Primary and metastatic carcinomas in the digits of cats

In the period 1993-1998, digital carcinomas in 64 cats were examined. In all animals primary complaints were painful digit(s). Eight cats had a primary squamous cell carcinoma which involved one digit or two adjacent digits of one leg. Fifty-six cats had metastases of a pulmonary carcinoma in the digits, and in general multiple digits of different legs were involved. In many of these cats metastases also occurred in other organs, including the skin and muscles. No primary sweat gland carcinomas of the digits were seen. Primary squamous cell carcinomas of the digits were characterized by cornification and the absence of PAS-positive cells, PAS-positive secretory material. Immunohistochemically, these neoplasms stained negative with the monoclonal antibody CAM 5.2 directed against Keratin 8 (K 8). The metastases of pulmonary carcinomas to the digits showed one or more of the following histological features: goblet cells, ciliated epithelial cells, PAS-positive cells or lakes, and/or a PAS-positive lining of luminal membranes and no cornification. Immunohistochemically, they showed positive staining for CAM 5.2 (K8). Thoracic radiographs from three cats with a primary squamous cell carcinoma showed no abnormalities, whereas all cases of metastases from a pulmonary carcinoma to the digits available for follow-up showed evidence of a primary pulmonary carcinoma on radiography and/or postmortem examination (25 out of 56). The conclusion of this study was that most carcinomas in the digits of cats were metastases of a primary pulmonary carcinoma (87.5%). Primary squamous cell carcinomas occurred infrequently. The prognosis of metastases of a pulmonary carcinoma in the digits is poor with an average survival time of 4.9 weeks, in contrast to 29.5 weeks in cats with a squamous cell carcinoma. These data stress the importance of taking thoracic radiographs of cats with digital tumours before surgical intervention.     

Diagnoses and clinical outcomes associated with surgically amputated feline digits submitted to multiple veterinary diagnostic laboratories

Amputation is commonly performed in an attempt to both treat and diagnose conditions affecting the digits of cats. The records of multiple veterinary diagnostic laboratories were searched to identify submissions of amputated digits from cats. Eighty-five separate submissions were reviewed for diagnosis, age, sex, limb of origin, and digits affected; and the original submitting clinics were surveyed to determine clinical outcome. The Kaplan-Meier product-limit method was used to determine the disease-free interval and survival time. Neoplastic disease was identified in 63 of 85 submissions, with exclusively inflammatory lesions composing the other 22 cases. In 60 (95.2%) of the neoplastic cases, a malignant tumor was identified. Squamous cell carcinoma was the most commonly identified malignant tumor (n = 15; 23.8%) and was associated with a median survival time of 73 days. Other diagnoses included fibrosarcoma (n = 14; 22.2%); adenocarcinoma, likely metastases of a primary pulmonary neoplasm (n = 13; 20.6%); osteosarcoma (n = 5; 7.9%); mast cell tumor (n = 4; 6.3%); hemangiosarcoma (n = 5; 7.9%); malignant fibrous histiocytoma (n = 2; 3.2%); giant cell tumor of bone (n = 2; 3.2%); and hemangioma (n = 2; 3.2%). Giant cell tumor of bone has not been previously described in the digits of cats. Various neoplasms can occur in the digits of cats, and submission of the amputated digit for histopathologic diagnosis is essential to determine the histogenesis and predict the clinical outcome.     

