MRCP Part 1 Haematology, Infectious Disease & Dermatology 1 — Questions and Answers
Question 1: A 70-year-old man has a haemoglobin of 70 g/L, MCV 120 fL, and hypersegmented neutrophils on blood film. Vitamin B12 is low. What is the most likely cause of B12 deficiency?
- Dietary deficiency in a vegan
- Pernicious anaemia (Correct answer)
- Terminal ileal resection
- Metformin therapy
Correct answer: Pernicious anaemia
Pernicious anaemia is the most common cause of B12 deficiency in older adults in the UK. It is an autoimmune condition where anti-intrinsic factor antibodies prevent B12 absorption in the terminal ileum. Hypersegmented neutrophils and macrocytosis are classic blood film findings.
Question 2: A patient presents with petechiae, gum bleeding, and a platelet count of 8 × 10⁹/L. Blood film shows no clumping. What is the diagnosis?
- Thrombotic thrombocytopenic purpura
- Immune thrombocytopenia (ITP) (Correct answer)
- Disseminated intravascular coagulation
- Heparin-induced thrombocytopenia
Correct answer: Immune thrombocytopenia (ITP)
Immune thrombocytopenia (ITP) presents with isolated thrombocytopenia (normal white cells and haemoglobin), mucocutaneous bleeding (petechiae, gum bleeding), and no microangiopathic changes on blood film. It is caused by antiplatelet antibodies (anti-GPIIb/IIIa or GPIb/IX).
Question 3: Which marker is used to guide treatment decisions and monitor prognosis in non-Hodgkin's lymphoma?
- Beta-2 microglobulin
- Serum ferritin
- Lactate dehydrogenase (LDH) (Correct answer)
- Alkaline phosphatase
Correct answer: Lactate dehydrogenase (LDH)
LDH is an important prognostic marker in non-Hodgkin's lymphoma, reflecting tumour bulk and cell turnover. It is incorporated into the International Prognostic Index (IPI) for DLBCL, alongside age, stage, performance status, and number of extranodal sites.
Question 4: A patient returning from sub-Saharan Africa presents with fever, rigors, and splenomegaly. Thick and thin blood films show ring forms within red blood cells. What is the treatment for falciparum malaria without complications?
- Chloroquine
- Artemether-lumefantrine (Riamet) (Correct answer)
- Quinine plus doxycycline
- Mefloquine
Correct answer: Artemether-lumefantrine (Riamet)
Artemether-lumefantrine (Riamet) is the first-line treatment for uncomplicated Plasmodium falciparum malaria in the UK. Chloroquine resistance is widespread in P. falciparum. Quinine plus doxycycline/clindamycin is an alternative or second-line option.
Question 5: In disseminated intravascular coagulation (DIC), which coagulation profile would you expect?
- Elevated PT, elevated APTT, elevated fibrinogen, elevated platelets
- Elevated PT, elevated APTT, reduced fibrinogen, reduced platelets (Correct answer)
- Normal PT, elevated APTT, elevated fibrinogen, reduced platelets
- Reduced PT, reduced APTT, elevated fibrinogen, elevated platelets
Correct answer: Elevated PT, elevated APTT, reduced fibrinogen, reduced platelets
DIC is characterised by simultaneous microvascular thrombosis and consumption of clotting factors and platelets, leading to elevated PT, elevated APTT, reduced fibrinogen (consumed), reduced platelets, and elevated D-dimer (from fibrin degradation). Fragmented red cells (schistocytes) may be seen on blood film.
Question 6: A patient with a chronic leg ulcer has a painful, violaceous, undermined border wound. Skin biopsy shows neutrophilic infiltrate without infection. What is the diagnosis?
- Squamous cell carcinoma
- Vasculitis
- Pyoderma gangrenosum (Correct answer)
- Lipodermatosclerosis
Correct answer: Pyoderma gangrenosum
Pyoderma gangrenosum (PG) is a neutrophilic dermatosis presenting with rapidly progressive, painful ulcers with undermined, violaceous borders. It is associated with IBD, rheumatoid arthritis, and haematological malignancy. The pathergy phenomenon (wound worsening after trauma) is characteristic.
MRCP Part 1 Haematology, Infectious Disease & Dermatology 1
A 70-year-old man has a haemoglobin of 70 g/L, MCV 120 fL, and hypersegmented neutrophils on blood film.
Vitamin B12 is low.
What is the most likely cause of B12 deficiency?