Gastrict carcinoma with pseudohyperparathyroidism in a horse

Pseudohyperparathyroidism was diagnosed in a mature stallion presented for anorexia, weight loss, pollakiuria and constipation. Laboratory findings included hypercalcemia, hypophosphatemia, anemia and isosthenuria. Thoracocentesis indicated an exfoliating squamous cell carcinoma. At necropsy, a squamous cell carcinoma of the stomach with metastases to the abdominal and thoracic cavities was diagnosed. No osseous metastases were found. No gross or microscopic renal lesions were noted. Bone tissue showed arrested resorption, and the parathyroid gland was atrophic.     

The epidemiology of squamous cell carcinoma of the perineal region of sheep: Abattoir and flock studies

The roles of age, tail length and the Mules operation in the epidemiology of squamous cell carcinoma in ewes were studied. The prevalence of the disease in adult sheep slaughtered at 2 abattoirs was 0.08%. No cases occurred in lambs. Of all adult sheep condemnations before slaughter, 38.5% were due to squamous cell carcinoma. Of these sheep, 73.3% had a single lesion of the vulva (62.9%), tail (6.6%), or anus (3.8%), while 26.7% had lesions at more than one site. The number of lesions was significantly greater (p < 0.01) in sheep with a radical Mules operation than in those with a modified Mules operation or not mulesed. Tails were significantly shorter (p < 0.01) in affected than unaffected sheep. Small keratinised outgrowths on the skin of the tail and perineum were considered on histological grounds to be precursors of squamous cell carcinomas. On one affected farm 4% of ewes were culled in one year for gross lesions of squamous cell carcinomas. A further 3.5% of sheep with gross lesions and 25.3% with precursor lesions remained in the flock, undetected by the farmer. Gross lesions were not observed in ewes under 3 years of age, whereas precursors occurred in all age groups, including one-year-old ewes. The prevalence of lesions increased with age, from 0.43% in 5-year-old ewes to 5.14% in 6-year-old and 41% in 7-year-old ewes. Discriminant analysis indicated that age of ewe, tail length and the width of the healed Mules operation were important determinants of squamous cell carcinoma. In all the sheep studied the style of mulesing was consistently radical, with a mean healed width of 12.3 ± 2.6 cm. Tails were amputated much shorter than the traditionally recommended length of level with the tip of the vulva. The presence of gross and precursor lesions was associated with shorter tails and a radical Mules operation. It is suggested that the prevalence of the disease may be reduced by the adoption of a less severe mulesing technique and leaving tails longer.     

Endocrine Causes of Calcium Disorders

Endocrine diseases that may cause hypercalcemia and hypocalcemia include hyperparathyroidism, hypoparathyroidism, thyroid disorders, hyperadrenocorticism, hypoadrenocorticism, and less commonly pheochromocytoma and multiple endocrine neoplasias. The differential diagnosis of hypercalcemia may include malignancy (lymphoma, anal sac carcinoma, and squamous cell carcinoma), hyperparathyroidism, vitamin D intoxication, chronic renal disease, hypoadrenocorticism, granulomatous disorders, osteolysis, or spurious causes. Hypocalcemia may be caused by puerperal tetany, pancreatitis, intestinal malabsorption, ethlyene glycol intoxication, acute renal failure, hypopararthyroidism, hypovitaminosis D, hypomagnesemia, and low albumin. This article focuses on the endocrine causes of calcium imbalance and provides diagnostic and therapeutic guidelines for identifying the cause of hypercalcemia and hypocalcemia in veterinary patients.     

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.     

Hypercalcemia in cats: a retrospective study of 71 cases (1991-1997)