Feline cutaneous fibropapillomas: clinicopathologic findings and association with papillomavirus infection

Twenty-three feline cutaneous fibropapillomas with histologic features similar to equine sarcoids were diagnosed. They were characterized by dermal fibroblastic proliferation with overlying, often ulcerated hyperplastic epidermis. Electron microscopic findings supported the fibroblastic nature of the neoplastic cells. The 23 tumors came from 20 cats and were submitted from veterinary clinics in Wisconsin and Minnesota. These tumors occurred most commonly in young cats and were found primarily on the head, neck, and digits. Fifteen of the 17 cats for which breed was reported were domestic shorthair cats. In 11/20 cases, there was confirmed exposure to cattle. Local recurrence of the tumor following surgical excision was reported in 7 of the 18 cats for which follow-up information was available. Metastasis was not documented in any of the cases. Two of the 19 tumors tested by polymerase chain reaction (PCR) had no amplifiable DNA. The remaining 17 were positive for papillomavirus by PCR. No papillomavirus DNA was detected in three other feline skin tumors (cutaneous mast cell tumor, malignant lymphoma, and fibrosarcoma) that served as controls. This is the first report of detection of papillomavirus in feline tumors that have clinicopathologic features similar to equine sarcoids.     

Immunodiagnosis of autoimmune skin disease in the dog, cat and horse

Skin biopsies from 47 dogs, 6 cats and 5 horses with suspected autoimmune skin disease were submitted for immunofluorescence from 1978 to 1985. These cases were predominantly Western Australian in origin, although a number were also referred from Queensland and Victoria. In 5 dogs, 2 cats and 2 horses immunoglobulin binding to intercellular cement substance and/or basement membrane was demonstrated by direct immunofluorescence. Antinuclear antibody was also demonstrated in several of these cases. Immunofluorescence was used in combination with histopathological examination to confirm the clinical diagnosis of autoimmune disease in 19/47 dogs, 4/6 cats and 2/5 horses. There was no age, breed or sex predisposition amongst the 19 positive dogs, however there was a higher incidence of antinuclear antibody (54%) than the normal canine population (10%) and other autoantibodies (rheumatoid factor) were sometimes present. Abnormalities in serum protein electrophoresis and serum complement C4 levels were also recorded in this group.     

Diagnoses and clinical outcomes associated with surgically amputated canine digits submitted to multiple veterinary diagnostic laboratories

Amputation is commonly performed to both treat and diagnose conditions affecting the digits of dogs. Although histopathologic evaluation of these digits is routinely done, data on the prevalence and prognosis of neoplasms of the digit are scarce. The records of multiple veterinary diagnostic laboratories were searched to identify submissions of amputated digits from dogs. Four hundred twenty-eight separate submissions were reviewed for diagnosis, age, sex, limb of origin, and digits affected, and the original submitting clinics were surveyed to determine clinical outcome of the animal. No diagnosis could be agreed upon in 24 animals, and these were excluded from the study. Kaplan-Meier product-limit method was used to determine the disease-free interval and survival time. Neoplastic disease was identified in 296 of 404 submissions, with exclusively inflammatory lesions composing 108 cases. A total of 30 different neoplastic processes were identified. In 233 (77.7%) of the neoplastic cases, a malignant tumor was identified. Squamous cell carcinoma was the most commonly identified tumor (n = 109, 36.3%), and 11 of 42 dogs for which clinical follow-up information was available developed metastatic disease. Squamous cell carcinoma of the digit appears to have a greater metastatic potential than that occurring elsewhere in the body. Other common diagnoses included melanoma (n = 52, 17.3%), soft-tissue sarcoma (n = 29, 9.7%), and mast cell tumor (n = 20, 6.7%). Melanomas were associated with poor prognoses, with a median survival time of 365 days.     

Heart failure is common in diabetic cats: findings from a retrospective case-controlled study in first-opinion practice

OBJECTIVES: To study the prognosis and cause of death in cats with diabetes mellitus. METHODS: Twenty consecutive cases of feline diabetes mellitus diagnosed in first-opinion practice were followed. Three control cats, without diabetes, were matched to each case of diabetes; these were also followed. RESULTS: One Somali cat with diabetes could not be matched, so complete data analysis considered only 19 diabetics and 57 matched controls. Death occurred in 14 of 20 diabetics and 23 of 57 controls although one control cat was eventually lost to follow-up. Heart disease and heart failure led to death in six diabetic cats. One of these was the non-matched Somali; nevertheless, the death rate from heart disease in the diabetics was five of 19 compared with two of 57 in controls. The relative risk of heart failure in diabetic cats was 10.4 times that of the controls; this difference in rates was statistically significant. Survival amongst diabetics was significantly worse than for controls. For the control cats median survival was 718 days after the index visit, whereas for the diabetic cases median survival was 385 days after diagnosis. CLINICAL SIGNIFICANCE: Heart disease and failure are common in diabetic cats. This observation deserves further attention.     

