COMPUTED TOMOGRAPHIC FINDINGS IN 57 CATS WITH PRIMARY PULMONARY NEOPLASIA

Primary pulmonary neoplasia is relatively uncommon in cats and generally has a poor prognosis. In this multicenter, retrospective study of 57 cats with pulmonary neoplasia, the most frequent presenting signs were anorexia/inappetence (39%) and cough (37%). The pulmonary tumors were considered to be incidental findings in 9% cats. In computed tomographic (CT) images, primary pulmonary tumors appeared as a pulmonary mass in 55 (96%) cats and as a disseminated pulmonary lesion without a defined mass in two (4%) cats. Most pulmonary tumors were in the caudal lobes, with 28 (49%) in the right caudal lobe and 17 (30%) in the left caudal lobe. CT features associated with pulmonary tumors included mass in contact with visceral pleura (96%), irregular margins (83%), well‐defined borders (79%), bronchial compression (74%), gas‐containing cavities (63%), foci of mineral attenuation (56%), and bronchial invasion (19%). The mean (range) maximal dimension of the pulmonary masses was 3.5 cm (1.1–11.5 cm). Additional foci of pulmonary disease compatible with metastasis were observed in 53% cats. Pleural fluid was evident in 30% cats and pulmonary thrombosis in 12% cats. The histologic diagnoses were 47 (82%) adenocarcinomas, six (11%) tumors of bronchial origin, three (5%) adenosquamous cell carcinomas, and one (2%) squamous cell carcinoma. In this series, adenocarcinoma was the predominant tumor type, but shared many features with less common tumor types. No associations were identified between tumor type and CT features. Prevalence of suspected intrapulmonary metastasis was higher than in previous radiographic studies of cats with lung tumors.     

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.     

A histopathologic study of twenty urinary bladder neoplasms in the cat

Urinary bladder neoplasms were diagnosed in 20 cats during an eight-year period. Histologic types included angioma, intravenous leiomyoma, adenocarcinoma, squamous cell carcinoma, transitional cell carcinoma, leiomyosarcoma, haemangiosarcoma, lymphoma, and embryonal rhabdomyosarcoma. Malignant neoplasms (18/20; 90 per cent) and malignant epithelial neoplasms (12/20; 60 per cent) predominated. Adenocarcinomas and squamous cell carcinomas were almost as common as transitional cell carcinomas. All adenocarcinomas and most transitional cell carcinomas were exophytic, in contrast to all squamous cell carcinomas and most sarcomas which were endophytic. Metaplastic, hyperplastic, and in situ changes in the adjoining mucosa of the bladder were seen commonly in the cases of epithelial neoplasms; Brunn's nests were associated more with the adenocarcinomas than with the other epithelial tumours.     

Presence of p53 mutations in feline neoplasms

A region from exon 4 to 8 of the tumour suppressor gene p53 was analysed in 60 feline tumours (30 fibrosarcomas, seven malignant histiocytomas, three lymphosarcomas, five basal cell tumours, five squamous cell carcinomas, two adenocarcinomas of tubular skin glands, one undifferentiated carcinoma of the skin, seven mammary carcinomas). Missense mutations were detected in two fibrosarcomas, one malignant fibrous histiocytoma, the undifferentiated carcinoma of the skin and one mammary carcinoma. One nonsense mutation was detected in one fibrosarcoma and one deletion/frameshift-mutation was observed in one squamous cell carcinoma.     

