Squamous cell carcinoma of the vulva in a cow

An 8-year-old Holstein cow was evaluated because of a slowly enlarging vulvar mass that had impaired artificial insemination attempts. Vulvar squamous cell carcinoma was diagnosed. Clinical cases of vulvar squamous cell carcinoma have not been as widely reported as those of ocular squamous cell carcinoma in cattle. Treatment modalities for vulvar squamous cell carcinoma have not been as thoroughly investigated as for those of the ocular condition. Cryosurgery and radio-frequency hyperthermia appear to be the optimal therapeutic modalities, each providing up to 90% tumor remission.     

Squamous cell carcinoma in a tuatara (Sphenodon punctatus)

CASE HISTORY: A mature male tuatara was presented with a history of recurrent cloacal prolapse. CLINICAL AND PATHOLOGICAL FINDINGS: The prolapsed tissue included a 12 mm diameter mass, which histologically showed cords and nodules of neoplastic epithelial cells. DIAGNOSIS: The mass was diagnosed as a squamous cell carcinoma with ulceration of the overlying stratified squamous epithelium and diffuse inflammation of the surrounding dermis. CLINICAL RELEVANCE: This case presented a rare opportunity to investigate squamous cell carcinoma in a long-lived lower vertebrate species. Future recurrence or metastasis of the mass may add useful information to the current base of knowledge of the behaviour of malignant neoplasms in reptiles.     

Squamous cell carcinoma in a tuatara (Sphenodon punctatus)

CASE HISTORY: A mature male tuatara was presented with a history of recurrent cloacal prolapse.

CLINICAL AND PATHOLOGICAL FINDINGS: The prolapsed tissue included a 12 mm diameter mass, which histologically showed cords and nodules of neoplastic epithelial cells.

DIAGNOSIS: The mass was diagnosed as a squamous cell carcinoma with ulceration of the overlying stratified squamous epithelium and diffuse inflammation of the surrounding dermis.

CLINICAL RELEVANCE: This case presented a rare opportunity to investigate squamous cell carcinoma in a long-lived lower vertebrate species. Future recurrence or metastasis of the mass may add useful information to the current base of knowledge of the behaviour of malignant neoplasms in reptiles.     

Oesophageal obstruction in an aged pony associated with squamous cell carcinoma

An aged miniature pony was referred for chronic recurrent oesophageal obstruction. Endoscopic examination demonstrated distal oesophageal constriction and radiography confirmed an irregular soft tissue mass in the region of the distal intrathoracic oesophagus. The pony was subjected to euthanasia and post mortem examination confirmed squamous cell carcinoma of the distal oesophagus and stomach. Oesophageal squamous cell carcinoma is a rare condition in horses, but should be considered as a differential diagnosis in cases of chronic recurrent obstruction, particularly in older horses.     

Topical 5-fluorouracil as an adjunct treatment in equine corneolimbal squamous cell carcinoma

An 11-year-old crossbreed mare was presented with a nodular, pink mass at the temporal corneolimbal junction of the right eye. Histopathology confirmed the diagnosis of invasive squamous cell carcinoma. The mare underwent lamellar keratectomy and conjunctivectomy under general anaesthesia, followed by adjunctive topical chemotherapy with 1% 5-fluorouracil solution for 10 days post-operatively. Adverse effects included moderate conjunctival inflammation and exuberant granulation tissue formation at the surgical site, responding to surgical debulking and topical corticosteroid application. No mass regrowth was present at 12 months following discharge. This report describes the successful use of topical 1% 5-FU as an adjunctive treatment for equine ocular squamous cell carcinoma.     

Spontaneous necrotizing sialometaplasia of the submandibular salivary gland in a Beagle dog

A single mass was found on the left submandibular salivary gland at necropsy of a 15-month-old male commercially bred laboratory Beagle dog from a control dose group from a repeat toxicity study. Microscopically, the mass was composed of a well-demarcated area of coagulative necrosis surrounded and separated from the normal salivary gland tissue by a thick fibrovascular capsule. Necrosis was admixed with areas of hemorrhage, fibrin, edema, fibrinoid necrosis of the vascular tunica media, and thrombosis of small and large vessels. Within the necrotic tissue, there was marked ductal hyperplasia, and squamous metaplasia of duct and acinar epithelium. The mass was diagnosed as necrotizing sialometaplasia of the submandibular gland. Hyperplastic ductal elements and squamous metaplasia can be mistaken microscopically with squamous cell carcinoma. Therefore, pathologists should be aware of this lesion as to avoid errors in the diagnosis of this benign pathologic condition.     