Efficacy of doxorubicin as an induction agent for cats with lymphosarcoma

OBJECTIVE: To determine the efficacy of doxorubicin when used alone in inducing remission in cats with lymphosarcoma. DESIGN: Prospective multi-institutional study of naturally occurring disease. METHODS: Cases were accrued from veterinary institutions in Australia and New Zealand after obtaining consent from informed owners. Cats were treated with doxorubicin every 3 weeks for three treatments. If there was no response to the first dose of doxorubicin or if the cat relapsed during the doxorubicin regimen, the cat was withdrawn from the trial and either euthanased or treated with other agents. Age, breed, gender and anatomic site of the lymphosarcoma (multicentric, alimentary, mediastinal, extranodal) were recorded for each cat. Clinical remission was assessed before each treatment by physical examination, radiography, ultrasonography and computed tomography where appropriate. Complete remission was defined as the disappearance of all clinical signs and clinically detectable tumour. RESULTS: Twenty-one cases were accrued over a 2-year-period but only 19 were available for data analysis. Young Siamese cats were over-represented and all cats with mediastinal tumours were young Siamese. There was a significant difference between the mean ages of cats with mediastinal or multicentric lymphosarcoma (mean +/- SD: 3.5 +/- 3.0 and 4.3 +/- 2.6 years, respectively) and cats with alimentary or extranodal LSA (11.4 +/- 0.9 and 11.0 +/- 0.9 years, respectively). Of 19 cats treated with doxorubicin alone, 6 (32%) had complete remission, 6 (32%) had partial remission and 7 (36%) did not respond. CONCLUSIONS: The results suggest that doxorubicin cannot be recommended as a single agent for treatment of feline lymphosarcoma because of the rather poor remission rate achieved.     

Demodex cati infestation in association with feline cutaneous squamous cell carcinoma in situ: a report of five cases

Demodex cati infestation was identified at lesional sites of multicentric squamous cell carcinoma in situ (Bowen's disease) in five elderly domestic shorthaired cats. Lesions were observed on the face, neck, shoulders, stifles and limbs. Deep skin scrapings taken from lesional skin contained D. cati eggs, larvae and adults in four cases. D. cati were discovered histologically in four cases. Histopathology of skin biopsy specimens confirmed the diagnosis of squamous cell carcinoma in situ in all cases. Serology for feline immunodeficiency virus (FIV) was positive in three cats. Remission of Bowen's disease lesions was obtained in 4–6 months using oral retinoids etretinate (one case) or acitretin (one case). It is suspected that local immunodeficiency due to epithelial dysplasia might have predisposed the skin to a focal multiplication of D. cati. Alternatively, FIV infection may have led to immune suppression predisposing the cats to both papillomavirus-induced epithelial dysplasia and D. cati infestation.     

Monoparesis in association with feline pulmonary carcinoma: A literature review with 3 new cases

We describe 3 cases of cats that were presented with a sudden onset of monoparesis as a result of arterial thromboembolism without evidence of cardiovascular disease that were subsequently diagnosed with a primary pulmonary carcinoma. Arterial tumor thromboemboli due to pulmonary carcinoma should be considered as a differential diagnosis in cases of lameness or paresis in older cats. We theorize that large tumor emboli may obstruct peripheral arteries leading to acute monoparesis.     