An immunohistochemical study of cyclooxygenase-2 expression in various feline neoplasms

Cyclooxygenase (COX) enzymes catalyze the synthesis of prostaglandins and exist as two isoforms, COX-1 and COX-2. COX-2 is a potent inducible mediator of inflammation. COX-2 is also upregulated in several human tumors and in canine squamous cell, renal cell, and transitional cell carcinomas, prostatic adenocarcinoma, and intestinal neoplasia. The purpose of this study was to determine whether COX-2 is expressed in various feline tumors. Results of this study may help determine whether COX-2 is a potential target for therapeutic and preventive strategies in cats. Immunohistochemical studies were performed on paraffin-embedded tissues using the amplified streptavidin-biotin-horseradish peroxidase system. COX-2 was found in 7 of 19 (37%) feline transitional cell carcinomas and in 2 of 21 (9%) feline oral squamous cell carcinomas. No COX-2 immunoreactivity was detected in cutaneous squamous cell carcinomas (6), adenocarcinomas (nine mammary, eight pulmonary, seven intestinal), lymphomas (six nasal, six intestinal), or 10 vaccine-associated sarcomas. The widespread absence of COX-2 expression in most feline neoplasms might suggest that COX-2 inhibitors would have a low potential as anticancer agents.     

COMPARISON BETWEEN CLINICAL,ULTRASOUND, CT,MRI, AND PATHOLOGY FINDINGS IN DOGS PRESENTED FOR SUSPECTED THYROID CARCINOMA

This study compares clinical, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and pathology findings in 16 prospectively, and seven retrospectively recruited dogs presented for suspected thyroid carcinoma. Of these, 17 were confirmed thyroid carcinoma, while six were initially misdiagnosed. These included four carotid body tumors, one para‐esophageal abscess, and one undifferentiated squamous cell carcinoma. Thyroid carcinomas occurred in older dogs without evidence of sex predilection, and were more often unilateral. All were large, heterogeneous, moderately to strongly vascularized, and most commonly contained areas of dystrophic mineralization and/or fluid accumulations. On MRI, thyroid carcinomas appeared hyperintense compared to surrounding musculature in all imaging sequences used, while on CT they had a lower attenuation value than normal thyroid gland tissue. Histologically confirmed tumor capsule disruption with invasion of the surrounding structures was most commonly detected with MRI. Palpation was not an accurate predictor of locally invasive vs. well‐encapsulated masses. Computed tomography had the highest specificity (100%) and MRI had the highest sensitivity (93%) in diagnosing thyroid carcinoma, while ultrasound had considerably lower results. We conclude that ultrasound is adequate for use as a screening tool for dogs with suspected thyroid carcinoma, but recommend either CT or MRI for preoperative diagnosis and staging.     

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.     

A REVIEW OF PRIMARY LUNG TUMORS IN THE DOG AND CAT

Primary pulmonary carcinomas are being encountered with increasing frequency in older dogs and cats. The most common presenting complaint in the canine is a nonproductive cough of several weeks' duration, but many affected animals have no abnormal clinical signs in the early stages of the disease. A solitary mass that arises from a single focus in the peripheral pulmonary tissue is the most frequently observed radiographic sign of a primary lung tumor. Often a definitive diagnosis can be made only following thoracotomy with removal or biopsy study of the neoplastic tissue. A classification system based on the prevailing histologic pattern may then be used to categorize most primary lung neoplasms as adenocarcinomas, squamous cell carcinomas, anaplastic carcinomas, or bronchioloalveolar carcinomas. Adenocarcinomas are most common in the dog and cat. Only the neoplastic cell type and the presence or absence of metastatic disease have been found to be of value as prognostic indicators. Following wide surgical resection of the pulmonary mass, dogs with pulmonary adenocarcinomas are reported to have a longer mean survival time than animals with other types of primary lung carcinomas.     

Hypercalcemia in two cats with squamous cell carcinomas

Hypercalcemia was identified in 2 cats with squamous cell carcinomas. One cat was referred because of multiple cutaneous tumors; the second cat had metastatic disease from an oral squamous cell carcinoma. In both cats, serum immunoreactive midmolecule parathyroid hormone concentration was within the range determined for clinically normal cats. The high serum calcium concentration in these cats may have resulted from the neoplastic disease, as evidenced by the reduction in serum calcium concentration after decrease in tumor size in response to treatment, and by failure to identify other known causes of hypercalcemia.     

