CPC's - surgical Flashcards
Where is the appendix located?
- The base of the appendix extends from the caecum.
- It is contained within the visceral peritoneum.
- Its exterior layer is dervived from the taenia coli where the 3 tenaia coli meet at the base of the caecum.
- 2cm from the ileo caecal vavlve
- Average length 8-10 cms
- Can sit:
- Retro-caecal (65-70%)
- Pelvic (25-30%)
- Pre- or post-ileal (5%)
How does inflammation of the appendix cause pain?
Where is the pain felt and why?
- Obstruction causes pressure within the lumen, if continued the presssures oversomes that oft he appendiceal vein, leading to venous outflow obstruction.
- Ischemia begins, if this worsends, thrombosis of the appendicular artery and vein leading to perforation and gangrene
- Midgut visceral discomfort = periumbilical
What are the common symtpoms of appendicitis in addition to pain?
- Periumbilical colic
- Pain shifting to the right iliac fossa from periumbilical region
- Anorexia and Nausea - from dismotility of the gut
- Tenismus: a continual or recurrent inclincation to evacute the bowels
What findings on physical examination suggest a diagnosis of appendicitis?
- General: Fetor (foul odor), fever, tachycardia
- Right iliac fossa: tnederness and guarding maximal over McBurney;s point, rebound tenderness
- Rectal exam: tender anteriorly and to the right in 30%
- Other: pressure in the left iliac fossa produces pain in the right iliac fossa (Rovsings sign)
What are the DDx for Right Iliac Fossa pain?
Should be able to come up with 15.
- Things that kill you: Ectopic pregnancy (young), AAA (old)
- Most likely diagnosis: Appendicitis, mesenteric adenitis, gastroenteritis, Meckel’s diverticulitis
- Renal: UTI, renal colic, acute pyelonephritis
- GIT: Crohns disease, bowel obstruction, cholecystitis, peforated peptic ulcer
- Gynae: Salingitis, ovarian cyst, ovarian torsion (testicular torsion), pelvic inflammatory disease
- Other: Right lower lobe pneumonia, shingles
What questions need to be ask when a patient presents with RIF pain?
- SOCRATES
- Other symptoms: nausea and/or vomiting, changes in bowel habit
- Surigcal and medical Hx: esp previous operations, IBD
- Gynae: sexual activity, last period
- Preparation for surgery: (5 important questions)
- Medications
- Last ate or drunk?
- Bleeding disorders
- Significant cardioresp illness
- Consent
What investigations would you order to confirm a diagnosis of acute appendicitis and rule out DDx of RIF pain?
- UECs: dehydration and renal function
- FBC: leucocytosis, bleeding risk, anaemia
- Serum ßHCG: pregnancy
- Urine analysis: blood, proteint, leucocyte esterase (UTI) and ßHCG (note +ve urinalysis may be found in appendicitis due to secondary ureteruc inflammation)
- US RIF
- CT Abdo
What are the similarities and differences between the appendix and large bowel?
- Similarities: presence of large bowel mucosa, submucosa, lamina propria, muscularis mucosae, muscularis and adventitia.
- Differences: adolescent appendix has prominent lymphoid tissue, there are no Peyer’s patches in the infantile appendix
Desscribe what an acute appendix looks like microscopicaly?
- Exudate in the lumen
- Focal ulceration of the mucosa
- Neutrophilic infiltrate within the wall
- Serosal inflammation
How do you differentiate between acute and chronic inflammation?
- Acute inflammation = presence of neutrophils
- Chronic inflammation = presence of lymphocytes, plasma cells, macrophages.
Define:
- Perforation
- Necrosis
- Perforation: an abnormal opening, especially in a hallow organ
- Necrosis: death of cells in a restricted portion of tissue due to irreversible damage, recognisable by autolytic changes. Histologically this appears as eosinophilic amorphous material, as all of the nuclear details is lost in the dead cells.
What are the possible outcomes of acute inflammation?
- Resolution with or without fibrosis
- Progression to gangrenous appendicitis with necrosis, perforation and peritonitis
- Abscess formation
What it the management of acute appendicitis?