Clinical characteristics of mammary carcinoma in male cats

There is little information regarding mammary tumors in male cats. The purpose of this study was to characterize the clinical characteristics of mammary carcinoma in male cats, compare this malignancy to the disease in female cats, and identify prognostic factors. Thirty-nine male cats with mammary carcinoma were identified. One pathologist reviewed the biopsies from all cats, and complete follow-up information regarding outcome was available for 27 cats. Information collected included signalment, age at neutering, history of progestin therapy, age at tumor diagnosis, size of tumor, type of surgery (lumpectomy, simple mastectomy, or radical mastectomy), results of clinical staging, adjunctive therapies, time to local recurrence, survival, and cause of death. The mean age at tumor diagnosis (12.8 years) was slightly older than that reported in female cats. The incidence of local tumor recurrence in 9 of 20 (45%) cats was similar to that reported in females. A history of progestin therapy was present in 8 of 22 (36%) cats for which this information was known. The median time to local recurrence was 310 days (range 127-1,363 days), and overall median survival was 344 days (range 14-2,135 days). Tumor size and lymphatic invasion were identified as negative prognostic factors. This study indicates that mammary carcinoma in the male cat has many similarities to the disease in females, with an aggressive clinical course in most cats.     

Multiple squamous cell carcinoma of the digits in two cats

This paper describes the clinical and pathological features of two cats with squamous cell carcinoma affecting several digits. Similar lesions have been described in dogs and humans.     

Coccidioidomycosis in 48 Cats: A Retrospective Study (1984–1993)

Coccidioidomycosis was diagnosed in 48 cats. Forty-one cases were identified within a period of 3 years. Coccidioides immitis was revealed by cytological or histopathological examinations, or culture in 70% of cats. The remaining 30% of cases were diagnosed by appropriate clinical signs, radiographic lesions, and serological test results. The average age of affected cats was 6.2 years with a median age of 5.0 years. Fifty-four percent (n = 26) were female and 46% (n = 22) were male. Domestic shorthaired and longhaired breeds comprised 89% (n = 41) of affected cats. Sixty-seven percent of cases were diagnosed during the 6-month period of December through May. Cats infected with C immitis were presented for evaluation of dermatologic (56%), respiratory (25%), musculoskeletal (19%), and neurological or ophthalmologic signs (19%). Fever, inappetence, and weight loss were present in 44% of the cats. Duration of clinical signs before diagnosis was less than 4 weeks in 85% (n = 42) of cats, with an average of 3.8 weeks and a median of 2 weeks. Agar gel immunodiffusion tests were positive in all 39 cats tested at sometime during the course of their disease. Hyperproteinemia (greater than 7.9 g/dL) was present in 52% (10/23) of cases. The majority of cats (n = 39) were negative for feline leukemia virus. Antibodies to feline immunodeficiency virus were absent in the 19 cats tested. Ketoconazole was the most common antifungal agent used to treat cats with Coccidioidomycosis. Duration of treatment ranged from less than 1 week to 43 months. Thirty-two cats are currently asymptomatic, with or without treatment. Eleven cats died or were euthanized. Five cats were lost to follow-up. Ketoconazole likely is more suppressive than curative because relapses were common after discontinuing therapy.     

Cutaneous neoplasia in 340 cats.

A total of 340 cases of cutaneous neoplasia were diagnosed in 340 of 3,564 cats that were examined by biopsy or necropsy during a 41-month period from January 1, 1986 through May 31, 1989. Eighteen types of tumor occurred, but four types comprised 77% of the cases. These were basal cell tumor, 89 cases (26%, mean age 10.3); mast cell tumor, 72 cases (21%, mean age 8.6); squamous cell carcinoma, 52 cases (15%, mean age 11.6); and fibrosarcoma, 50 cases (15%, mean age 10.2). For each of these four types of tumors, peak number of cases occurred in cats older than 10 years. Mast cell tumor was the only tumor diagnosed in cats younger than 1 year. The head was the most common site for basal cell tumors, mast cell tumors, and squamous cell carcinomas. The legs were the most common location of fibrosarcomas. Siamese cats had approximately three times as many mast cell tumors as statistically expected, but only one-fourth as many squamous cell carcinomas. Breed predilection for other skin tumors was not apparent. Sex predilection was not detected for any skin tumor.     