A RETROSPECTIVE STUDY ON THE SONOGRAPHIC FINDINGS OF ABDOMINAL CARCINOMATOSIS IN 14 CATS

A retrospective review was performed on 14 cats with histology- or cytology-proven carcinomatosis. The mean age was 12.7 years with a median of 11 years. The diagnosis of carcinomatosis was made by histology in 11 cats and cytology in three cats. Twelve cats had cytologic examination of the peritoneal free fluid and seven cats (58.3%) had evidence of malignant cells. The primary tumor site was determined in 13 cats. The most common organ locations for the primary tumor were the liver (n = 5), pancreas (n = 3), and small intestine (n = 3). Other sites were stomach and spleen in one cat each. Epithelial cell neoplasia was the primary tumor type in 11 cats. Two cats had abdominal lymphomatosis and one cat had abdominal sarcomatosis secondary to metastatic hemangiosarcoma. Free peritoneal fluid and masses in the connecting peritoneum were found in all cats (100%). Additional findings included primary or metastatic masses in abdominal organs in 10 cats (71.4%), lymph node enlargement in five cats (35.7%), pleural effusion in three cats (21.4%), parietal peritoneal masses in two cats (14.3%), and visceral peritoneal masses in one cat (7.1%). Masses in the connecting peritoneal may be a very specific finding for carcinomatosis in cats, especially with a concurrent abdominal neoplastic mass. Parietal and visceral peritoneal masses, while uncommon in this series of cats, have not been reported for other diseases and seem to strongly support a diagnosis of carcinomatosis.     

Tumors involving bone in the domestic cat: a review of fifty-eight cases

This account of 58 spontaneous tumors involving bone in domestic cats compares and contrasts the pathological findings with previous surveys. Of the tumors described, only one was diagnosed as benign. Squamous cell carcinoma was the most common tumor of the series; osteosarcoma was the most common primary tumor. Only two tumors metastasized to the lungs (one hemangiosarcoma and one osteosarcoma), and only three metastasized to a regional node (two squamous cell carcinomas and one lymphosarcoma).     

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

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

PROTON IRRADIATION OF FELINE NASAL PLANUM SQUAMOUS CELL CARCINOMAS USING AN ACCELERATED PROTOCOL

Fifteen cats were treated for squamous cell carcinoma of the nasal planum using proton beam radiation. The protocol used was accelerated with eight equal fractions given on four consecutive days, with a minimum of six hours between fractions. Total dose of radiation delivered was escalated with nine cats receiving 40.4 CGE (60Co Gy equivalent), and three cats each receiving 42.4 and 44.8 CGE. Complete response to the protocol was 60% (9/15), partial response was 33% (5 of 15), and no response was seen in 6.6% (1 of 15). Tumor control rate at one year was 64% and no cat had tumor recurrence after one year. Median survival was 946 days (+/- 516 days). Side effects were minimal with no severe reactions noted in the early or late period. This protocol offers an effective treatment for squamous cell carcinoma of the feline nasal planum with minimal side effects and may be adaptable to conventional radiation sources particularly when the field size is very small.     

Immunohistochemical analysis of cyclin A, cyclin D1 and P53 in mammary tumors, squamous cell carcinomas and basal cell tumors of dogs and cats

