pathology 12 - neoplasia 2 Flashcards
name some indirect effects of neoplasia? also called paraneoplastic syndromes.
cachexia hypercalcaemia hypoglycaemia hypertrophic osteopathy paraneoplastic alopecia hepatocutaneous syndrome
name some direct effects of neoplasia? even benign cells could cause these!
compress tissues, compress blood vessels, block tubular organs (pedunculated lipoma in horse intestine), organ rupture, haemorrhage, tumour emboli leading to infarct. eg. kidney.
explain cachexia?
this is an indirect effect of neoplasia - it cause weight loss but due to mostly muscle loss. feeding helps put on fat but not the muscle. probably due to cytokines from neoplastic cells.
explain hypercalcaemia? common in? what do the cells produce?
also an indirect effect of neoplasia. the cells produce PTH like hormone substances. this increases the reuptake of calcium from the bones. common in dogs. common in adenocarcinomas of the anal sac.
adenocarcinoma of anal sacs in dogs often cause hypercalcaemia. what are the two types? why castrate? which commonly metastasise. ?
- neoplasia of gland in wall of anal sac itself. commonly metastasise.
- hepatoids glands which open directly onto surface of anus. - rarely become malignant.
clinical signs of hypercalcaemia?
muscle weakness, cardia arrythmias, anorexia, vomiting, renal failure
explain hypoglycaemia? common in which organ? clinical signs?
common in neoplasms of the pancreatic islets of langerhans. insulinoma. or as a direct effect of other neoplasms. lethargy incoordination muscle weakness seizures
explain hypertrophic osteopathy.? is it rare?
very rare. see in dog/cat. seen as extensive periosteal bone growth in forelimbs. due to space occupying lesion in chest. cause lameness. perhaps blood directed in wrong way.
explain paraneoplastic alopecia?
seen in cats but rare. alopecia on ventrum, legs, footpads
no stratum corneum and inactive hair follicles - shiny/glistening. normally associated neoplasms of pancreas.
hepatocutaneous syndrome? dogs. where found?
also rare. superficial dermatitis. associated to liver disease. scaling, crusting, alopecia.
face, distal extremities, genetalia, footpads.
examples of veterinary neoplasms………canine mast cell tumours? Where found? what are mast cells and where are they found? which gene causes it? what breeds?
mast cells are round cells particularly in mucous membranes and are granular. contain histamine - causes vasodilation.
occurs in dermis and subcutaneous tissues. found on trunk, head, neck, scrotum, tail and back.
predisposed breeds - bull terrier, boxer, cocker spaniel, golden retriever. genes - c-KIT encodes for KIT protein - cell surface growth factor receptor. signals cell to proliferate. (oncogene)
non-cutaneous ones found on conjucntiva, salivary gland, oral cavity, GI tract.
what is the patnaik grading system for mast cell tumours? from benign to malignant!
grade 1 - benign - dermis, monomorphic, mediumsize granules, round nucleus, no mitoses.
grade 2 - dermis & subcutis, pleomorphic round - ovoid nucleus. fine granules, some more than one nucleus, rare mitosis.
grade 3 - deeper tissues, pleomorphic( spindle shaped) no granules, all different nuclei, common mitosis.
neoplasia eg. ovine pulmonary adenocarcinomas - (glandular, malignant, epithelial) ? other types of retrovirus and eg? caused by? what is produced and can be seen on wheelbarrow test?
OPA - retrovirus. beta. (others - alpha, gamma, delta, lenti (HIV IS a lenti). lung neoplasm caused by jaagsiekte virus (jsrv).
either clara cell in terminal bronchus of type II pneumocyte in alveoli - BOTH PRODUCE SURFACTANT!! wheelbarrow test.
causes loss in body weight and exercise intolerance.
firm grey nodules in lungs and clusters of epithelial cells rarely matastasise.
2 systems for OVA or retroviruses to get into cells?
- insertional mutagenesis - insert viral genome into a specific cell in cycle eg. p53. this causes increased expression and replication (insert at an oncogene)
- OPA - have their own oncogene (env gene) which causes cell to become neoplastic.
squamous cell carcinoma? explain type of neoplasia? keratin pearl? commonly seen in?
occurs in eg. white cats due to UV light. maligant neoplasm os squamous epithelia. skin, oral, larynx, oesophagus, stomach, urinary, penis, vulva (sheep docked)
locally invasive and do metastisise. - lymph nodes. see cords/whorls of pleomorphic epithelial cells and may have keratin pearl at the centre. bracken fern toxicity.