- Do nothing
- Medical:
- If uncomplicated can treat with Abx and delay surgery for 24-48Hrs
- Benefit: establish dx, exclude differentials
- Risk: perforation → peritonitis → long term complications (e.g. infertility, adhesions, retroperitoneal fibrosis)
- If uncomplicated can treat with Abx and delay surgery for 24-48Hrs
- Surgical:
- Surgical drainage
- Appendectomy
What are the neoplastic and non neoplastic tumours of the appendix?
(Draw table)
Describe what can been seen in this microscopic picture?
What is it?
Normal appendix
- Mucosa
- Submucosa
- Muscularis propria
- Adventitia/serosa
- Arrows: lymphoid tissue in the mucosa and submucosa
What are the arrows pointing to?
What is this a picture of?
Normal appendix
- Top arrow: large bowel type glandular epithelium
- Bottom arrow: lymphoid follicle
What is this and why?
Normal appendix of a 3 month old.
Lymphoid tissue not seen in infantile bowel.
What is occuring in this appendix?
Wall thickening due to haemorrhage, oedema and a neutrophilic infiltrate.
What are the differential of right upper quadrant pain?
(At leat 15 DDx)
- Things that will kill you: MI, perforated duodenal/gastric ulcer, AAA dissection, pancreatitis
- Most likely diagnosis: Acute or chronic cholecystitis,
- Anatomicaly:
- GIT: Cholelithiasis, cholangitis, cholecystitis, biliary colic, acute hepatitis, bowel obstruction, appendicitis, liver abcess
- Resp: RLL pneumonia, pleurisy, tension pneuothorax, subdiaphragmatic abscess, PE
- MSK: muscle injury
- Renal: Pyelonephritis, renal colic
- Gynae: endometriosis
What information would you like to know from a patient who presents with RUQ pain?
- SOCRATES
- PMHx:
- gallstones, cholecytectomy IBD, small bowel resection, dyslipidaemia, haemolytic anaemia, sickle cell disease
- Smoking, alcohol, meds (OCP, HRT, fibrates), allergies
- FHx
- POSH
- Preparation for surgery:
- medications
- late ate or drank
- bleeding disorder
- significant cardiorespiratory illness
- consent
What investiagtions would you order for RUQ pain?
- FBC: leucoytosis, anaemia, platelets for bleeding risk and inflammation
- UECs: renal function, dehydration
- LFTs: Cholestatic pattern?, hepatitis?, NAFLD?
- Lipase/amylase: pancreatitis
- Coags: rule out coagulopathies
- AXR: to rule out bowel obstruction, calcified AAA
- US: gallbladdder, liver and biliary tree
What are the consequences and complications of inflammation in the gallbaldder?
- Consequences: resolution, chronic inflammation, abscess formation, necrosis/gangrene
- Complcations: empyema, perforation of the gallbladder, peritonitis, fistula formatiopn, gallstone ileus, septicaemia, adhesions, death
How do you manage a patient who has acute cholecystitis secondary to cholelithiasis?
- IV access: IV fluids and IV Abx - ceftriaxone or gent + amoxy
- Nil by mouth
- Oxygen
- Analgesia: paracetamol 1g PO or oxycodene 5-10mg PO
- Monitor change in vitals or pain and fluid loss
- Consent and book for surgery
- DVT prophylaxis
- Medical: Oral dissolution therapy to dissolve gallstones
- Limted success high recurrence of gallstones
- Medications may have SE on liver
- Surgical: Cholecystecomy
- Benefits (laproscopic): better cosmesis, earlier return to work, shorter hospital stays, lower costs, lower mortality, less post-operative pain
- Relative contraindications (laproscopic): Obesity, pregnancy, end-stage cirrhosis, previous surgery, sepsis.
- Complications of cholecystecomy:
- Leakage of bile
- injury to surrounding structures
- Missed stones - jaundice
- Cholangitis or associated pancreatitis, haemorrhage
Describe the histology of a normal gallbadder?
Layers:
- Mucosa: thrown into folds and bearing short irregular microvilli = uneven surface
- Submucosa
- Muscular layer (not forming distinct layers as in the bowel
- Serosa
- Epithelial lining consists of columnar cells with basally orientated nuclei
What does this gallbladder show? and how does it differ from a normal gallbladder?
The gallbladder demonstrates features of acute inflammation, necrosis and perforation.
- The gallbladder wall is thickenedby fibrosis, in areas there is full thickness necrosis of the wall, an acute inflammatory infiltrate of neutrophils is seen, the mucosa is mostly replaced by necrotic debris.
