Macroscopic Description of Mesothelioma

Diffuse lesion that spreads in the pleura space, ensheathing and invading local tissue that is usually associated with a pleural effusion.

Microscopy of Mesothelioma

Mixture of two cell types, one of which may predominate.  Mesothelial cells can differentiate into either epithelioid cuboidal, columnar or flattened cells forming tubular or papillary structures resembling adenocarcinoma (epitheliod type).  Particular immunohistochemistry staining needed to differentiate from metastatic disease.

Electron Microscopy of Mesothelioma

Presence of long tonofilaments but absent microvillous rootlets and lamellar bodies.  The mesenchymal type of mesothelioma appears like a spindle cell sarcoma (sarcomatoid type).  The mixed type of mesothelioma contains both epithelioid and sarcomatoid patterns.

Clinical Symptoms of Mesothelioma

Chest pain, dysponoea and recurrent pleural effusions.  Lung is invaded directly and there is often metastatic spread to the hilar lymph nodes, liver.

Prognosis of Mesothelioma

50% die within 12 months of diagnosis, few survive beyond 2 years.  Aggressive surgical, chemotherapy, and radiotherapy may improve the poor prognosis.  Mesothelioma in the peritoneal cavity associated with heavy asbestos exposure may occur.  Other sites you can have mesiothelioma: pericardium, tunica vaginalis, and genital tract.

How to contact Mayo Medical School to set up your medicine electives:

Mayo Medical School

200 First Street

SW Rochester, MN

55905

Telephone Number: +1 507 284 3671

Fax Number: +1 507 284 2634

How to contact Georgetown University to set up your medical clarking elective:

Georgetown University School of Medicine

3900 Reservoir Road

NW Washington, DC

20007

Telephone Number: +1 202 687 1154

Diarrhoea questions

Diarrhoea is subjective, and can be defined as an increase in the volume, frequency or fluidity of stool relative to normal for the patient. Dysentery is diarrhoea with the presence of blood, mucous and protein in the stool, and often associated with signs and symptoms of systemic illness, e.g. fever, weight loss, anorexia, abdominal pain and dehydration.

Acute diarrhoea can be categorised into (a) osmotic; (b) secretory; (c) inflammatory and (d) dysmotility. With osmotic diarrhoea, fasting usually results in resolution of the diarrhoea, but with secretory diarrhoea fasting probably will make no difference.

• Causes of osmotic –> laxatives, antacids, other drugs, congenital malabsorption
• Causes of secretory –> bacteria, viruses, certain drugs. Faecal RBCs and WBCs uncommon; systemic symptoms uncommon
• Causes of inflammatory –> invasive bacteria and parasites, inflammatory bowel disease, chemotherapy and radiotherapy. Faecal RBCs and WBCs common; systemic symptoms common

Questions to ask:

• Volume, frequency and character of stools?
• Blood/mucous in stool?
• Onset and duration? Onset in relation to pain (which came first)? –> if diarrhoea first then pain, gastroenteritis likely
• Does anything, e.g. eating/drinking, exacerbate/relieve diarrhoea?
• Has the patient tried any medication for the diarrhoea? Has it worked?
• Associated features? –> nausea, vomiting, fever, abdominal pain, constipation
• Is diarrhoea the biggest problem, or are there other more pressing concerns?

• HIV, transplants, malignancy, chemo/radiotherapy, abdominal surgery?
• Past history/family history of diarrhoeal diseases?

• Anyone else around you have diarrhoea? Are you associated with day care centres?
• Recent dietary history à recent consumption of meats (cooked, uncooked), eggs, seafood, dairy foods and unusual foods
• Recent travel to developing countries? Recent outdoor activities such as bushwalking? If so, what was the food + water situation?

A summary of epidemiologic questions:

Causes of infectious colitis:

(a) Campylobacter spp. Most common diagnosed cause of bacterial diarrhoea. Backpacker’s diarrhoea; contaminated food/water. Summer months. ~1wk duration. Very young children, and young adults. Prodrome of fever, headache, myalgia and abdominal cramps. Faecal WBCs and RBCs.

