Toxic Epidermal Necrolysis (TEN)

Case Overview

By Danielle Wehle, MD
Educational dermpath case series for dermatology residents

Patient: 70-year-old man 
Lesion Location: Back 

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A biopsy of an acute blistering eruption on the back was performed. Take a moment to review the histologic images below — what’s your diagnosis? 

(Low-power histologic view of blistering lesion)

 

Key Histologic Findings

On examination, several defining features stand out:

• Full-thickness epidermal necrosis
• Subepidermal blistering
• Minimal inflammation

 

(Medium power showing full-thickness epidermal necrosis and subepidermal split)

 

Differential Diagnosis: Three Common Mimickers

 

When evaluating a blistering disorder such as this, several entities in the differential diagnosis come to mind. Let’s walk through the three most likely contenders and highlight what sets them apart.

 

1️⃣ Paraneoplastic Pemphigus

Etiology: Associated with underlying malignancy (most often lymphoma or thymoma); autoantibodies target desmosomal proteins including desmoplakins

Histology:

• Suprabasal acantholysis with keratinocyte necrosis
• Interface dermatitis with lymphocytic infiltrate
• May show combined pemphigus-like and pemphigoid-like features
• Direct immunofluorescence demonstrates IgG and complement deposition on cell surfaces and along the basement membrane zone

 

Key Distinction:

Paraneoplastic pemphigus and TEN both feature keratinocyte necrosis, but paraneoplastic pemphigus shows suprabasal acantholysis and a more prominent inflammatory infiltrate. TEN, by contrast, shows full-thickness epidermal necrosis with minimal inflammation and no acantholysis.

 

2️⃣ Staphylococcal Scalded Skin Syndrome (SSSS)

Etiology: Exfoliative toxins A and B from Staphylococcus aureus cleave desmoglein 1, causing superficial epidermal splitting

Histology:

• Intraepidermal acantholysis at the granular layer
• Subcorneal or intraepidermal split — not subepidermal
• Minimal to absent keratinocyte necrosis
• Predominantly affects neonates and young children

 

Key Distinction:

The critical differentiator is the level of the split. SSSS shows superficial acantholysis at the granular layer, while TEN demonstrates full-thickness necrosis with a subepidermal blister. Age is also a helpful clinical clue: SSSS predominantly affects young children, while TEN is more common in adults and is typically drug-induced.

 

3️⃣ Acute Graft-versus-Host Disease (GvHD)

Etiology: Donor T-cell-mediated attack on recipient epithelium following allogeneic bone marrow or stem cell transplantation

Histology:

• Interface dermatitis with vacuolar change at the dermoepidermal junction
• Apoptotic keratinocytes (“satellite cell necrosis”)
• Lymphocytic exocytosis
• In severe cases, subepidermal blister formation

Key Distinction:

Acute GvHD and TEN can overlap clinically and histologically in severe cases. However, GvHD classically shows interface dermatitis with lymphocytic infiltrate and satellite cell necrosis rather than the pauci-inflammatory full-thickness epidermal necrosis that defines TEN. Clinical history — particularly a recent transplant — is essential.

 

The Final Diagnosis:

Toxic Epidermal Necrolysis (TEN)

The combination of full-thickness epidermal necrosis, subepidermal blistering, and minimal dermal inflammation is diagnostic of TEN. This is a life-threatening disorder most commonly triggered by a medication, often beginning with a flu-like prodrome before progressing to widespread epidermal sloughing involving more than 30% of body surface area. Immediate withdrawal of the offending drug is critical.

 

Key Takeaways for Residents:

• Always assess the level of the epidermal split — subepidermal in TEN vs. superficial in SSSS.
• Minimal inflammation in the setting of full-thickness necrosis is a hallmark of TEN and an important diagnostic clue.
• TEN is a clinical emergency. Accurate pathologic diagnosis directly impacts patient outcomes.

Clinical history is non-negotiable: recent medications, transplant history, or known malignancy each significantly shift the differential.

(Diagnostic high-power image: full-thickness epidermal necrosis with minimal inflammation)

 

📚 Quick Summary

 

Feature	Toxic Epidermal Necrolysis	Paraneoplastic Pemphigus	Staph Scalded Skin Syndrome	Acute GvHD
Full-thickness necrosis	✅ Present	❌ Absent	❌ Absent	❌ Absent
Subepidermal blister	✅ Present	✅ May be present	❌ Intraepidermal	❌ Absent
Acantholysis	❌ Absent	✅ Suprabasal	✅ Granular layer	❌ Absent
Inflammation	❌ Minimal	✅ Prominent	❌ Variable	✅ Interface
Behavior	Life-threatening	Serious	Self-limited	Serious

 

💬 Final Thought

TEN is one of dermatopathology’s most urgent diagnoses. The triad of full-thickness necrosis, subepidermal blistering, and sparse inflammation tells the story quickly at the microscope. Remember: minimal inflammation with maximal destruction? Think TEN.

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