- The findings that differ from anormal gallbladder are the thickness of the wall, presence of an inflammatory infiltrate and necrosis.
Define metasplasia.
An adaptive transformation of one type of adult fully differentiated tissue into another type of differentiated tissue, not native to the site. Usually induced by a noxious stimulus and represents an adaptive change. May be physiologic as in the uterine cervix, or pathologic as in Barrett’s oesophagus.
Define dysplasia.
Atypical cellular differentiation occuring as a response to chronic noxious stimulus; neoplastic bu pre-invasive; may be observed in the sequence of cellular responses to a potential carcinogen.
What are the potential complications of cholelithiasis?
- Cholecystitis - acute or chronic
- Choledocholithiasis
- Pancreatitis
- Fistula formation
- Gallstone ileus
- Carcinoma of the gallbladder
What is cholangitis? and what can cause it?
Inflammation of the biliary tree. Common causes include:
- Primary: sclerosing cholangitis
- Secondary:
- Biliary obstruction
- Postoperative stricture
- Chronic pancreatitis
- Infections
What are the different tumours of the gallbladder?
(Write up table)
What is Calot’s triangle? Why is it important?
Calot’s triangle is a triangle space, bordered superiorly by the inferior edge of the liver medially by the common hepatic duct and laterally by the cystic duct, where the cystic artery may be found. It helps the surgeon to identify the cystic artery.
What is the pathogenesis of cholesterol stone? and what are the risk factors?
Bile supersaturated with cholesterol leads to precipitation of choelsterol into crystals, which then form gallstones. Pigmented stones are associated with cirrhosis, haemolysis and biliary tract infection.
Risk factors: female, fat, forty and fertile
Also: oral contraceptives, bile stasis, chronic haemolysis, cirrhosis, infection, rapid weight loss, inflammatory bowel disease, terminal ileum resection, total parenteral nutrition, hyperlipidemia, somatostatin therapy.
What are the differential for central colicky abdominal pain?
- Things that kill: AAA, ischaemic gut
- Most likely DDx: gastroenterititis, intestinal obstruction
- Midgut structures: - intraluminal, luminal, and extraluminal causes.
- Gastroenteritis, dulcer ulcer, pancreatitis, intestinal obstruction, ischaemic small or large bowel, inflammatory bowel disease.
- Referred pain: appendix
- Expanded differential:
- renal colic, UTI with pyelonephritis, ectopic pregnancy, twisted or ruptured ovarian cyst, endometriosis.
What further information would you need on a patient with RUQ pain?
- SOCRATES for pain
- Changes in bowel habits - diarrhoea, with blood /mucus, constipation, obstipation, colour of stool, pain on defication, difficulty in defaecation
- Vomiting: fresh blood, coffee ground, bile, feculent, quantity, frequency.
- Fevors, rigors, sweating
- Weight loss, anorexia
- O&G Hx: last menstruation cycle, ?pregnancy
- PHx: previous abdominal surgery, inflammatory bowel disease, renal colic, hernia
- FHx: colonic tumours
- Smoking, alcohol, medications (NSAIDs, corticosteroids, ACE inhibitors)
- Fitness for surgery:
- When last ate or drank
- medications - allergies
- significant medical disorders esp cardiorespiratory illness
- bleeding risks
- blood test results
- is hte patient stable - ie have they been resuscutated re fluids etc.
What would you look for on physical examination in a patient with potential small bowel obstruction?
- Signs of obstruction:
- Crampy abdominal pain
- Vomiting
- Reduced bowel sounds
- Loss of appetite
- Constipation/ unable to pass gas
- Swelling of abdomen
- Signs of the cause of the obstruction:
- Previous surgery: postsurgical adhesions
- Incarcerated groin hernia
- malignant tumour (20%)
- Hernia (10%)
- IBD (5%)
- Volvulus (3%)
- Degree of hydration
- Signs that the obstruction has become complicated
What investigations would you order if you suspect a small bowel obstruction? and why?
- EUC: hydration status, renal function for surgery
- if patient has been vomiting: metabolic acidosis - hypochloremic alkalosis, sometimes hypokalemic too.
- FBC: Hct dehydration, infection, anaemia
- ßHCG: rule out pregnancy
- Amylase/lipase: rule out pancreatitis
- Lactate: non specific for tissue damage
- CXR supine and upright
- Contrast enema
- CT abdo
How do you tell at what level the bowel has been obstructed?