(b) Salmonella spp. Cafeteria/restaurant outbreaks, family gatherings. contaminated food/water (eggs/poultry). Summer months. Very young and very old. Prodrome of fever, headache, myalgia and abdominal cramps. Faecal WBCs (and RBCs, but not so much).

(c) Shigella spp. person to person spread; within families, day care. Sudden onset fever, headache, myalgia, abdominal pain. Faecal WBCs and RBCs

(d) Y. enterocolitica person to person and contaminated food/water. Fever, RLQ abdominal pain. Mimics appendicitis. Faecal WBCs and RBCs.

(e) V. parahaemolyticus raw/undercooked seafood. Sudden onset fever, headache and abdominal pain. Faecal WBCs and RBCs.

(f) EHEC 0157:H7 contaminated food/water, meat, outbreaks in institutions, day care. Fever, abdominal cramps, very bloody stools. Can be complicated by HUS and TTP. Faecal WBCs and RBCs.

(g) E.histolytica contaminated food/water, travel in developing countries. Sudden onset fever, abdominal cramps, bloody diarrhoea (amoebic dysentery). Faecal WBCs and RBCs.

(h) C. difficile after treatment with Abx (especially clindamycin) and antimotility agents, and especially in hospital setting. Fever, abdominal pain, bloody stools. Faecal WBCs and RBCs. Toxin destroys colonic mucosa.

Investigations:

• Haemoccult and faecal cell count
• C. difficile toxin
• E. coli 0157:H7 toxin
• Stool bacterial culture
• Stool microscopy for ova and parasites

Chest pain questions:

Where –> system involved

What –> pathology

How –> functional limitation

Why –> aetiology

1. Patient’s age
2. SOCRATES – site, onset, character, radiation, associated symptoms, time course, exacerbating/relieving factors, and severity.

Character:

• crushing or pressure –> cardiac
• tearing pain through to back –> dissection
• sharp, stabbing –> pulmonary
• burning, ‘indigestion’ –> GI

…but be careful with character, because there is lots of overlap

Onset:

• exertional –> IHD
• progressive onset at rest –> MI
• sudden onset –> PE, dissection or pneumothorax
• after meals –> GI

Location: superficial and localised –> somatic

Radiation:

• to the back –> dissection, pancreatitis, posterior ulcer (MI possible)
• arms/neck/jaw –> IHD
• located primarily in the back, especially interscapular –> dissection

Duration:

• maximal at onset –> aortic dissection
• lasts only for a few minutes –> IHD

Exacerbating/relieving factors:

• worsens with exertion, relieved with rest –> IHD
• related to meals –> GI
• worsens with respiration –> pulmonary, pericardial and musculoskeletal

Associated Sx:

• haemoptysis –> PE
• dyspnoea –> CV or pulmonary
• nausea and vomiting –> CV or GI

Previous episodes; ask about testing (ECG, echo or angiography)

1. Specific questions –

• HoPC:

· Associated with dyspnoea? Worse when lying down (orthopnoea)? How many pillows do you sleep with? Do you wake up at night, gasping for breath (paroxysmal nocturnal dyspnoea)?

· Ankle swelling (symmetrical and worse in the evening, but improves overnight)?

· Palpitations? Are they of sudden or gradual onset (cardiac arrhythmias are instantaneous, sinus tachycardia is slow onset)? Are they associated with pain, dyspnoea or faintness? Ask patient to tap out beat.

· Syncopal episodes (episodes of fainting)? Do they occur when standing up suddenly? Ask about anti-anginal and antihypertensive drugs that may cause postural hypotension. Do they occur with exertion?

· Intermittent claudication?

· Fatigue?

· Anorexia?

· Weight loss?

· Fever?

· PMH:

· Smoker?

