Squamous cell carcinoma of the anal sac in five dogs.
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Tumors of the perianal area of dogs are common and include multiple tumor types. Whereas perianal adenomas occur often, adenocarcinomas of the apocrine glands of the anal sac occur less frequently. A review of the literature revealed no reports of squamous cell carcinomas arising from the epithelial lining of the anal sac. Squamous cell carcinomas originating from the lining of the anal sac were diagnosed in five dogs. Microscopically, the tumors consisted of variably sized invasive nests and cords of epithelial cells displaying squamous differentiation. Four of the five dogs were euthanatized because of problems associated with local infiltration by the tumors. In the fifth dog, there was no evidence of tumor 7 months after surgical removal, but further follow up was not available. (+info)
Metastatic anal sac adenocarcinoma in a dog presenting for acute paralysis.
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A 4-year old, female spayed terrier was referred for hind end paresis that rapidly progressed to paralysis. Spinal radiographs revealed vertebral collapse and bony lysis. Myelography confirmed spinal cord compression and surgical exploration found an extradural soft tissue mass. Metastatic anal sac adenocarcinoma was diagnosed at postmortem examination. (+info)
Effective treatment of perianal tumors in dogs with electrochemotherapy.
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BACKGROUND: Electrochemotherapy is an antitumor therapy that utilizes locally-delivered, short intense direct current electric pulse to the tumor nodule plus chemotherapy. The aim of the present study was to evaluate the electrochemotherapy treatment of perianal tumors of different sizes in dogs. MATERIALS AND METHODS: In 12 dogs, 26 tumor nodules of perianal tumors of different size, and clinically expected to be of different histological type, were treated with electrochemotherapy. Electrochemotherapy consisted of intratumoral injection of cisplatin (1 mg/cm3) or bleomycin (3 mg/cm3), followed by application of electric pulses (8 electric pulses; amplitude, 910 V, duration, 100 micros, frequency, 1 Hz) to the tumor nodule. RESULTS: Responses to treatment were assessed 4 weeks after the therapy; 82% of all tumors treated with electrochemotherapy responded with objective response (OR) (complete response (CR)=41%, partial response (PR)=41%), 16% responded with no change (NC) and 1 tumor (2%) went to progressive disease (PD). At the end of the observation period for each tumor, ranging from 1 to 34 months, 92% OR (CR=65%, PR=27%), 8% NC and no PD were obtained. No major local or general side-effects were noted. CONCLUSION: Electrochemotherapy with cisplatin or bleomycin is an effective treatment of perianal tumors in dogs. The advantages of this therapy are its simplicity, short duration of treatment sessions, low chemotherapeutic doses and insignificant side-effects, as well as the fact that the subject does not have to stay in hospital. (+info)
Lectin histochemistry on squamous metaplasia in different epithelial tumors of dogs.
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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. (+info)
Anal sac gland carcinoma in a cat.
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A perianal mass in a 15-year-old domestic shorthair cat with a history of a firm, painful swelling in the left ventrolateral perianal region was surgically excised and submitted for light microscopic evaluation. Histologically, this was a poorly demarcated, unencapsulated, multilobulated neoplasm that invaded surrounding perirectal skeletal muscle bundles. Lobules were composed of sheets and acinar arrangements of cuboidal to round neoplastic epithelial cells with scant to moderate eosinophilic to amphophilic cytoplasm and a round or oval nucleus with coarse chromatin. Mitotic figures were 2 per 40 x objective field. Acinar lumina sometimes contained eosinophilic proteinaceous material or cell debris. These microscopic features are consistent with anal sac gland carcinoma. This is the second report of this neoplasm in a cat. (+info)
Adjuvant electrochemotherapy for incompletely excised anal sac carcinoma in a dog.
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Canine anal sac gland carcinoma (ASGC) is a frequently described neoplasm that is highly aggressive and can frequently lead to metastatic spread. In this paper, we describe the successful treatment of an incompletely excised ASGC by using cisplatin selectively driven within the tumor cells by trains of biphasic pulses. The dog received two courses of electrochemotherapy 14 days apart. Neither systemic nor local toxicities were detected during the whole course of therapy. The dog is still in complete remission after 18 months. Electrochemotherapy is a safe and efficacious adjuvant therapy for ASGC and warrants further investigation in order to standardize its protocols. (+info)
Biphasic pulses enhance bleomycin efficacy in a spontaneous canine genital tumor model of chemoresistance: Sticker sarcoma.
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