NEET-PG 2010

Question 1: Differences between postmortem staining and contusion are all, except:

• A. Margins are regular
• B. Disappear on pressure
• C. Extravasation is found
• D. Bluish in color (Correct Answer)

Explanation: ***Bluish in color*** - Both **postmortem staining (livor mortis)** and **contusions (bruises)** can appear bluish. Therefore, color alone is **not a reliable differentiating factor**. - Livor mortis results from the settling of blood in capillaries, while contusions are caused by the extravasation of blood into tissues due to trauma. *Margins are regular* - **Postmortem staining** typically has **regular, ill-defined margins** that conform to the areas where blood has settled due to gravity. - **Contusions** often have **irregular, well-defined margins** that reflect the shape and force of the impact. *Disappear on pressure* - **Postmortem staining** refers to **livor mortis**, which typically **blanches (disappears) on pressure** during the early stages (up to 8-12 hours post-mortem) as blood is pushed out of the capillaries. - **Contusions** involve extravasated blood in the tissues and **do not blanch on pressure**. *Extravasation is found* - **Extravasation of blood** into the surrounding tissues is a hallmark feature of a **contusion**, indicating a traumatic injury. - In **postmortem staining (livor mortis)**, blood remains within the capillaries and does not extravasate into the tissues; it merely pools due to gravity.