Gastrointestinal Tumours Flashcards
Describe a malignant melanoma of the oral cavity
Most common canine oral tumour, seen in golden reetrievers, scottish terriers, poodles and dachshunds over represented. Immunohistocheistry may be necessary to diagnose. Locally invasive and highly metastatic. True metastatic rate dependent on size, location and grade. Common sitees: regional lymph nodes and lungs. Recommend surgical excision for tumours easily excised with wide margins. Removal of bone often required for good local control. For non resectable tumours consider coarse fractionated radiation therapy. For medical management, consider carboplatin chemotherapy.
What are the main clinical signs associated Gastrointestinal malignancies?
Oral > ptyalism, dysphagia, halitosis
Oesophageal > regurgitation, dullness, anorexia
Gastric > dullness, weight loss, vomiting
Small intestine > melena, diarrhoea, weight loss
Colon > Diarrhoea, weight loss, tenesmus, hematochezia
Mass lesion, tenesmus > perianal
Describe Squamous cell carcinomas of the oral cavity?
Second most common oral canine tumour. Locally invasive, metastatic rate is variable and dependent on location. Tonsillar SCC has a much higher metastatic rate than more rostral tumours. Sites of metastasis: tonsil, regional lymph nodes and lungs. Recommend surgical excision for tumours easily excised with wide margins. Removal of bone is often required for good local control. Rostral tumours are easier to completely excise. Consider radiation therapy. Consider piroxicam. Cisplatin in combination with has also been reported. Carboplatin is an alternative to cisplatin chemotherapy and is less nephrotoxic. For tonsillar SCC the metastatic rate is high and prognosis is poor.
Describe Fibrosarcoma oral tumours
Occurs less commonly. Variant - histologically low grade but biologically high grade, very locally aggressive and grows rapidly. Metastatic rate around 20%. Lungs are the most common site of metastasis but spread to regional lymph nodes can occur. Recommend surgical excision for tumours easily excised Consider radiation therapy. Inadequate local control results in death more commonly than metastasis. Role of chemotherapy unknown. Prognosis guarded.
What are epulides?
Arise from the periodontal ligament, tend to be slow growing and firm. ay appear similar to gingival hyperplasia. Subtypes include: acanthomatous - locally aggressive tumour, invades underlying bone, common on rostral mandible. Fibromatous: slow growing firm around maxillary premolar teeth. Ossifying: slow growing firm masses, often found around the maxillary premolar teeth. Bony invasion typically dependent on the type of epilus.. Surgical excision for tumours easily excised, removal of bone often required, especially for acanthomatous epulides. Adequate local control is curative, prognosis is excellent.
Describe squamous cell carcinoma in the cat?
Most common feline oral tumour. Risk factors include: use of flea products, diet - tuna, second hand tobacco smoke. Extremely locally invasive. Successful treatment often difficult due to advanced nature of local disease at time of diagnoss. Although uncommon, sites of metastasis include regional lymph nodes and lungs.
Describe fibrosarcoma in the cat
Second most common feline oral tumour. Tumours are locally aggressive but metastatic rate is typically low. Lungs are the most common site of metastasis but spread to the regional lymph nodes can occur.
Describe Gastric tumours in dogs and cats?
The most common gastric tumour in the dog is adenocarcinoma and in cat is the lymphoma. Clinical signs include vomiting, weight loss and inappetence. Microcytic hypochromic anaemia is common due to chronic GI blood loss. surgery typically treatment of choice.
Describe adenocarcinoma gastric tumours?
Most common in dogs. Commonly occurs along the lesser curvature and at the gastric antrum. Reported metastatic rate up to 80%. Sites of metastasis include regional lymph nodes, liver, omentum, spleen and lungs. Surgical excision is treatment of choice, however successful treatment is often difficult due to tumour location and advanced nature of disease at time of diagnosis. Prognosis is good for benign tumours but poor for malignant tumours.
Describe Leiomyoma/leiomyosarcoma Gastric tumours
Leiomyomas are more common in veery old dogs. They can cause paraneoplastic hypoglyaemia. Reported metastatic rate is high. sites of metastasis include: liver and duodenum. Surgical excision is thee treatment of choice. Complete excision is curative for leiomyoma. Successful treatment of leiomyosarcoma is more difficult due to tumour location and advanced nature of disease at time of Diagnosis.