Treatment of mandibular squamous cell carcinoma in cats by use of mandibulectomy and radiotherapy: seven cases (1987-1989).

Seven cats with squamous cell carcinoma involving the mandible were treated by surgery and radiotherapy. Surgery consisted of hemimandibulectomy or combined rostral and hemimandibulectomy, gastrostomy tube placement, and submandibular lymph node excisional biopsy. Radiotherapy (orthovoltage or 60Co) commenced 2 weeks after surgery. Histologically, the tumor invaded surgical margins in 6 of 7 cats. Nerve infiltration was histologically identified in 2 cats. All cats had stage-3 disease with radiographic evidence of mandibular bone involvement. Age ranged between 8 and 16 years (median, 10 years). Hypercalcemia (2), feline immunodeficiency virus (2), and hyperthyroidism (1), were detected in cats prior to treatment. Survival after surgery was a median of 14 months (range = 3 to 36 months, mean = 15 months). Six cats were euthanatized because of recurrence of disease at 3, 7, 9, 16, 21, and 36 months. One cat was euthanatized at 14 months because of an unrelated disease. Complications of tongue lagging, drooling after meals, mandibular drift, maxillary ulceration, and alopecia of the jaw developed in a few cats. Radiation at the primary site and regional lymph nodes after surgery of curative intent extended survival in cats with mandibular squamous cell carcinoma.     

RESPONSE OF FELINE ORAL SQUAMOUS CELL CARCINOMA TO PALLIATIVE RADIATION THERAPY

Seven cats with advanced oral squamous cell carcinoma were treated with palliative radiotherapy. Megavoltage radiation in 8 Gray (Gy) fractions was delivered on days 0, 7, and 21 for a total dose of 24 Gy. Treatment field included the mandible, oropharynx, retropharyngeal lymph nodes, and tonsils. Adjuvant treatment with chemotherapy was variable. Age ranged from 13 to 18 years old with a median age of 15 years. Three of the seven cats (43%) did not complete treatment. Six cats were euthanized due to tumor growth and/or radiation side effects with a median survival time of 60 days (range = 42 to 97 days, mean = 63 +/- 8.4 days). Radiotherapy complications or progression of disease occurred in 6 of 7 (85.7 %) cats and included adverse clinical signs, such as mucositis, serosanguinous oral discharge, pain, and dysphagia. These data suggest that coarse fractionation radiotherapy did not result in palliation in cats with inoperable oral squamous cell carcinoma.     

Tidal Breathing Flow-Volume Loops in Healthy and Bronchitic Cats

Tidal breathing flow-volume loops (TBFVL) were obtained from 19 healthy cats and 7 cats with chronic bronchial disease. Peak inspiratory flow (PIF) occurred late in the inspiratory cycle and was preceded by a gradual but more linear increase in the flow rate. Peak expiratory flow (PEF) occurred early during expiration and was followed by a curvilinear decrease in flow to a point near the end of expiration where flow ceased. The loops obtained were generally reproducible. The mean coefficient of variation (CV) for TBFVL indices of healthy cats ranged from 5.6% to 21.9%. Loop indices from cats with chronic bronchial disease had a mean CV between 6.6% and 28.4%. Significant differences were noted in the bronchitic cats' TBFVLs, including an increased ratio of expiratory time to inspiratory time, lower expiratory flow rates, decreased area under total and peak expiratory flow curves, and decreased tidal breathing expiratory volumes (TBEV) at 0.1 and 0.5 seconds. Selected TBFVL indices were also significantly reduced. TBFVL evaluation in the cat is easy to perform, is reproducible, and has allowed for the detection of changes during tidal breathing in cats with histories and physical findings of chronic lower airway disease. (Journal of Veterinary Internal Medicine 1993; 7:388–393. Copyright © 1993 by the American College of Veterinary Internal Medicine.)     

