A 4-month-old girl has a firm, purple mass on her shoulder and chest wall that has grown quickly over 2 weeks and is now tense and bruised. She has no fever, and blood cultures are negative. Results: hemoglobin 9.0 g/dL (90 g/L), platelets 12 × 10^3/µL (12 × 10^9/L), fibrinogen 68 mg/dL (0.68 g/L; reference 200-400), PT 15.9 s (reference 11.0-13.5 s), APTT 37 s (reference 25-35 s), D-dimer 9.2 µg/mL FEU (9.2 mg/L FEU; reference below 0.5). The film shows a few schistocytes. Urea and creatinine are normal. What best explains these results?

Localized consumption in a vascular tumor

Sepsis-induced disseminated intravascular coagulation

Immune thrombocytopenia of infancy

Typical hemolytic uremic syndrome

A patient has schistocytes and a platelet count of 22 × 10^3/µL (22 × 10^9/L). Which coagulation pattern favors TTP over DIC?

Long thrombin time and raised FDP

Prolonged PT and APTT, low fibrinogen

Low fibrinogen and a raised D-dimer

A 66-year-old man with septic shock receives no heparin. From day 1 to day 2: platelets 240 to 92 × 10^3/µL (240 to 92 × 10^9/L); fibrinogen 520 to 265 mg/dL (5.2 to 2.65 g/L; reference 200-400); PT 13.0 to 16.8 s (reference 11.0-13.5); D-dimer 1.2 to 7.5 µg/mL FEU (reference < 0.5). What is the best interpretation?

