Questions to Ask a Dermatology Expert Witness at Deposition (2026 Guide)

By John Mahoney · Updated 2026-09-01 · 18 questions in 4 concession chains

You are about to cross-examine someone with two decades of training you don't have, on their home turf, about the thing they do every day. That asymmetry is the defining problem of medical-expert depositions — and it gets worse in multi-defendant malpractice cases, where two to four different specialties can be in play in a single case and you have to be conversant in all of them by deposition day.

Dermatology experts testify almost entirely in delayed-melanoma-diagnosis cases, with a smaller set on procedural complications. Melanoma cases are documentation-and-biopsy cases: what the lesion looked like, what was recorded, and what diagnostic doubt required.

The answer to the asymmetry is not to learn dermatology — it is structure. A concession funnel asks the expert to agree, one fact at a time, to propositions so orthodox that refusing them costs more credibility than granting them. The questions below are a generic-case-safe starting bank, organized into the four chains that structure works through.

How to use these questions

Every question below follows three rules of expert cross-examination: it is leading (it states a fact and asks for agreement), it contains one fact (no compounds — a compound question lets the witness answer the easy half), and it belongs to a concession chain (each answer narrows the room the next answer can live in). Ask them in order. When you get the concession, stop — do not ask the "why" question that lets the expert explain it away.

Chain 1 — Qualifications, retention & scope

Goal: establish on the record that this is a paid, retained witness who never touched the patient, and fix the boundaries of what they actually practice.

Doctor, you were retained by opposing counsel in this case, correct?
You are being compensated for your time reviewing this case and for your testimony today, correct?
You never examined or treated the patient in this case, correct?
Everything you know about this case comes from the materials counsel selected and sent to you, correct?
Dermatology relies on dermatopathology for definitive tissue diagnosis — the biopsy is how diagnostic doubt gets resolved, correct?

Chain 2 — Bases-of-opinion lockdown

Goal: freeze the universe. After this chain, any new document, new basis, or new opinion at trial is impeachment material.

You have now told us every document and material you reviewed in forming your opinions, correct?
You are not relying on anything outside that file for the opinions you will give in this case, correct?
You have told us every opinion you intend to offer at trial, correct?
You agree that an opinion you cannot state to a reasonable degree of medical probability is speculation, correct?

Chain 3 — Substantive concessions: melanoma, change, and the biopsy threshold

These concessions are the accepted core of pigmented-lesion practice. They set up the only question that matters: with what this chart documents, what did the standard of care require?

Melanoma can be deadly, correct?
Melanoma is generally more treatable when diagnosed earlier, correct?
A changing pigmented lesion is a recognized warning sign, correct?
When there is diagnostic doubt about a pigmented lesion, biopsy is how that doubt is resolved, correct?
Documenting a lesion’s size and appearance is what allows change to be tracked over time, correct?
A lesion that was never measured or photographed cannot be objectively compared later, correct?

Chain 4 — Closing the doors

Goal: end with the record sealed. These questions convert silence into a commitment that nothing new is coming at trial.

You are not offering any opinions in this case beyond the ones we have discussed today, correct?
You have not held back any opinion or criticism that you intend to offer at trial, correct?
You are not offering any opinion about the pathologist’s reading of the specimen, correct?

These are the generic questions. Your case isn't generic.

The MedLegal AI Examination Builder generates a complete, case-specific concession-funnel roadmap for deposing a dermatology expert — built from your theory of the case, aware of which side you're on and what kind of witness you're facing, with stop markers, if-they-resist branches, and the doors you should not open. Three free cases, no credit card.

Build my examination → Dermatology depo trainer

Where lawyers get burned deposing dermatology experts

Letting the expert retro-stage the melanoma

The defense causation move is to opine that the melanoma was "probably already advanced" at the missed visit — usually without contemporaneous measurements to support it. Pin the basis: what documented finding from that date supports the staging opinion? An opinion staged backward from the eventual pathology is assumption dressed as science.

Missing the sampling-error issues in partial biopsies

A shave or partial biopsy can miss the deepest part of a lesion, and cases turn on whether the technique matched the clinical suspicion. If a "benign" partial biopsy preceded the diagnosis, walk the technique choice separately from the pathology result.

Letting the dermatopathology consult diffuse the clinical duty

Experts point at the pathologist, and the pathologist’s side points back. Keep the clinical chain separate: the decision to biopsy, the technique, the follow-up of the result, and the re-evaluation of a lesion that keeps changing are the dermatologist’s duties regardless of any slide reading.

FAQ

What questions should I ask a dermatology expert witness at deposition?

Work in four concession chains: (1) qualifications, retention, and scope — establish the expert was retained, is compensated, never treated the patient, and what they do and do not practice; (2) bases-of-opinion lockdown — pin every document reviewed and every opinion they intend to offer; (3) the dermatology-specific substantive chain — well-established propositions such as "Melanoma can be deadly"; and (4) closing the doors — confirm on the record that no undisclosed opinions remain. Every question should be leading, contain one fact, and build on the prior answer.

How do I cross-examine a medical expert when I never went to medical school?

You don't out-doctor the doctor — you build concession chains from propositions so well-established that a credible dermatology expert cannot refuse them, then apply those concessions to the facts in the chart. The expert's medical training becomes your asset: the more orthodox the proposition, the more it costs them to fight it. The asymmetry problem is real — especially in multi-defendant cases with two to four specialties — which is why the questions are organized as funnels rather than as debates.

What are the biggest traps when deposing a dermatology expert witness?

The classic traps are letting the expert stage the melanoma backward from the eventual pathology without contemporaneous measurements, ignoring sampling-error issues when a partial biopsy preceded the diagnosis, and letting the dermatopathology consult absorb duties that belonged to the treating dermatologist.

Related resources

Examination Builder — a case-specific concession-funnel roadmap from your theory of the case
Dermatology deposition trainer — the other side of the table: how dermatology witnesses are prepped against these questions
All specialties — deposition question guides
Are you a dermatology physician? Join the MedLegal AI expert network

This page is informational only and is not legal advice. Question banks are generic-case-safe starting points — adapt every question to the facts, the jurisdiction, and your theory of the case before using it in a deposition.