A retrospective study was conducted to characterize the diseases, clinical findings, and clinicopathologic and ultrasonographic findings associated with hypercalcemia (serum calcium concentration >11 mg/dL) in 71 cats presented to North Carolina State University Veterinary Teaching Hospital. The 3 most common diagnoses were neoplasia (n = 21), renal failure (n = 18), and urolithiasis (n = 11). Primary hyperparathyroidism was diagnosed in 4 cats. Lymphoma and squamous cell carcinoma were the most frequently diagnosed tumors. Calcium oxalate uroliths were diagnosed in 8 of 11 cats with urolithiasis. Cats with neoplasia had a higher serum calcium concentration (13.5 ± 2.5 mg/dL) than cats with renal failure or urolithiasis and renal failure (11.5 ± 0.4 mg/dL; P <.03). Serum phosphorus concentration was higher in cats with renal failure than in cats with neoplasia ( P < .004). Despite the fact that the majority of cats with uroliths were azotemic, their serum urea nitrogen and creatinine concentrations and urine specific gravity differed from that of cats with renal failure. Additional studies are warranted to determine the underlying disease mechanism in the cats we identified with hypercalcemia and urolithiasis. We also identified a small number of cats with diseases that are not commonly reported with hypercalcemia. Further studies are needed to determine whether an association exists between these diseases and hypercalcemia, as well as to characterize the underlying pathophysiologic mechanism for each disease process.     

Superficial keratectomy and topical mitomycin C as therapy for a corneal squamous cell carcinoma in a dog

A 10-year-old female West Highland white terrier was presented with refractory hyperplastic keratitis of the left cornea of one month's duration. At this time, a vascularised and rough lesion 5 mm in diameter was observed on the left cornea. No other abnormality was recognised on the affected eye. The corneal neoplasm was surgically removed and histologically diagnosed as a squamous cell carcinoma. For two months after the surgery, 0.04 percent mitomycin C (MMC) eye drops were applied as adjuvant chemotherapy. Primary corneal squamous cell carcinoma with no history of keratoconjunctivitis sicca is rare in dogs. In the present report, surgical removal of the neoplasm was combined with the topical administration of the anticancer drug mitomycin C and a good prognosis was obtained. The result indicates that the combination treatment used in this case may be an appropriate therapeutic choice for corneal squamous cell carcinoma in dogs.     

Survey of equine cutaneous neoplasia in the Pacific Northwest.

A retrospective study examined data regarding equine cutaneous and mucocutaneous neoplasms submitted to the Veterinary Diagnostic Laboratory at Oregon State University in a 3.5-year period. A total of 536 neoplasms were identified, accounting for 30% of the total equine pathology submissions. Sarcoid, squamous cell carcinoma, melanocytic tumors, papillomas, and mast cell tumors were the most common neoplasms, constituting 87.5% of all cutaneous neoplasms. Sarcoids represented 51.4% of all neoplasms and 15.18% of total equine accessions. Sarcoid was most common in paints, quarter horses, and Arabians, and was the only common tumor in donkeys and mules. Mean age at diagnosis of equine sarcoid was 9 years. Squamous cell carcinoma constituted 18.3% of all neoplasms and 5.41% of total equine accessions. Ocular squamous cell carcinoma was most common in paints and quarter horses, and penile/preputial squamous cell carcinoma was most common in appaloosas and quarter horses. The mean age of horses with ocular squamous cell carcinoma (13 years) and squamous cell carcinoma of the skin (15 years) was significantly less (P < 0.5) than that of horses with squamous cell carcinoma of the penis and prepuce (21 years) or vulva, anal, and perianal skin (19 years). Findings suggest that equine sarcoid and squamous cell carcinoma occur more frequently in the Pacific Northwest than in the northeastern United States.     

THE EPIDEMIOLOGY OF SQUAMOUS CELL CARCINOMA OF THE PERINEAL REGION OF SHEEP

SUMMARY A high prevalence of squamous cell carcinoma of the perineal region of ewes was detected in the wheat belt area of Western Australia. A postal survey of 80 farms was conducted in the area, seeking information on the epidemiology of the condition, based on the farmers identification of the disease. Eighty-two per cent of flocks surveyed were affected, the mean prevalence in ewes of all ages being 2.29% (range 0.12% to 4.0%). The prevalence increased with age, from 0.05% in 1- to 2-year-old ewes to 3.09% in ewes over 5 years of age. The prevalence in the population of 121,605 ewes on all farms (affected and unaffected) surveyed, was 0.93%. The majority of lesions (88.9%) involved the vulva. The tail was affected in 23.8% of cases and the perineum in 12.8%. Affected ewes were usually destroyed and were a direct financial loss. Only 2 farmers reported the condition in rams, and 5 in wethers. Causal factors were not identified, although the radical Mules operation, time of shearing, and solar radiation were implicated.     

