MRCS Part B Revision · Surgical pathology
Thrombosis — MRCS Part B Surgical pathology
By Dr Richard Miller, MBChB FRCS · Reviewed
Thrombosis is a surgical pathology station. Two of the seventeen examined stations in the MRCS Part B OSCE are surgical pathology. The surgical pathology stations ask you to reason from a specimen, a slide, a report or a vignette to a diagnosis, and then to say what it means for the patient in front of you.
What you need to know for the Thrombosis station
Thrombosis
Thrombus formation is catalysed by damage to the vessel wall causing platelet aggregation and organisation of a haemostatic plug that protrudes into the lumen.
Platelet Adhesion and Aggregation
The first stage involves platelets adhering to damaged endothelium. A dense layer of fibrin and leucocytes then adhere to the surface of the platelets.
Organisation and Haemostatic Plug
A haemostatic plug of fibrin and red cells develop with a further layer of platelets collecting on the surface of the plug. Further platelets are laid down over the initial aggregate and then a further layer of fibrin. These alternating layers of platelets and fibrin form a lamina.
This process causes a differential contraction of platelets and fibrin and gives a rippled appearance known as the lines of Zahn on the thrombus.
What are you asked at the Thrombosis station?
The station runs to 15 questions over nine minutes. These are the questions as they are put to you; the model answers are in the question bank.
- What is your differential diagnosis?
- How would you assess this gentleman acutely?
- How would you manage this gentleman acutely?
- What might an ECG demonstrate in a patient with a pulmonary embolus and why?
- How can DVTs and PEs be reduced in the peri-operative period?
- Describe the causes of thrombosis
- Describe how a thrombus forms in a vessel wall
- What factors might predispose a patient to a thrombus or embolus
- What do you understand by the term ‘embolus’?
- Aside from deep vein emboli what other types of emboli do you now?
- What scoring system might help you to clinically ascertain the probability of a patient having a DVT?
- Is a D-Dimer likely to be useful?
And 3 more at this station.
How is the surgical pathology station marked in MRCS Part B?
Like the anatomy stations, a surgical pathology station is marked out of 20 with all 20 marks going to clinical knowledge and its application. The second of the two may be a microbiology station.
FAQ
What does the Thrombosis station ask?
It opens with "What is your differential diagnosis?" and runs to 15 questions over nine minutes. Like the anatomy stations, a surgical pathology station is marked out of 20 with all 20 marks going to clinical knowledge and its application. The second of the two may be a microbiology station.
How many pathology stations are in MRCS Part B?
Two of the seventeen examined stations. The intercollegiate blueprint titles the second one surgical pathology and/or microbiology, so infection and antimicrobial topics appear here rather than in a station of their own.
How is the pathology station marked?
Out of 20, with every mark awarded for clinical knowledge and its application. There are no communication or professionalism marks available in it.
What should I revise for surgical pathology?
The general processes the syllabus names, inflammation, healing, neoplasia and infection, applied to the specimens and reports a surgical trainee meets. Candidates most often report malignancies and their mutations, inherited cancer syndromes, and obstructive jaundice.
How many stations are in the MRCS Part B OSCE?
Seventeen examined stations of nine minutes each, with a minute to read the task before each one. Two preparation stations and at least one rest station bring the circuit to about twenty, and the exam takes about three and a half hours.
What is the pass mark for MRCS Part B?
There is no published pass mark. The cut score is set separately for Applied Knowledge and Applied Skills, for each circuit, by borderline regression. Published pass rates across the 2024/25 diets ranged from 51% to 66%.
Can I fail a station and still pass?
Yes. There is no rule about how many stations you may fail: the cut score applies to your total mark in each component, so a weak station costs the marks you lost on it and strong stations elsewhere can make them back. Applied Knowledge and Applied Skills are passed separately and must both be passed at the same sitting, so a strong anatomy performance cannot rescue a weak communication one.
Dr Richard Miller, MBChB FRCS
Station summaries are reviewed against the current intercollegiate MRCS syllabus and the published marking blueprint. Guidance changes between diets: check the royal colleges' own pages before relying on a date, a fee or a threshold.
Practise this station
The question bank carries the model answer to every question above, with the rest of the surgical pathology stations.
More surgical pathology stations