Histopathological Features of Rowell Syndrome
The histopathology of Rowell syndrome shows prominent interface dermatitis with basal vacuolar degeneration and apoptotic keratinocytes, consistent with lupus erythematosus, though some cases may demonstrate features overlapping with erythema multiforme including sub-epidermal blistering with keratinocytic necrosis 1, 2.
Key Histopathological Patterns
The histological findings in Rowell syndrome reflect its dual nature as an overlap between lupus erythematosus and erythema multiforme-like lesions:
Lupus Erythematosus Component
- Interface dermatitis with basal vacuolar degeneration
- Apoptotic keratinocytes scattered throughout the epidermis
- Perivascular lymphocytic infiltrate in the dermis
- These features correspond to subacute cutaneous lupus erythematosus patterns 1
Erythema Multiforme-Like Component
- Sub-epidermal blistering with keratinocytic necrosis in some cases 2
- Multiple apoptotic keratinocytes throughout the full thickness of the epidermis (similar to SJS/TEN patterns) 3
- Subepidermal split formation creating bullae
Critical Diagnostic Considerations
A common pitfall is distinguishing Rowell syndrome from pure subacute cutaneous lupus erythematosus, as the annular lesions of SCLE can be confused with erythema multiforme clinically 2. The histological examination becomes crucial when:
- Target-like lesions are present clinically
- Mucosal involvement is evident
- The histological pattern shows distinct features from typical lupus alone
Biopsy Technique
When evaluating suspected Rowell syndrome, obtain:
- Lesional skin biopsy from just adjacent to a blister for routine histopathology
- Perilesional skin biopsy sent unfixed for direct immunofluorescence to exclude immunobullous disorders 3
Controversy and Reality
The existence of Rowell syndrome as a distinct entity remains highly debated 2, 4. The histopathological overlap between lupus erythematosus and erythema multiforme may represent either a true syndrome or simply coincidental coexistence of two separate conditions 4. The distinct histological aspects, combined with dissociated clinical outcomes, support considering it as a singular entity in some cases 2.