Clinically
Radiologically
- Clinically: location of pain, frequency of colic, history to explain of obstruction.
- Radiologically:
- Small bowel obstruction: central location of distened loops of bowel, complete plicae circulares.
- Large bowel obstruction: plicae semilunares of the large bowel are only partially around the inner circumferes
What does a closed loop obstruction lead to?
Strangulation of the bowel with subsequent necrosis.
What is the management of a small bowel obstruction? 7 points
- IV cannulation
- IV fluid and electrolyte resuscitation - lots of vomiting = K+ replacement
- NBM
- monitor fluid losses:
- NGTinsertion and suction or
- Urinary catheter
- Monitor vital signs, changes in character of pain
- Analgesia
- Consent for surgery
What part of the body is this?
Normal small bowel
What part of the body is this and what is the pathology?
Carcinoid tumour of small bowel.
Cytological features: The cells of the carcinoid ttumour are relatively uniform, with small amounts of pink finely granular cytoplasm. The nuclei are round and contain strippled chromatin.
Architectural features: Characteristically carcinoid tumours grow in small nests or trabeculae of cells. Glandular structures and sheets of cells may also be seen.
A Dx of a carcinoid tumour and decides to order immunohistochemistry (IPX’s)
What is a carcinoid tumour?
A tumour arising from neuroendocrine cells.
What are the principles of immunohistrochemistry? What is the role of immunohistochemistry in a carcinoid tumour?
- Immunohistochemistry aims to demonstrate specific tissue antigens, e.g. cytokeratin filaments of epithelial cells, with peroxidase or fluorescent markers
- Specific antibodies are manufactured against specific tissue antigens, and then these antibodies are bound to colour-marking-systems (peroxidase or fluorescence) that allow detection of positive cases on tissue sections.
- Immunohistochemistry is principally used when light microscopy and histochemical stains are unable to illustrate sufficient features to confidently diagnoise a lesion.
- Immunohistochemistry is employed in the case of a carcinoid tumour to allow for an accurate diagnosis.
What colour do tumour cells stain? Carcinoid tumour.
Where is the stain located - in the cytoplasm or nucleus of cells?
What colour are the mucosal epithelial cells of the small bowel?
- Tumour cell stain brown and the positive staining is located within the cytoplasm.
- Cytoplasmic staining occurs as this is where the neurosecretory granules, identified by immunohistochemistry, are located.
- The mucosal epithelial cells stain blue, due to the presence of hamatoxylin only counter stain. This allows the pathologist to see the basic cytological and archicetural features of the underlying tissue when interpreting the immunohistochemical staining pattern.
What are the clinical features of someone with a carcinoid tumour?
ABCDEF
- Abdominal pain
- Bronchospasm
- Cardiac features (valvular disease)
- Diarrhoea
- Elevated urninary 5-HIAA
- Flushing
Typically where are carcinoid tumours found?
In order of frequency, carcinoids may occur in the appendix (35%), ileum (28%), rectum (13%), and bronchi (13%). Incidence is less than 1% in the pancreas, gallbladder, liver, larynx, testes, and ovaries; however, tumors in these locations frequently metastasize and spread through the mesenteric lymph nodes and portal vein.
What test can be used to monitor carcinoid syndrome?
Urinary 5-HIAA
Carcinoid tumours secrete seratonin and the metabolite of this, 5-hydroxyoxyindole acetic acid, and is excreted in urine and is one means of confirming a suspected diagnosis of carcinoid tumour.
What are the surgical and medical treatments of a carcinoid tumour?
- Surgical: resection of the tumour is the best treatment if feasible, this will reduce tumour mass and obtain symptom remission.
- Medical:
- Somatostatin analog such as octrotide (serotonin antagoist) can ne considered. This relieves the symptoms in 85% of cases and may lead to tumour shrinkage in a small number of patients.
- Chemoembolisation and embolisation with spheres can be used
- In non-resectable tumours chemotherapy can be used
Patients with metastatic disease or carcinoid syndrome there is a 50% 3 year survival.
What features are important in determining the prognosis of a carcinoid tumour?
- No reliable histologic or molecular markers exist to distinguish benign and malignant behaving carcinoid tumours. Metastatic disease is the only true marker of malignacy. Vascular invasion and destructive growth into adjacent organs are also considered markers of malignancy.