Describe gastrointestinal stromal tumours (gastric tumours)
19% of GIST occur in the stomach. 50% of which stain positively for CD117 (c-kit). Surgical excision is the treatment of choice. PRognosis is guarded to poor.
Describe intestinal and rectal tumours in the dog and cat?
lymphoma is the most common intestinal tumour in dogs & cats. Others include adenocarcionma, leioomyoma and leiomyosarcoma, Gastrointestinal stromal tumour and mast cell tumour. Leiomyoma/leiomyosarcoma occurs more commonly in male dogs. In reports of intestinal adenocarcinoma in cats, siamese cats are over represented. Clinical signs include weight loss, inappetance, vomiting, diarrhoea, melena and/or hematochezia. Microcytic hypocrhomic anaemia is also common due to chronic Gi blood loss. Smooth muscle tuumours have been associated with paraneoplastic hypoglycaemia. Typically surgery is the treatment of choice.
Describe adenocarcinoma of the intestine
most commonly occurs in the large intestine. In the small intestine the most common location is the jejunum. Metastatic rate is moderate. Most common site of metastasis is the regional lymph nodes. Other sites include mesentery, omentum and lungs. Surgical excision with wide margins on either side is the treatment of choice. Chemotherapy for systemic disease is reasonable however exact role of chemotherapy is unknown.
Describe leiomyoma/leiomyosarcoma of the intestine
The second most common intestinal tumour in dogs. Most common intestinal locations are jejunum and caecum. polyuria, polydipsia, anaemia and hypoglycaemia are common clinical findings. Metastatic rate for leiomyosarcoma is low to moderate. Metastasis most commonly occurs to abdominal viscera. Sites include: mesentery, spleen, liver, lymph nodes. Surgical excision with wide margins is the treatment of choice. Complete excision is curative for leiomyoma. Chemotherapy for systemic disease is reasonable.
Describe Gastrointestinal Stromal tumours of the intestine
Large intestine is the most common location. Metastatic rate for GISt is moderate. Metastasis most commonly occurs to abdominal viscera. Sites include liver, lymph nodes and other organs. Surgical excision with wide margins is the treatment of choice. Chemotherapy for systemic disease is reasonable. PRognosis is guarded.
Describe intestinal tumours in the cat.
Adenocarcinoma - most commonly occurs in the small intestine. Sites of metastasis include regional lymph nodes and lungs. Poor prognosis.
What are perianal tumours?
Hepatoid tumours (peranal adenomas/ perianal adenocarcinomas) arise from the sebaceous glands located in the dermis around the anus. Apocrine adenocarcinomas arise from the anal sacs located at the 4 oclock and 8 oclock positions on either side of the anus. Perianal adenoma is the most common histologic type in intact male dogs. perianal adenocarcinomas occur less commonly in both sexes. Apocrine adenocarcinomas are the most common histologic type in femalee dogs. Least common in entact males. Apocrine gland adenocarcinomas frequently associated with paraneopastic hypercalcaemia Castration is the treatment of choice for perianal adenomas in intact male dogs, otherwise conservative excision is often adequate. wide surgical excision is treatment of choice. High rates of local recurrence and metastasis with adenocarcinomas. Perianal tumours rare in cats
Describe Perianal Adenomas
Most common perianal tumour in older, intact male dogs. Development is thought to be androgen dependent. These tumours grow slowly and do not metastasize. Prognosis is good. Rare in cats. Recommend castration for intact male dogs. most tumours will regress over time. For neutered males or female dogs, recommend conservative surgical excision with histopathology of perianal mass. Prognosis is excellent.
Describe perianal adenocarcinomas
Occur in older intact and neutered male and female dgs. Metastatic rate is low but tumours may metastasize more frequently later in the course of the disease. Sites of metastasis include regional lymph nodes, lungs, liver and bone. Rare in cats. Recommend surgical excision for tumours easily excised with wide margins. Even with surgical treatment, local recurrence is common, post op radiation therapy may help reduce likelihood of local recurrence.
