Injuries: histology of the electrical mark: practice question

A Forensic Medicine question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Forensic Medicine · Injuries: histology of the electrical mark

Sample item

A farm worker is found dead beside a faulty pump. On his fingertip is a small, pale, crater-like lesion with a raised rim. Which microscopic finding would best support an electrical mark?

ADense neutrophil infiltrate with fibrin in the dermisBFresh extravasation of red cells in the subcutis onlyCHaemosiderin-laden macrophages beneath the epidermisDElongated, palisaded epidermal nuclei with honeycomb vacuolation

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

D. Elongated, palisaded epidermal nuclei with honeycomb vacuolation

The electrical mark is produced by Joule heating at the point of contact. Histology shows elongated, palisaded nuclei in the epidermis with vacuolation that gives a honeycomb appearance, often with deposited metal from the conductor. These changes help to separate the mark from simple thermal burns.

Option by option

A. Dense neutrophil infiltrate with fibrin in the dermis
Neutrophil infiltration is a delayed inflammatory response and suggests an older burn.
B. Fresh extravasation of red cells in the subcutis only
Fresh haemorrhage is a feature of bruising and not of electrical marks.
C. Haemosiderin-laden macrophages beneath the epidermis
Haemosiderin suggests an older bruise, not a recent electrical lesion.
D. Elongated, palisaded epidermal nuclei with honeycomb vacuolation (correct)
Correct. Nuclear streaming and vacuoles in the epidermis are the typical electrical change.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Forensic Medicine question

What is the answer to this Forensic Medicine question?

The best answer is D, Elongated, palisaded epidermal nuclei with honeycomb vacuolation. The electrical mark is produced by Joule heating at the point of contact.

Why is "Dense neutrophil infiltrate with fibrin in the dermis" not the answer?

Neutrophil infiltration is a delayed inflammatory response and suggests an older burn.

Why is "Fresh extravasation of red cells in the subcutis only" not the answer?

Fresh haemorrhage is a feature of bruising and not of electrical marks.

Why is "Haemosiderin-laden macrophages beneath the epidermis" not the answer?

Haemosiderin suggests an older bruise, not a recent electrical lesion.

What concept does this question test?

It tests Injuries: histology of the electrical mark in Forensic Medicine. Histology shows elongated, palisaded nuclei in the epidermis with vacuolation that gives a honeycomb appearance, often with deposited metal from the conductor. These changes help to separate the mark from simple thermal burns.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Injuries: histology of the electrical mark?

Learn postmortem changes with their timelines, and toxicology as poison, sign, test and antidote. Then use the flashcards and the other Forensic Medicine questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.