## **Core Concept**
Cyanide poisoning is a condition caused by the inhibition of cellular respiration through the binding of cyanide ions to the iron atom in cytochrome c oxidase (Complex IV) of mitochondria. This results in the cessation of aerobic metabolism, leading to cellular asphyxiation. The autopsy findings in cyanide poisoning are often non-specific but can include characteristic changes.

## **Why the Correct Answer is Right**
The correct answer, ., implies that the feature not typically associated with cyanide poisoning at autopsy needs to be identified among the options. Typically, cyanide poisoning is associated with:

- A bright red or pink discoloration of the skin and mucous membranes due to the high oxygen content in the blood (cherry-red discoloration).
- Histological evidence of cellular injury, including vacuolation and necrosis in various tissues.
- The presence of cyanide can sometimes be detected through chemical tests.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not provided, but generally, findings like cherry-red discoloration, are consistent with cyanide poisoning.
- **Option B:** Similarly, not provided, but if related to tissue damage or cyanide detection, it could be a plausible finding.
- **Option C:** Without specifics, if this option describes a common autopsy finding in cyanide poisoning, it's incorrect as the "except" answer.
- **Option D:** This is stated as the correct answer, implying it does not align with typical autopsy findings in cyanide poisoning.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that the **cherry-red discoloration** of the skin is a classic, though not universal, finding in cyanide poisoning. This occurs due to the increased oxygen levels in the venous blood, as tissues are unable to utilize oxygen. This feature is often highlighted in exams for its specificity to cyanide and carbon monoxide poisoning.

## **Correct Answer: D.**