Corneal squamous cell carcinoma in a Border Collie

A 6-year-old, female, spayed Border Collie was presented to the Unit of Comparative Ophthalmology at the Animal Health Trust with a 6-month history of a progressive nonpainful opacity of the left cornea. A keratectomy was performed and the tissue submitted for histopathology. The diagnosis was squamous cell carcinoma. There has been no recurrence of the neoplasm to date (5 months). Canine corneal squamous cell carcinoma (SCC) has not been reported previously in the UK.     

Paraneoplastic Hypercalcemia

Paraneoplastic syndromes (PNSs) are neoplasm-associated alterations in bodily structure or function or both that occur distant to the tumor. They are an extremely diverse group of clinical aberrations that are associated with the noninvasive actions of the tumor. In many situations, the PNS parallels the underlying malignancy, and therefore, successful treatment of the tumor leads to disappearance of the PNS. Alternatively, recurrence of the PNS after successful treatment signals recurrence of the tumor, and the return of the PNS often significantly precedes the detectable recurrence of the tumor. This is often the case with paraneoplastic hypercalcemia, often referred to as hypercalcemia of malignancy (HM). The most common cause of hypercalcemia in dogs is cancer. Neoplasia is diagnosed in approximately two-thirds of dogs with hypercalcemia vs. approximately one-third in cats. A variety of tumors have been associated with HM. Lymphoma is the most common cause of HM, and the most common anatomical site for dogs with lymphoma-associated HM is the cranial mediastinum. Other tumors associated with HM in dogs and cats include anal sac apocrine gland adenocarcinoma, thyroid carcinoma, multiple myeloma, bone tumors, thymoma, squamous cell carcinoma, mammary gland carcinoma/adenocarcinoma, melanoma, primary lung tumors, chronic lymphocytic leukemia, renal angiomyxoma, and parathyroid gland tumors. As HM is a potential medical emergency, the primary goal in cases of HM is the elucidation of the underlying cause and thereby instituting the appropriate specific therapy.     

Hypercalcemia and parathyroid hormone‐related peptide expression in a dog with thyroid carcinoma and histiocytic sarcoma

A 9.5‐year‐old, male castrated Walker Hound was presented for evaluation of progressive weakness, anorexia, and weight loss. Imaging revealed multiple abdominal and thoracic masses and ascites; fine‐needle aspirates of mesenteric and splenic masses confirmed malignancy, most likely histiocytic sarcoma. Laboratory analyses revealed increased ionized calcium and parathyroid hormone‐related peptide (PTH‐rP) concentrations, and concurrent low–normal parathyroid hormone concentration, consistent with humoral hypercalcemia of malignancy. Necropsy was performed after euthanasia. The dog had disseminated histiocytic sarcoma, including sarcomatosis, as well as bilateral thyroid carcinoma. PTH‐rP immunostaining was positive in the thyroid carcinoma but negative in the histiocytic neoplasm. These results suggest that thyroid carcinoma‐associated hypercalcemia can be caused by tumor secretion of PTH‐rP.     

Intracranial squamous cell carcinoma in a cow

An exophthalmic right eye was surgically removed from a nine year old Holstein cow. Subsequent post mortem examination revealed a large intracranial mass at the base of the brain which was diagnosed as a squamous cell carcinoma. The orbital and sphenoid bones were intact and it is believed that the neoplasm entered the cranial cavity from the orbit via the foramen orbitorotundum. Both intracranial squamous cell carcinoma and extension of orbital neoplasia through foramina are rare.     

SQUAMOUS-CELL CARCINOMA OF THE VULVA IN MERINO SHEEP

Squamous-cell carcinoma of the vulva was observed in 3.1% of Merino ewes up to 3 years old. It is suggested that this high incidence of tumours was related to increased exposure of the perineal region to direct sunlight. It occurred in a group of sheep where short docking of tails and a radical surgical procedure to reduce cutaneous myiasis (Mules' operation) both led to greater exposure of the perineal region. The perineum was also subject to scarring from the operation and to application of organophosphate compounds to control cutaneous myiasis.     

