Lab Medicine

lab medicine questions

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Aug 9
A patient with a thyroid nodule and a family history of MEN2 has a markedly raised serum CALCITONIN. Which tumour does this indicate, and which additional marker aids monitoring?
Closed
Aug 8
To screen for early diabetic kidney disease, a urine albumin:creatinine ratio (ACR) on an early-morning spot sample is preferred over a dipstick. Why, and what confirms a positive result?
Closed
Aug 7
A man with fatigue, arthralgia and abnormal liver tests has a fasting transferrin saturation of 60% and a raised ferritin. Which inherited condition should be tested for, and what is the genetic basis?
Closed
Aug 6
A patient has an ELEVATED free T4 and free T3 with a TSH that is NORMAL or mildly RAISED (not suppressed). After excluding assay interference, which two conditions classically cause this 'inappropriate' unsuppressed TSH, and how are they separated?
Closed
Aug 5
A patient in intensive care with sepsis has a LOW free T3, a normal-to-low free T4, and a normal or slightly low TSH, with no history of thyroid disease. What is the most likely explanation?
Closed
Aug 4
During a supervised 72-hour fast a patient becomes hypoglycaemic (glucose 2.2 mmol/L) with HIGH insulin but LOW C-peptide. What does this indicate?
Closed
Aug 3
In a patient with a lower respiratory tract infection, which biomarker rises more specifically with systemic BACTERIAL infection and is used to guide starting and stopping antibiotics?
Closed
Aug 2
A patient has a microcytic anaemia with a normal ferritin, a red-cell count that is high for the degree of anaemia, and basophilic stippling. Haemoglobin HPLC shows an HbA2 of 5.5% (raised). What is the diagnosis?
Closed
Aug 1
A sickle solubility (Sickledex) test is positive. Why is this insufficient to characterise the patient, and which test is definitive?
Closed
Jul 31
An automated full blood count reports an implausibly LOW red-cell count with a very HIGH MCV and a raised MCHC; the film shows red-cell clumping. Warming the sample to 37 °C corrects the indices. What is the cause?
Closed
Jul 30
A patient with a persistently raised haematocrit, aquagenic pruritus and splenomegaly has a LOW serum erythropoietin and is JAK2 V617F positive. What is the diagnosis, and how does the EPO level help?
Closed
Jul 29
A cyanotic patient has a pulse-oximeter reading of ~85% that does not improve with oxygen, yet the arterial pO₂ is normal and the blood looks chocolate-brown. Co-oximetry is requested. What is the diagnosis and why is there a 'saturation gap'?
Closed
Jul 28
A patient has a Coombs-NEGATIVE haemolytic anaemia with spherocytes on the film, a raised MCHC, splenomegaly, and a family history. Which confirmatory test supports hereditary spherocytosis?
Closed
Jul 27
Two patients have a prolonged PT. To distinguish vitamin K deficiency/warfarin from hepatocellular synthetic failure, clotting factors are measured. Which finding indicates liver disease rather than vitamin K deficiency?
Closed
Jul 26
A septic patient develops oozing from venepuncture sites. Labs: prolonged PT and aPTT, LOW fibrinogen, markedly RAISED D-dimer, falling platelets, and schistocytes on the film. What is the diagnosis?
Closed
Jul 25
A patient with lifelong easy bruising and mucosal bleeding has a normal platelet count, a normal PT, a mildly prolonged aPTT, and a low ristocetin cofactor activity (VWF:RCo) with a proportionally reduced VWF antigen. What is the diagnosis?
Closed
Jul 24
To investigate suspected coeliac disease, IgA anti-tissue-transglutaminase (tTG) is requested. Why must a total IgA be measured at the same time, and what should be done if it is low?
Closed
Jul 23
A middle-aged woman with fatigue, pruritus and a cholestatic pattern (raised ALP and GGT) is positive for anti-mitochondrial antibodies (AMA, M2 subtype) with a raised IgM. Which diagnosis is most likely?
Closed
Jul 22
Shortly after anaesthetic induction a patient develops hypotension, bronchospasm and urticaria. Which laboratory test, and with what timing, best confirms mast-cell degranulation (anaphylaxis)?
Closed
Jul 21
Ascitic fluid analysis gives a serum-ascites albumin gradient (SAAG) of 15 g/L (≥ 11 g/L). What does a high SAAG indicate about the cause of the ascites?
Closed