Describe apocrine gland adenocarcinoma of the anal sac
Most common perianal tumours in older female dogs. Occur in older dogs. Equal sex distribution. Paraneoplastic hypercalcaemia commonly occurs with this tumour type. Reported incidence is 25–53%. Presenting complaints include tenesmus and or constipation secondary to mass effect from the tumour. Polyuria-polydipsia may also occur secondary to hypercalcaemia.They are locally invasive with a moderate to high metastatic rate. Sites of metastasis include sublumbar lymph nodes, lungs, liver and bone. Rare in cats. Recommend surgical excision for tumours easily excised. Metastatic sublumbar lymph nodes may also be removed, but referral to a specialist is now recommended. For narrowly excised, incompletely excised or non resectable tumours, consider post operative raidation therapy. Various chemotherapeutic drugs have been used for anal sac tumours including cisplatin, carbolatin, doxorubicin, mitoxantrone, and melphalan. Negative prognostic indicators include: tumour size > 10cm, treatment with chemotherapy alone, hypercalcaemia and pulmonary metastasis.
What are hepatobiliary tumours?
Primary hepatobiliary tumours more common in cats, metastatic hepatobiliary tumours are more common in dogs. Of the primary hepatobiliary tumours, malignant tumours rare more common in dogs and benign tumours are more common in cats. Primary malignant hepatobiliary tumours in dogs and cats include hepatocellular carcinoma, biliary carcinoma, neuroendocrine tumour and sarcoma. Hepatocellular carcinoma is the most common primary hepatobiliary tumour in dogs. Biliary cystadenoma is the most common primary hepatobiliary tumour in cats.
Describe hepatocellular carcinomas
Most common primary hepatobiliary tumour in dogs. Paraneoplastic hypoglycaemia has been reported. May be massive nodular or diffuse. Common sites of metastasis include regional lymph nodes, peritoneum and lungs Recommend surgical excision for massive tumours. Prognosis is good with surgical treatment. Local recurrence and metastatic rates are generally low. Prognostic factors include surgery,side of liver involvement (right worse), ALT and AST levels, nodular and diffuse are typically non resectable due to extent to disease. Role of chemotherapy and radiation unknown.
Describe hepatocellular adenomas
Frequently an incidental finding. More common in cats than dogs. Benign tumour. Remove if problematic.
Describe a biliary Carcinoma?
The second most common primary hepatobiliary tumour in dogs. Of malignant hepatobiliary tumours in cats, BC most common. Intraheatic BC appears to be more common in dogs whereas Extrahepatic BC more common in cats, may be massie, nodular or diffuse. Very aggressive biologic behaviour with a high metastatic ratae. common sites of metastasis : lymph nodes, peritoneum ad lungs. Recomend excision for massive tumours. Prognosis guarded to poor. Local recurrence and metastatic rates are high and survival times are short.
What is a biliary cystadenoma?
Frequently an incidental finding - common in cats. Benign tumour. Remove if problematic. Prognosis is good.
What are neuroendocrine tumours?
Rare in dogs and cats. Often are locally Aggresive with nodular or diffuse morphology. Metastatic rate is high. common sites of metastasis: regionaly lymph nodes, peritoneum and lungs. Recommend excision for easily excised tumours. Majority are non resectable due to extent of disease. Prognosis is poor because this disease is highly metastatic. Survival times are short.
what is a hepatobiliary sarcoma?
Rare in dogs and cats. Common primary hepatic sarcomas include haemangiosarcoma, leiomyosarcoma, histiocytic sarcoma and fibrosarcoma. Often are locally aggressive with nodular or massive morphology. Recommend surgical excision for massive tumours easily excised with liver lobectomy. Even with surgical treatment, prognosis is guarded to poor. Local recurrence and metastatic rates are high and survival times are short.
What are exocrine pancreatic tumours?
Rare in dogs. The incidence is slightly higher in cats. Adenocarcinoma is the most common histologic type. Benign exocrine pancreatic masses include adenomas and pseudocysts. Surgical resection s the treatment of choice. Many animals have evidence of metastatic disease at the time of diagnosis. In these, surgery should only be performed for palliative reasons. Pancreatic tumours are locally invasive and the metastatic rate is very high. Common metastatic sites include regional lymph nodes liver and peritoneal cavity.
