Histo 2 Flashcards
What is anatomy of pancreas
Lobules which supply different groups of cells, islets of langerhans and acinar cells which secrete digestive enzymes
Causes of acute pancreatitis
Obstrucrive
- gallstones
- tumours
- trauma
Metabolic
- alcohol
- hypercalcaemia
- hyperlipidaemia
- drugs (thiazides)
Poor blood supply
- shock
- hypothermia
Infection
- mumps
How does alcohol cause pancreatitis
Spasm of sphincter of oddi and protein rich pancreatic fluid which less viscous
Complications of pancreatitis
Pseudocyst
Abscess
Shock
Hypoglycaemia
Hypocalcaemia
Chronic pancreatitis causes
Metabolic
- Alcohol
- Haemochromatosis
Duct obstruction
- cystic fibrosis as thick mucin
- tumours
Chronic pancreatitis histology
Parenchymal fibrosis with loss of parenchyma
Duct stricture with calcified stones
Lose acinar cells first
Complications of chronic pancreatitis
Malabsorption
DM
Pseudocysts
What characterises autoimmune pancreatitis
IgG4 positive plasma cells
What are the pancreatic carcinomas
Ductal (85%)
Acinar
What are the cystic neoplasms of the pancreas
Serous cystadenoma
Mucinous cystic neoplasm
Pathological precursors to pancreatic ductal carcinomas
Pancreatic Intraductal Neoplasm
Intraducal Mucinous Papillary Neoplasm
K-ras mutations majority of time
Histopathology of pancreatic carcinomas
Adenocarcinomas with mucin producing glands set in desmoplastic stroma
Gritty and grey macroscopically
Complications of pancreatic carcinoma
Local spread
Migratory thrombophlebitis from mucin production into blood
Features of pancreatic endocrine neoplasms
Typically non-secretory
Chromogranin
Associated with MEN1
Most common secretory pancreatic tumour
Insulinoma
Composition of gallstones
Cholesterol (at least 50% cholesterol)- typically single ones which are radiolucent
Pigment- can be multiple which are radioopaque
Histology of chronic cholecystitis
Fibrosis
Diverticula- rokitansky-aschoff sinuses
What are rokitansky-aschoff sinuses seen in
Chronic cholecystitis
Causes of chronic cholecystitis
Gallstones (90%)
Causes of gall bladder cancer
90% gallstones
What are majority of gallbladder cancers
Adenocarcinomas
Difference in volvulus location in children versus elderly
Infants- small bowel
Elderly- sigmoid colon
Acute colitis causes
Infection
Drug/toxin
Chemo
Radiation
Causes of chronic colitis
Crohns
UC
TB
Most common cause of colitis- viral, bacterial, protozoal, fungal
Viral- CMV
Bacterial- salmonella
Protozoa- entamoeba histolytica
Fungal- candida
Who is CMV colitis seen in
Immunosuppressed
Often IBD as treatment is immunosuppresant
Where does acute mesenteric ischaemia occur
Watershed zones
- Splenic flexure
- Rectosigmoid
Histology of crohns
Skip lesions with cobblestone mucosa
Transmural inflammation
Fissues
Sinuses
Non-caseating granulomas
Crohns extraintestinal features
Arthritis
Uveitis
Skin
- pyoderma gangrenosum
- erythema nodosum
- erythema multiforme
Most common IBD
UC
Histology of UC
Inflammation confined to mucosa
Shallow ulcers
Complications of UC
Severe haemorrhage
Toxic megacolon
Adenocarcinoma
Extraintestinal features of UC
Uveitis
Myositis
Arthritis
PSC
Erythema nodosum
Pyoderma gangrenosum
Tumours of colon
Non-neoplastic polyps
Neoplastic epithelial lesions
Mesenchymal tumours
Lymphoma
Where are majority of NET
Gut as largest concentration of NE cells
What are types of polyps in the bowel
Hyperplastic and sessile serrated lesions
Inflammatory
Hamartomatous (Peutz-jeughers)
Peutz jeughers presentation
Intestinal polyps
Freckling of mouth, fingers and toes
Differnece between sessile serrated lesions and hyperplastic polyps
Dysplasia in sessile serrated
Histology of tubular adenomas
Flat surface
Increase in nuclear cytoplasmic ratio
Histology of villous adenomas
Uneven surface
What are polyp factors demonstrate high likelihood of transformation to cancer
Size
Proportion of villous component (villous more so than tubular)
Dysplasia