· Heart attack? Other heart problems? (IHD)

· Hypertensive? (IHD)

· Lipid profile? (IHD)

· Diabetic? (IHD)

· Trauma? (pancreas)

· Gallstones? (choledocholithiasis)

· Asthma? (eosinophilic oesophagitis)

· Reflux? (GI)

· Ulcers? (GI)

· Pancreatitis? (GI)

· Recent long-distance travel or other long period of immobilization?

· Previous surgery? To abdomen? (cholecystectomy, pancreatectomy)

· Previous gastroscopy/colonoscopy?

· Medication:

· NSAIDs? Aspirin? Alcohol? à all potential causes of gastritis

· Alcohol consumption? (pancreas)

· Any recent changes to medications?

· FH:

· Cancer?

· Cardiac disease?

1. Questions to ask all the time:

· Smoker?

· Appetite?

· Weight loss?

· Any recent changes to medications?

· Allergies?

· Diabetic?

Differential Diagnoses:

CV aetiologies:

• AMI
• Aortic dissection
• Angina
• Pericarditis

Pulmonary aetiologies

• PE
• Pneumonia
• Pneomothorax
• COPD/Asthma exacerbation
• Lung cancer

Gastrointestinal aetiologies

• GORD
• Gastritis – pain not associated with dyspnoea or exertion, and not very severe
• Peptic ulcer disease – chronic pain assoc/w food; lasts hours-days
• Oesophageal spasm/eosinophilic oesophagitis/achalasia
• Pancreatitis
• Cholecystitis/choledocholithiasis
• Acute Hepatitis

Musculoskeletal aetiologies

3 major life-threatening possibilities:

*AMI*

*PE*

*Aortic dissection*

Abdominal pain questions:

Where –> system involved

What –> pathology

How –> functional limitation

Why –> aetiology

1. Patient’s age
2. SOCRATES – site, onset, character, radiation, associated symptoms, time course, exacerbating/relieving factors, and severity.

Character:

Onset:

• constant pain rather than intermittent = worse

Location: correlate with organs potentially affected

Radiation: started centrally and migrated to RIF = appendicitis

Duration: shorter duration = worse

Exacerbating/relieving factors:

• sitting forward = pancreatitis
• not moving around, lying rigid = peritonism

Associated Sx:

• nausea and vomiting à if vomiting follows pain = worse
• others covered below

Previous episodes (no prior episodes = worse); ask about testing (endoscopy)

1. Specific questions –

• HoPC:

· Nausea and vomiting? Contents of vomit?

· Diarrhoea/constipation?

· Blood in stool? In toilet bowl?

· Normal urinary function?

· Jaundice? Who noticed it?

· Fatigue?

· Anorexia?

· Weight loss?

· Fever?

· PMH:

· Smoker?

· Diverticulosis? (diverticulitis)

· Gallstones? (choledocholithiasis)

· Ulcers? (GI)

· Pancreatitis? (GI)

· Heart attack? Other heart problems? (IHD)

· Hypertensive? (IHD)

· Lipid profile? (IHD)

· Diabetic? (IHD)

· Trauma? (pancreas)

· Previous surgery? To abdomen? (cholecystectomy, pancreatectomy)

· Previous gastroscopy/colonoscopy?

· Medication:

· NSAIDs? Aspirin? Alcohol? –> all potential causes of gastritis

· Antibiotics/steroids? –> may mask infection

· Alcohol consumption? (pancreas, liver)

· Any recent changes to medications?

· FH:

· Cancer?

· Cardiac disease?

1. Questions to ask all the time:

· Smoker? Alcohol?

· Appetite?

· Weight loss?

· Any recent changes to medications?

· Allergies?

· Diabetic?

Causes by location of pain:

Differential Diagnoses:

(a) Life-threatening

· Ruptured ectopic pregnancy à women of childbearing age; risk factors include PIF, STDs, intrauterine contraceptive device. Sharp, severe localised pain rarely on midline. May be shocked if there is haemorrhage. b-HCG and transvaginal US.

· Ruptured/leaking AAA –> risk factors include CAD, hypertension, DM, smoking. Epigastric pain radiating to back/groin. May be shocked. Plain abdo X-Ray and Spiral CT.