The involvement of cyclin A, cyclin D1 and p53 proteins in canine and feline tumorigenesis was analyzed immunohistochemically. In the present study, a total of 176 cases were examined, among which there were 108 canine cases (75 mammary lesions, 16 squamous cell carcinomas and 17 basal cell tumors) and 68 feline cases (43 mammary lesions, 20 squamous cell carcinomas and 5 basal cell tumors). Speckled nuclear staining for cyclin A was observed in 19/38 (50%) canine malignant mammary tumors and 18/37 (48.6%) feline mammary carcinomas, while this was not seen in benign mammary tumors of either dogs or cats. Marked intense nuclear cyclin A staining was seen in 7/16 (43.8%) canine squamous cell carcinomas and 18/20 (90.0%) feline squamous cell carcinomas. Only 3/17 (17.6%) canine basal cell tumors showed slight and scattered staining for cyclin A. Expression of cyclin D1 was very rare in both canine and feline tumors. Nuclear staining of p53 was found in 7/37 (18.9%) feline mammary carcinomas. Intense immunoreactivity for p53 was found in 6/16 (37.5%) canine squamous cell carcinomas and 8/20 (40%) feline squamous cell carcinomas. These results suggest that cyclin A may have a role in the proliferation of canine malignant mammary tumors, feline mammary carcinomas and squamous cell carcinomas of dogs and cats, and p53 may associate with the tumorigenesis of feline mammary carcinomas and squamous cell carcinomas of dogs and cats.     

Hepatobiliary neuroendocrine carcinoma in cats: a clinicopathologic, immunohistochemical, and ultrastructural study of 17 cases

Hepatobiliary neuroendocrine carcinoma was diagnosed in 17 cats in a period of 10 years. Seven tumors were of intrahepatic origin, one of which was a composite containing components of epithelial and neuroendocrine carcinoma. Nine tumors were of extrahepatic origin, and one tumor was located in the gall-bladder. The cats were adult and geriatric, and the male : female ratio varied according to tumor group. Hepatomegaly, anorexia, weight loss, and vomiting were the most common clinical signs observed in the cats with hepatic neuroendocrine carcinoma. The cats with extrahepatic neuroendocrine carcinoma showed these signs plus icterus (5/9) and high concentrations of hepatic enzymes. Histologically, the hepatic neuroendocrine carcinomas had two patterns, one with acinar structures separated by vascular stroma lined by cuboidal or columnar cells and the other solid with groups of anaplastic cells separated by vascular stroma. The composite tumor consisted of both bile duct carcinoma and neuroendocrine carcinoma. The extrahepatic neuroendocrine carcinomas and the gallbladder neuroendocrine carcinoma were characterized by solid sheets or groups of round to oval cells with vascular or fibrovascular stroma. Immunohistochemical examination of 10 of the neuroendocrine carcinomas revealed that all 10 stained with neuron-specific enolase; one bile duct carcinoma and the gallbladder carcinoma stained with chromogranin; four of five bile duct carcinomas and the gall bladder carcinoma stained with synaptophysin; and one bile duct carcinoma stained with gastrin. One cat with hepatic carcinoma had duodenal ulcer; in this cat, ultrastructural studies showed neurosecretory granules leading to the diagnosis of Zollinger-Ellison syndrome. In four cats in which necropsy was permitted, carcinomatosis (4/4), lymph nodes (4/4), lungs (2/4), and intestines (1/4) were the metastatic sites. Fourteen of the 17 cats were euthanatized during or immediately after surgery.     