Serum and Plasma Vascular Endothelial Growth Factor Levels in Various Cat Populations

Introduction:  Vascular endothelial growth factor (VEGF) is one of the most important mediators of angiogenesis. Elevated levels within tumors, and in serum, plasma, and tumor effusion have been correlated with the development of metastatic disease, recurrence, and poor prognosis in many tumors in humans. Canine VEGF has been sequenced as homologous with the human form, and elevated serum and plasma VEGF have been found in dogs with hemangiosarcoma. Feline VEGF has also been sequenced, and shares homology with the human and canine forms.
Materials and Methods:  Stored serum and plasma samples from normal cats, cats with various neoplasms, and cats with non‐neoplastic disease were evaluated with a commercial ELISA kit (R&D Systems, Minneapolis MN). Samples were run in duplicate, and a standard curve was performed for each plate. The data were analyzed for differences between populations, and between serum and plasma levels in the same patient to determine the optimal sample for evaluating VEGF in cats.
Results:  In seven apparently healthy cats mean plasma VEGF was 95.6 pg/mL. In non‐neoplastic disease (7 cases), mean plasma VEGF was 117.3 pg/mL and mean serum VEGF level was 219.7 pg/mL. In ten tumor‐bearing patients mean plasma VEGF was 247.1 pg/mL, and mean serum VEGF was 322.3 pg/mL. Statistical analysis showed no significant difference between mean serum and plasma VEGF concentrations within each group or between groups (p > 0.05).
Discussion:  Serum and plasma VEGF levels could not be used to distinguish between healthy cats and cats with neoplastic or non‐neoplastic disease.     

Feline early life ocular disease

Objectives Histomorphologic changes in six globes from six cats, which experienced early life ocular disease of undetermined etiology, are described. Design A retrospective morphologic study of six eyes from six cats with early life ocular surface disease of unknown etiology, from 2002 to 2006 extracted from a pathology collection, which includes 2200 feline submissions. Procedure Sections of affected globes, stained with H&E were examined with a light microscope. Results The mean age of the affected cats, at the time of enucleation, was 7.5 months ranging from 7 weeks to 2 years. The cats were one male, one female, one male neutered, and one female spayed cat. For the remaining two cats the sex was not known. All cats were DSH. Significant histomorphologic findings included collapse of the globe in all cases and a broad corneal perforation with protrusion of the anterior uvea, which was epithelialized in all cases. Three cases revealed uveal hematopoiesis in the anterior and posterior uvea. All cases had recognizable corneal tissue at the limbus on both sides. Inflammation in all cases consisted of variable but generally mild uveitis and no eyes had endophthalmitis. Four of the globes had no recognizable lens tissue. Three of the cats had symblepharon formation described as part of the clinical condition. The other three cases had no mention of symblepharon. Conclusions These cases are considered to represent changes associated with early life corneal ablation of unknown etiology. Uveal prolapse, mild inflammation, and symblepharon are considered to be either secondary or caused by the same destructive primary event that affected the cornea. These cases are the first cases we are aware of with uveal extramedullary hematopoiesis in cats. Careful consideration of cell morphology is necessary to distinguish this condition from round cell neoplasms or inflammation.     

Prostatic carcinoma in two cats

Clinical, radiological and pathological features of two cats with prostatic carcinoma are reported. In both cats the presenting history included signs of lower urinary tract disease with haematuria and dysuria. Prostatomegaly was visible radiographically in one cat; an irregular intraprostatic urethra was seen on retrograde contrast urethrography in both cats. In one of the cats, neoplasia was suspected on the basis of a transurethral catheter biopsy. Following a poor response to palliative treatment in both cases, euthanasia was performed with histological confirmation of the diagnosis.