- In some carcinoid tumours the behaviour can not be predicted from hte morphologic findgins, these tumours may then be designates as having ‘uncertain malignancy potential’
- However, a tendency for aggressive behaviour correlates with: tumour site and size, depth of invasion, presence of necrosis and mitoses.
- Bad prgnostic factors = ileal/gastric/colonic tumour, >2cm, increased mitosis and presence of necrosis.
Are all carcinoid tumours malignant?
No, in particular those occuring in the appendix and rectum usualy have a benign course and are cured by local exicison.
What other tumours occur in the small intestine?
Draw table
What are the DDx of a breast lump?
- Mastitis
- Breast abscess
- Cyst: galactocele, fibrocystic disease
- Solid lumps: Fibroadenoma, fat necrosis, lipoma, cystosarcoma phylloides
- Malignant: Carcinoma
What further information would you seek from a history in a patient with a breast lump?
- Lump history
- Period history: info about pre, post or peri menopause, menarche
- Children history: number of children, breast feeding?
- FHx: breast disease, other disease
- PMHx: risk factors for surgery
- Meds: OCP, aspirin, NSAIDs and natural products such as fish oil (bleeding risk)
- SHx: occupation, supports
What features would you look for on physical examination in a patient with a brest lump?
- Look at both breasts - sitting/lying +/- manoeuvres
- Feel other breast and feel lump and note:
- Site, size, shape of lesion, skin changes including peau d’Orange, breast and/or nipple asymmetry, nipple changes, inversion, retraction.
- Squeeze nipple: for discharge
- Examine both axillary and supraclavicular lymph nodes, +/- liver
What investigations are appropriate for a breast lump?
- US for younger patients (<35 yo)
- Mammogram for older patients (>35 yo)
- MRI may be useful in patients with breast implants
What is fine needle aspirate cytology?
Who performs a FNAC?
How helpful is it in the diagnosis of a breast lump?
- FNAC is the microscopic study of single cells obtained by sampling a lesion with a narrow gauge (23 or 25) needle. Usually several passes are madwe into the lesion and the aspirated contents are smear onto a slide. The slide is then stained and the cells examined using a light microscope.
- Pathologists, radiologists or surgeons usually perform FNAC
- FNAC is helpful as it may provide a diagnosis. Needs to be taken in light of the clinical and radiological findings, as false positives and false negative diagnoses accur. It allows for triaging of the lesion, neoplastic vs non neoplastic, benign vs malignant, cell type.
- Because of the limitations of FNAc it forms paret of the triple test (clinical, radiological and pathological assessment) and the result should be interpreted in light of the results of these other investigations.
WHat should you tell the patient about FNAC?
Patient needs to know:
- Why the test is being done
- What the test involves
- Risks and complications of the test
- Limitations of the test
What are the risks and limitations of FNAC?
- Risk: Bleeding, pneumothorax, pain, infection
- Limitations: leading to no diagnostic, false positive or false negative results.
- Operator: does not hit lesion
- Technical: non-diagnostic, too much blood, crushed cells, problems with staining
- Pathologist: incorrect interpretation
- Nature of lesion: unable to differentiate between in situ vs invasive malignancy, papillary lesions, mucinous lesions.
- Other traps: mimica - fat necrosis, nodular fasciitis, cellular fibroadenoma.
How does FNAC differ from core biopsy?
- FNAC gives cytological information, but is limited in that it does not give information about the surrounding structures.
- Core biopsy takes a sample of tissue, where both cytology and surrounding architecture is available for examination.
What is this tissue?
Normal breast tissue
What type of tumour of the breast is this?
Fibroadenoma
Benign neoplasm. Proliferation of both glands and stroma. Stromal proliferation frequently distorts the glands into complex anastomosing, ribbon-like profiles as above.
What tumour of the breast is this?
Fibroadenoma
What tumour of the breast is this?
Lobular carcinoma in situ.
Neoplastic proliferation of epithelial cells confined to the termial duct lobular unit. Has a distinctive “bags of marbles” appearance. Cells are small, uniform, bland and distend the acinar units
What tumour of the breast is this?
Ductal carcinoma in situ
Ducts distended by large malignant cells with central necxrosis and calcification (comedo necrosis).