Evolving DIC with fibrinogen consumption

Dilution of factors by intravenous fluids

DIC excluded, as fibrinogen stays normal

Vitamin K deficiency from antibiotics

Disease states: fibrinolytic system and DIC

10 ASCP MLS practice questions on Disease states: fibrinolytic system and DIC, part of Hematology. The first 10 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
A 4-month-old girl has a firm, purple mass on her shoulder and chest wall that has grown quickly over 2 weeks and is now tense and bruised. She has no fever, and blood cultures are negative. Results: hemoglobin 9.0 g/dL (90 g/L), platelets 12 × 10^3/µL (12 × 10^9/L), fibrinogen 68 mg/dL (0.68 g/L; reference 200-400), PT 15.9 s (reference 11.0-13.5 s), APTT 37 s (reference 25-35 s), D-dimer 9.2 µg/mL FEU (9.2 mg/L FEU; reference below 0.5). The film shows a few schistocytes. Urea and creatinine are normal. What best explains these results?
1. ASepsis-induced disseminated intravascular coagulation
2. BImmune thrombocytopenia of infancy
3. CLocalized consumption in a vascular tumor
4. DTypical hemolytic uremic syndrome
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Answer: C · Localized consumption in a vascular tumor
Severe thrombocytopenia, low fibrinogen and a high D-dimer show consumption, and the rapidly growing vascular mass is where it happens: this is the Kasabach-Merritt phenomenon. Platelets are trapped and activated on the abnormal endothelium of a kaposiform hemangioendothelioma or tufted angioma, setting off local clotting and fibrinolysis; common infantile hemangiomas do not do this. Sepsis is unlikely without fever and with negative cultures. ITP and typical HUS do not lower fibrinogen or raise D-dimer this much, and HUS would damage the kidneys. The consumption settles only when the tumor responds to treatment, and platelet transfusions can make the lesion swell.
- A: There is no fever, cultures are negative, and the clotting is centered on the enlarging mass.
- B: ITP lowers platelets only; fibrinogen and D-dimer stay normal.
- D: HUS damages the kidneys, and urea and creatinine are normal; fibrinogen is usually not consumed.
Question 2 · Medium
A patient has schistocytes and a platelet count of 22 × 10^3/µL (22 × 10^9/L). Which coagulation pattern favors TTP over DIC?
1. ALong thrombin time and raised FDP
2. BProlonged PT and APTT, low fibrinogen
3. CNormal PT, APTT and fibrinogen
4. DLow fibrinogen and a raised D-dimer
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Answer: C · Normal PT, APTT and fibrinogen
TTP is caused by severe ADAMTS13 deficiency, which leaves ultra-large VWF multimers that build platelet-rich thrombi. Clotting factors are not consumed, so the PT, APTT and fibrinogen are usually normal. DIC consumes factors and fibrinogen, so it prolongs clotting times and raises D-dimer sharply. An ADAMTS13 activity below 10% supports TTP and calls for urgent plasma exchange.
- A: A long thrombin time with raised FDP reflects fibrinogen loss and lysis, as in DIC.
- B: Prolonged clotting times with low fibrinogen point to consumption, as in DIC.
- D: Low fibrinogen with a high D-dimer is the classic DIC picture.
Question 3 · Hard
A septic patient has platelets 72 × 10^3/µL (72 × 10^9/L), a strongly raised D-dimer, a PT 4 s above the upper reference limit and fibrinogen 130 mg/dL (1.3 g/L). ISTH overt DIC points: platelets 50-100 = 1, < 50 = 2; D-dimer moderate rise = 2, strong rise = 3; PT 3-6 s long = 1, > 6 s = 2; fibrinogen < 100 mg/dL = 1. What is the score?
1. A6, compatible with overt DIC
2. B7, compatible with overt DIC
3. C5, compatible with overt DIC
4. D4, below the overt DIC cutoff
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Answer: C · 5, compatible with overt DIC
Platelets of 72 score 1, a strong D-dimer rise scores 3, a PT 4 s long scores 1, and fibrinogen of 130 mg/dL scores 0 because it is above 100 mg/dL (1.0 g/L). The total is 1 + 3 + 1 + 0 = 5. A score of 5 or more is compatible with overt DIC; a lower score is repeated in 1 to 2 days. The score is used only in patients with a disorder known to cause DIC.
- A: A score of 6 wrongly gives a point for a fibrinogen above 100 mg/dL.
- B: A score of 7 also scores the platelets as if they were below 50.
- D: A score of 4 counts the D-dimer as a moderate rise, not a strong one.
Question 4 · Easy
Which fragment is released only when plasmin digests fibrin that factor XIIIa has cross-linked?
1. AFragment X
2. BD-dimer
3. CFibrinopeptide A
4. DFragment E
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Answer: B · D-dimer
Factor XIIIa joins the D domains of neighbouring fibrin monomers with covalent bonds. When plasmin digests this cross-linked fibrin, it releases D-dimer and larger fragments that contain it. Plasmin acting on fibrinogen or on fibrin that is not cross-linked gives fragments X, Y, D and E, but no D-dimer. A raised D-dimer therefore shows that thrombin made fibrin and plasmin then broke it down, as happens in DIC.
- A: Fragment X is an early plasmin product of fibrinogen as well as of fibrin.
- C: Fibrinopeptide A is cut from fibrinogen by thrombin, before any fibrinolysis.
- D: Fragment E is released from fibrinogen as well as from fibrin.
Question 5 · Hard
A 66-year-old man with septic shock receives no heparin. From day 1 to day 2: platelets 240 to 92 × 10^3/µL (240 to 92 × 10^9/L); fibrinogen 520 to 265 mg/dL (5.2 to 2.65 g/L; reference 200-400); PT 13.0 to 16.8 s (reference 11.0-13.5); D-dimer 1.2 to 7.5 µg/mL FEU (reference < 0.5). What is the best interpretation?
1. AEvolving DIC with fibrinogen consumption
2. BDilution of factors by intravenous fluids
3. CDIC excluded, as fibrinogen stays normal
4. DVitamin K deficiency from antibiotics
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Answer: A · Evolving DIC with fibrinogen consumption
Fibrinogen is an acute-phase protein, so in sepsis it often starts high, and a fall of about half into the reference range still shows heavy consumption. The falling platelet count, lengthening PT and sharply rising D-dimer complete the picture of developing DIC. Trends are more useful than single values, which is why DIC scores are repeated daily. Treatment is aimed at the underlying sepsis.
- B: Dilution does not explain a sharply rising D-dimer.
- C: A fibrinogen that has halved shows consumption even inside the reference range.
- D: Vitamin K deficiency prolongs the PT but does not lower platelets or raise D-dimer.
Question 6 · Easy
In acute DIC, the platelet count and fibrinogen fall mainly because they are:
1. ADiluted by intravenous fluids
2. BCleared by antiplatelet antibodies
3. CUsed up in widespread microthrombi
4. DUnderproduced by marrow and liver
Answer and explanation in LearnFree account
Question 7 · Medium
A 64-year-old man with metastatic pancreatic cancer has had two venous thromboses in a month. PT and APTT are normal, fibrinogen is 430 mg/dL (4.3 g/L; reference 200-400), platelets are 165 × 10^3/µL (165 × 10^9/L) and D-dimer is 4.8 µg/mL FEU (4.8 mg/L FEU; reference < 0.5). These results best fit:
1. AHeparin-induced thrombocytopenia
2. BChronic compensated DIC
3. CAcute decompensated DIC
4. DPrimary hyperfibrinolysis
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Question 8 · Hard
At 34 weeks, a woman with new hypertension has platelets 64 × 10^3/µL (64 × 10^9/L), AST 210 U/L (reference 10-40), LD 980 U/L (reference 120-250), schistocytes and a normal glucose. PT, APTT and fibrinogen are normal, and D-dimer is mildly raised. These results best fit:
1. AAcute fatty liver of pregnancy
2. BAcute obstetric DIC
3. CHELLP syndrome
4. DImmune thrombocytopenia
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Question 9 · Medium
In acute DIC, the thrombin time is prolonged mainly because of:
1. AConsumption of factor VII by tissue factor
2. BLow fibrinogen and interfering FDP
3. CLoss of factors V and VIII
4. DToo few platelets to support clotting
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Question 10 · Medium
Which finding best separates primary hyperfibrinolysis from DIC?
1. AProlonged PT and APTT
2. BRaised fibrin(ogen) degradation products
3. CNormal platelets and near-normal D-dimer
4. DLow fibrinogen and a long thrombin time
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Disease states: fibrinolytic system and DIC

A patient has schistocytes and a platelet count of 22 × 10^3/µL (22 × 10^9/L). Which coagulation pattern favors TTP over DIC?

Which fragment is released only when plasmin digests fibrin that factor XIIIa has cross-linked?

In acute DIC, the platelet count and fibrinogen fall mainly because they are:

At 34 weeks, a woman with new hypertension has platelets 64 × 10^3/µL (64 × 10^9/L), AST 210 U/L (reference 10-40), LD 980 U/L (reference 120-250), schistocytes and a normal glucose. PT, APTT and fibrinogen are normal, and D-dimer is mildly raised. These results best fit:

In acute DIC, the thrombin time is prolonged mainly because of:

Which finding best separates primary hyperfibrinolysis from DIC?