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.     

Feline papillomavirus infection in a cat with Bowen-like disease and cutaneous squamous cell carcinoma

A cutaneous mass in the neck was excised in a 13-year-old cat. Histopathological examination of the resected tissue revealed a multicentric squamous cell carcinoma in situ resembling Bowen's disease of man. The tumor showed a multifocal transformation to an infiltrative squamous cell carcinoma. Histological and immunohistological findings excluded actinic keratosis and feline viral plaques and allowed a classification as an irregular non-hyperkeratotic type of multicentric squamous cell carcinoma in situ. As a possible causative agent feline papillomavirus type 2 was detected using nested PCR in formalin-fixed material.     

Radioactive gold-198 seeds for the treatment of squamous cell carcinoma in the eyelid of a cat

A 19-year-old, speyed, domestic short-hair cat was presented with an eyelid tumour of 3 months duration. Ophthalmic examination revealed a large, raised, ulcerated and bleeding mass affecting the left lower eyelid. The mass was 12 mm x 10 mm in size, extended to the medial canthus and had eroded 10 mm of eyelid margin. Mandibular lymph nodes were not palpably enlarged. A diagnosis of squamous cell carcinoma was confirmed by histologic examination. Due to involvement of more than half the lower eyelid, it was decided that treatment with radioactive gold-198 seeds was appropriate. Nine radioactive gold-198 seeds were implanted, delivering a minimum tumour dose of 65 Gy. Three weeks postoperatively the mass had resolved, with only a small scab remaining. After a further 3 weeks, there was no evidence of the eyelid tumour. Although approximately 7 mm of eyelid margin was absent, this did not cause any clinical signs other than mild conjunctivitis. There was no evidence of the tumour 10 months postoperatively, when the cat was euthanased for unrelated disease.     

Carcinoma in the urinary bladder of a cat: cytologic findings and a review of the literature

Percutaneous fine needle aspiration biopsy (FNAB) was used to diagnose a urinary bladder carcinoma in an aged cat. The cytologic appearance of specimens collected initially was similar to that reported for canine transitional cell carcinoma. However, impression smears of the tumor made at necropsy 7 weeks later consisted predominantly of atypical squamous epithelial cells compatible with squamous cell carcinoma. Histologically, the malignancy was noted to have intermixed areas of abnormal squamous and transitional cell proliferation. The neoplasia was interpreted as a transitional cell carcinoma with extensive transformation to squamous cell carcinoma. This report examines the use and limitations of FNAB in the diagnosis of feline urinary bladder carcinoma and the incidence and behavior of these tumors in the cat.     

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.     

Spontaneous Adenosquamous Carcinoma with Rapid Growth and EMT-like Changes in the Mammary Gland of a Young Adult Female BALB/c Mouse

This study histopathologically and immunohistochemically investigated a spontaneously occurring single mass subcutaneously located in the left lower abdomen of a female BALB/cAJcl−nu/+ mouse at 10 weeks of age. The mass was about 20 × 15 × 10 mm in size after formalin fixation; nevertheless, it was not detected by clinical observations at 9 weeks of age. H&E staining revealed the tumor origin was epithelial and probably arose from the mammary gland, and the tumor cells demonstrated a squamous, acinar or polyhedral/basal pattern. A cell kinetics analysis revealed that many of the tumor cells of the squamous, acinar or polyhedral/basal component were positive for PCNA and cyclin D1, although there were a few of TUNEL-positive tumor cells in all of the components. An epithelial/mesenchymal analysis demonstrated that most of the tumor cells of the squamous and acinar components contained keratin and E-cadherin; however, most of the tumor cells of the polyhedral/basal component were less or very weakly positive for these markers. The tumor cells of the squamous component were negative for vimentin and SMA; however, many of the tumor cells of the polyhedral/basal component exhibited vimentin. In addition, expression of SMA was confirmed in some tumor cells of the acinar and basal components. Based on the microscopic and immunohistochemical characterizations, the tumor was diagnosed to be adenosquamous carcinoma that originated from the mammary gland with rapid growth, and the tumor cells demonstrated epithelial-mesenchymal transition-like changes.     

