained from biopsy records of the Pathology Service at the Veterinary School, Universidad Nacional. The diagnosis of these tumours was based on the absence of clinical, radiological, or pathological evidence of primary bone or glandular involvement. Samples were processed for histopathological examination and stained with H&E. In two cases, immunohistochemistry was performed. Eleven cases were diagnosed with EOS located in two histological locations. The dermal group consisted of three female dogs (two Rottweillers and one Fila Brasileiro), one male German shepherd (mean age of dogs: 5.5 years), two female cats (mixed‐breed and Siamese) of 5 and 11 years of age, respectively, and one 4‐year‐old female ferret. The subcutaneous group consisted of four dogs, two female pit bull terriers and two male dogs (boxer and mixed‐breed), with a mean age of 5 years. The subcutaneous EOS tumours were more aggressive. Three dogs were euthanized due to lung metastasis and the remaining dog was lost to follow‐up. Funding: Self‐funded.