· Mesenteric ischaemia –> risk factors include IHD, DM, hypertension. 70% mortality. Colicky pain. CT/MRI/angiography.

· Bowel obstruction –> History of previous abdominal surgery. Vomiting, colicky pain, distention and constipation (initially diarrhoea). Increased bowel sounds. Plain abdo X-Ray.

· Perforated bowel –> History of peptic ulcer disease/diverticulosis. Acute onset epigastric pain (peptic ulcer) common; may localise due to walling off, or spread. Localised/generalised peritonitis. Decreased bowel sounds, fever and tachycardia. Plain abdo X-Ray shows free gas below diaphragm.

· Pancreatitis –> serum amylase/lipase, US and CT.

(b) Common

· Peptic Ulcer –> all age groups; assoc/w H. pylori, NSAIDs, Aspirin, smoking and alcohol. Epigastric pain 1-3 hours after food that’s relieved by food/antacids. Pain can awake patient at night. If perforation, presentation will be more severe. Give PPI, then gastroscopy and blood test for H. pylori.

· Acute appendicitis –> most common young adulthood. Umbilical pain that migrates to RIF over hours. If perforation, peritonitis and more severe systemically. Assoc/w low-grade fever and anorexia. WCC.

· Choledocholithiasis/cholecystitis/ascending cholangitis –> most common 30-50. RUQ pain that radiates to R. subscapular area. May be associated with fever and peritonitis (cholecystitis/cholangitis), jaundice and nausea and vomiting (all). WCC, amylase and US.

· Renal colic –> most common 30-40. Loin to groin pain, very severe. Assoc/w nausea and vomiting. Urinalysis (haematuria) and IV pyelography.

· Diverticulitis –> more common with age. LIF pain associated with fever, nausea and vomiting and change in bowel habit. Plain abdo XRay and barium enema.

· Acute gastroenteritis –> may be seen in multiple family members. Non-specific abdominal pain that follows nausea and vomiting, and assoc/w watery diarrhoea and fever. This is the last diagnosis after process of elimination.

· Important extra-abdominal causes:

• • DKA
  • MI
  • Pneumonia
  • PE
  • Sickle cell crisis

Confusion and syncope

Confusion is a symptom, not a diagnosis. Confusion is a recent alteration in higher cerebral functions such as memory, attention and awareness (not alertness or consciousness). There is a broad range of severity of confusion; it can be as minor as a disturbance to short-term memory, to an inability to relate at all to the surrounding environment, and process sensory input (delirium).

There are four groups of disorders that account for most cases of diffuse cortical dysfunction:

• Exogenous toxin
• Drug withdrawal
• Primary intracranial disease
• Systemic diseases secondarily involving the CNS

There are two groups of patients with confusion that require urgent attention:

• Hypoglycaemics
• Hypoxaemics

Therefore, in any patient with confusion it is important to conduct pulse oximetry and bedside BSL testing. Vital signs are important; if patient hyperthermic, consider infection and find possible source. Similarly, lungs auscultation may reveal ischaemia.

Differential diagnoses:

• Cerebral hypoxia
  • AMI
  • Respiratory failure
  • CHF
• CNS infection
• Elevated ICP
• Systemic
  • Hypoglycaemia
  • Sepsis
  • Hepatic encephalopathy
• Intoxication and withdrawal (not just from illicit substances but from prescribed medication)
• Medication side-effect
• Trauma
• Subarachnoid haemorrhage

Basic investigations:

Syncope questions

The final common pathway for all causes of syncope is dysfunction of both cerebellar hemispheres or brainstem. It is a transient LOC. The life-threatening causes of syncope are primarily cardiovascular in origin.