Squamous cell carcinoma of the reticulum and liver in a Simmental cow

This report describes an 8.8-year-old Simmental cow with squamous cell carcinoma of the reticulum and liver. The cow had calved recently and was referred to our clinic because of intractable fever, anorexia and progressive indigestion. The general condition and mental status were moderately affected and rectal temperature and respiratory rate were significantly elevated. There were no ruminal sounds and pinching of the withers consistently elicited a grunt. Serum activities of gamma glutamyl transferase, glutamate dehydrogenase and sorbitol dehydrogenase were elevated. Radiographic examination of the reticulum and ultrasonographic examination of the reticulum, liver and abdominal cavity revealed multifocal, poorly demarcated, heterogeneous and echogenic changes in the liver. Biopsy of these lesions yielded a diagnosis of squamous cell carcinoma. The cow was euthanized and a postmortem examination confirmed the diagnosis. A 15 by 15 cm neoplasm was found in the reticular wall, and histological examination showed squamous cell carcinoma. It was assumed that the reticular mass was the primary tumour, which metastasized to the liver via the portal vein.     

Comparison of growth and differentiation of normal and neoplastic canine keratinocyte cultures

Neoplastic canine keratinocytes derived from a spontaneous oral squamous cell carcinoma were maintained in culture for more than 45 passages. The presence of desmosomes and keratin filaments was demonstrated by electron microscopy and immunohistochemistry. The keratinocytes were grown in two different culture conditions to induce variations in the stage of differentiation, i.e., in submerged cultures and at the air-liquid interface. For comparison, normal canine keratinocytes were grown under the same conditions. Anisocytosis was present in neoplastic cultures grown submerged in medium. Grown at the air-liquid interface, neoplastic keratinocytes differentiated into a well-organized, multilayered stratified squamous epithelium analogous to normal keratinocytes. Rare areas of irregular growth and formation of whorls were detected. Expression of lectin binding sites and specific cell surface antigens of neoplastic and normal keratinocytes demonstrated marked similarities between the two cell lines. Neoplastic cells lacked certain surface antigens that are present on normal cells. Squamous cell carcinoma cells grew faster than normal canine keratinocytes as demonstrated by growth curve evaluation. Neoplastic keratinocytes responded to growth stimulation by epidermal growth factor and cholera toxin as do normal keratinocytes. Neoplastic cells grown in medium lacking these factors proliferated faster than growth factor stimulated normal keratinocytes.     

Squamous cell carcinoma of the tongue of the cat

A case of squamous cell carcinoma of the tongue in an 11-year-old castrated male cat is described. The clinical signs of excessive salivation and inability to eat or drink were associated with enlargement of the tongue. The pathology, possible aetiology and pathogenesis of the neoplasm are discussed.     

Extensive caudal vena cava thrombosis secondary to unilateral renal tubular cell carcinoma in a dog

A nine-year-old German shorthaired pointer cross was admitted because of partial anorexia, exercise intolerance and haematuria. On clinical examination, subcutaneous oedema, purpura and ascites were detected along with a palpable mass in the right craniodorsal abdomen. Laboratory findings included regenerative anaemia, leucocytosis, thrombocytopenia, azotaemia, increased blood serum alkaline phosphatase and proteinuria. Radiographic and ultrasonographic examinations revealed a large neoplasm involving the right kidney. Computed tomography further showed that the neoplastic tissue had spread into the lymph nodes, the wall of the caudal vena cava, the liver and lungs. The right renal vein, caudal vena cava and iliac veins appeared enlarged and secondarily thrombosed. A diagnosis was made of renal tubular cell carcinoma with secondary venous thrombosis. Gross postmortem examination confirmed the imaging findings, while light and electron microscopic examination revealed that the neoplasm was a solid carcinoma originating from the proximal convoluted renal tubules.     

Esophageal adenosquamous carcinoma in a cat

Esophageal carcinoma was observed in an eight-year-old, castrated male, Japanese domestic cat. Histologically, this neoplasm consisted of two different growth patterns, squamous cell carcinoma and adenocarcinoma. The results of immunohistochemical examination supported the fact that the two kinds of neoplastic cells have different characteristics. The tumor was, therefore, diagnosed as adenosquamous carcinoma. Esophageal tumors in the cat are very rare and, if any, neither adenocarcinoma nor adenosquamous carcinoma has been reported up to the present.