IMAGING FINDINGS IN PANCREATIC NEOPLASIA AND NODULAR HYPERPLASIA IN 19 CATS

Pancreatic neoplasia in cats is rare and associated with a poor prognosis, but pancreatic nodular hyperplasia is a common incidental finding. The purpose of this study was to describe radiographic and ultrasonographic findings in cats with pancreatic neoplasia or nodular hyperplasia. Fourteen cats (age 3-18 years) were diagnosed with malignant pancreatic tumors: carcinoma/adenocarcinoma (n = 11), lymphoma (n = 1), squamous cell carcinoma (n = 1), and lymphangiosarcoma (n = 1). The most common radiographic findings were an abdominal mass or mass effect (6/6) and lack of serosal margin detail (4/6). On ultrasound, the most common finding was a focal pancreatic mass or nodule, with a size range from 0.4 cm to more than 7.0 cm (8/14). Lymphadenopathy (7/14) and abdominal effusion (7/14) were frequently seen. Five cats (age 10-16 years) with adenomatous/nodular hyperplasia had an abdominal mass or mass effect as the most common radiographic finding (3/3). On ultrasound, all cats had multiple hypoechoic nodules between 0.3 and 1.0 cm associated with the pancreas. Other common findings were pancreatic thickening (2/5), lymphadenopathy (2/5), and abdominal effusion (2/5). The only imaging finding unique to malignant pancreatic tumors was the presence of a single pancreatic nodule or mass exceeding 2cm in at least one dimension (4/14). Although there was a tendency for neoplastic lesions to manifest as single larger lesions and for nodular hyperplasia to manifest as multiple smaller lesions, there was overlap of the imaging findings in both entities. Radiographs and ultrasound can complement but not replace cytology and histopathology in the diagnosis of feline pancreatic neoplasia.     

THE RADIOGRAPHIC APPEARANCE OF PRIMARY LIVER NEOPLASIA IN DOGS

The signalment, anamnesis, and histopathologic, gross pathologic, and radiographic findings in 22 dogs with nonvascular, nonhematopoletic primary liver tumors were reviewed. The tumor types represented were hepatoma (8), bile duct cystadenoma (1), hepatocellular carcinoma (5), and cholangiocellular carcinoma (8). The dogs averaged 11.1 years of age. Females were predisposed to cholangiocellular carcinoma. The most common presenting clinical signs were general malaise, anorexia, PU/PD, vomiting, and seizures. Tumors ranged in size from diffuse 0.5-1 cm nodules to an 18-cm solitary mass and were located in any of the liver lobes. Four of the five diffuse tumors were cholangiocellular carcinomas. The most common radiographic appearance for any type of liver tumor was a right cranial abdominal mass causing caudal and left gastric displacement. In 54.5% of the dogs, radiographic evidence of intraperitoneal disease was identified. Nodular interstitial pulmonary masses were seen in 3 of the 22 dogs.     

RADIOGRAPHIC APPEARANCE OF BRONCHOALVEOLAR CARCINOMA IN NINE CATS

Thoracic radiographs of nine cats with confirmed bronchoalveolar carcinoma (BAC) were reviewed retrospectively. Radiographic appearance of BAC was divided into three categories: mixed bronchoalveolar pattern, ill-defined alveolar mass, or mass with cavitation. In addition to these radiographic signs, all nine cats had evidence of some form of bronchial disease. Cavitary lesions were the most common finding (n = 5). In addition, three cats in this category had diffuse bronchointerstitial opacity and one cat had focal peribronchial cuffing. Five cats had either a mixed bronchoalveolar pattern with bronchiectasis (n = 3) or an ill-defined alveolar mass with peribronchial cuffing (n = 2). One cat had both a mixed bronchoalveolar pattern and a cavitary mass. Each of these nine cats had some form of bronchial disease (bronchointerstitial pattern, peribronchial cuffing, or bronchiectasis), which aids in the radiographic diagnosis of bronchoalveolar carcinoma and may represent airway metastasis.     

NODULAR FAT NECROSIS IN THE FELINE AND CANINE ABDOMEN

The radiographic appearance of nodular fat necrosis is described in ten cats and one dog. The most common radiographic sign was the presence of a focal mineralized circular to oval soft tissue mass in the abdominal fat as present in 9 cats. These masses had a distinct eggshell-like rim encapsulating the lesion. In one cat and one dog multiple masses were present, without radiographic signs of mineralization. Abdominal ultrasound was performed in three cats and one dog, findings included the presence of hyperechoic masses with associated acoustic shadowing, some with a hypoechoic centre. Almost all animals were old and obese. In three cats and one dog, changes were confirmed with biopsy or post mortem examination. Lesions having the appearance of those in this paper are most likely incidental findings and should not be confused with abdominal masses of neoplastic origin. Ultrasound can be helpful in identifying such lesions.     

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.