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.     

Oral squamous cell carcinoma in a coyote (Canis latrans).

A 19-yr-old spayed female coyote (Canis latrans) was evaluated for an elliptical swelling of the skin beneath its right eye and an elevated mass that involved the soft and hard palate and gingivae around the upper right carnassial tooth and molars. Histopathologic analysis revealed a squamous cell carcinoma, and a postmortem examination revealed no evidence of vascular invasion or dissemination to the regional lymph nodes or viscera. This report describes the biology and progresion of an oral squamous cell carcinoma in an aged captive coyote.     

Long-term outcome of treatment of a squamous cell carcinoma of the foot by amputation of the distal limb in a pony

This report describes a rare case of squamous cell carcinoma (SCC) in a 10-year-old Shetland pony. The pony was presented for evaluation of a chronic, ulcerating mass of the foot associated with a nonweightbearing lameness of the right forelimb. Foot radiographs revealed an aggressive bone lesion with severe osteolysis of the distal phalanx. Amputation of the digit was performed under general anaesthesia at the level of the metacarpophalangeal joint using a palmar flap technique and a transfixation cast for protection of the stump. Avascular necrosis, infection and dehiscence of the stump occurred 3 weeks later and a second amputation was performed at the level of the proximal third of the third metacarpal bone. Histopathology revealed a squamous cell carcinoma. After healing of the stump, a prosthesis was fitted to the limb for improved ambulation of the pony. Two years after the amputation, telephone follow-up with the referring veterinarian and the owner, revealed that the pony was healthy and able to go out daily in a paddock with its prosthesis. SCC represents an unusual indication for limb amputation. Successful outcome is rarely reported in horses.     

Squamous cell carcinoma with sarcomatous stroma in the nasal cavity of a dog

This is a report of an unusual squamous cell carcinoma in the nasal cavity of a dog. A 13-year-old Golden Retriever was presented with a unilateral nasal and ocular discharge. Although a nasal tumour was suspected, initial diagnostic investigations were unrewarding, and, with worsening clinical signs, the dog was euthanatized. Necropsy examination confirmed the presence of a nasal tumour that was composed histologically of both a well-differentiated squamous cell carcinoma component blending with a predominant spindle cell component. Immunohistochemical staining with anti-human keratin/cytokeratin (AE1/AE3, CAM 5.2 and broad spectrum cytokeratin), Vimentin, Desmin, smooth muscle actin and S-100 protein supported a diagnosis of a squamous cell carcinoma with (pseudo) sarcomatous stroma.     

Successful treatment of a squamous cell carcinoma in a white rhinoceros, Ceratotherium simum

A captive 33-year-old male white rhinoceros with seasonal dermatitis was diagnosed with a malignant squamous cell carcinoma on the right flank. Staphylococcus aureus was cultured from the skin lesions. No fungal or yeast was isolated. The dermatitis was treated with a combination of oral antibiotics (trimethoprim-sulphadiazine) and topically with weekly chlorhexidine washes and a mixture of a zinc oxide, balsam peru and bismuth oxide cream. Under azaperone and butorphanol anaesthesia, the skin tumour was surgically removed. The tumour was excised with wide margins and allowed to heal by secondary intention as primary wound closure was not possible. A post-mortem performed 2 years later for an unrelated condition revealed no metastases or recurrence of the skin tumour. It was presumed that chronic irritation or trauma may have contributed to the development of the skin tumour. This is the first detailed report of the successful treatment of a squamous cell carcinoma not associated with the horn in a rhinoceros.     

Oral and peripheral vestibular signs in a cat with squamous cell carcinoma

A 13-year-old female, spayed cat had oral and vestibular signs resulting from a 3-cm mass extending from the tympanic membrane to the nasopharynx. Radiography revealed a soft-tissue density in the tympanic bulla. Cytologic examination and biopsy confirmed the presence of a squamous cell carcinoma. Squamous cell carcinoma causes vestibular signs in the cat. In this cat, squamous cell carcinoma, involving the middle and inner ear, resulted in oral and vestibular signs.