The causes of syncope can be categorised into:

• Syncope due to hypoperfusion
  • Focal hypoperfusion of CNS
    • Cerebrovascular disease
    • Subarachnoid haemorrhage
  • Systemic hypoperfusion
    • Aortic stenosis
    • AMI
    • Tachycardia
    • VF
    • 2^nd or 3^rd degree heart block
    • Aortic dissection
    • Neurocardiogenic (vasovagal)
    • Miscellaneous reflex
• Syncope not due to hypoperfusion
  • Hypoglycaemia
  • Hypoxia
  • Seizure
  • Drug-induced
  • CO poisoning

Life-threatening causes of syncope:

• Hypovolaemia/haemorrhage
• AMI
• Arrhythmias
• Aortic stenosis (severe)
• Hypoglycaemia
• PE
• Subarachnoid haemorrhage
• Stroke

Questions to ask:

(a) What actually happened in the syncopal event (character of event)? Key elements include (i) setting (e.g. postprandial), (ii) rate of onset, (iii) standing, sitting or supine at time of onset, (iv) duration and (v) rate of recovery. Sudden onset while sitting/supine and more than a few seconds duration à think serious (cardiac) cause.

(b) What happened before the event? –> preceded by exertion (outflow obstruction), emotional stress, urination, defecation (reflex syncope), aura (seizure)

(c) Associated symptoms? –> chest pain or breathlessness (AMI/PE), gray/black vision (neurocardiogenic), incontinence of urine/stool (seizure)

(d) Past medical history?

· Cardiovascular disease? Arrhythmias? Valve problems?

· Diabetic? (at risk of hypoglycaemia)

· Recent surgery?

· Recent bleeding? Vomiting? Diarrhoea?

(e) Medications? –> beta-blockers, CCBs, ACE-Is, insulin and oral hypoglycaemics, diuretics, Digoxin

(f) Recreational drug use?

(g) Occupation? (CO poisoning)

Questions to ask all the time:

· Smoker?

· Appetite?

· Weight loss?

· Any recent changes to medications?

· Allergies?

· Diabetic?

Some causes and their clinical features:

• Arrhythmia –> abrupt onset and rapid recovery
• Outflow obstruction –> related to exertion; rapid recovery
• AMI –> recovery often incomplete
• PE –> dyspnoea and recovery often incomplete
• Aortic dissection –> recovery often incomplete
• Subarachnoid haemorrhage –> focal neurologic findings

Most important investigations = ECG, postural BP, then Ix according to D.Dx.

I managed to pass all my OSCE’s from my last clinical rotation block so I was really excited about that.  The rotation that I was on was boring as hell and I’m pretty sure I will not be pursuing a career in that particular field of medicine.  I’m hoping general surgery will be better.

My first day on general surgery was pretty uneventful.  I got to go into theatre to see a laparoscopic cholesystectomy.  That was pretty cool.  Surgery does bring the anatomy to life.  Note to self: review anatomy.  However, the highlight of my night was being bitched at by an angry 60 year old nurse who clearly was annoyed that there were students invading her nurse’s station.  If I wasn’t such a nice guy, oh who am I kidding, I gave her a dirty look while talking about her to a colleage as we walked away.  There is no need to be a bitch at work.  I realise that your job is shitty, but being angry all the time is certainly not good for your health.  I don’t know maybe it’s just me, but I find that the younger nurses are much more helpful and inviting.  It was interesting to see that when the doctor came around the 60 year old nurse changed into a completely different person… needless to say all her sphincters clenched up nice and tight.

I think I’m going to enjoy general surgery.  It will give me a chance to practice my cannulation technique - which is pretty shotty at the moment.  The patients themselves are pretty nice even when you miss the vein or go in too far.  Note to self: review anatomy.  The only time when they’re reluctant to talk to you is when they’re in a lot of pain or feeling noxious.  When a patient says, “Get the F*** out of here!” or project their vomit at you, it’s a pretty good indication for you to be running in the opposite direction.

Medical School Gossip Update

The ugly people in my class are either married or engaged.  How the hell did this happen?  I come back from the summer and people are hooking up and getting married.  I can’t even think about marriage at the point.  I think my first wife will come at 35 and then probably a divorce shortly after that? I don’t know.  It’s something to aim for I guess.  Although seeing these people get married gives me hope that there is somebody out there for everybody.

Third Year is going to be awesome…