Caterpillar bodies are eosinophilic, elongated, segmented bodies located within the roofs of blisters and are considered to represent a specific histopathologic feature of porphyric bullous eruptions, including porphyria cutanea tarda and erythropoietic protoporphyria. The possibility that similar or identical bodies may be present in other disorders prompted further study exploring the specificity of caterpillar bodies in the differential diagnosis of subepidermal vesiculobullous disorders. Seventy-six cases exhibiting subepidermal clefting were reviewed by light microscopy. “Classic” caterpillar bodies were present in porphyria cutanea tarda (6 of 14) and 1 case representing either venous stasis-associated bulla or possibly bullosis diabeticorum. Caterpillar body-like clusters were present in porphyria cutanea tarda (5 of 14), erythropoietic protoporphyria (1 of 3), bullous pemphigoid (7of 24), and junctional or dystrophic epidermolysis bullosa (3 of 5). In some cases, classic caterpillar body and caterpillar body-like clusters coexisted in a blister roof. Caterpillar bodies or caterpillar body-like clusters were not identified in any cases of dermatitis herpetiformis, linear IgA bullous dermatosis, bullous erythema multiforme, epidermolysis bullosa acquisita, or wound-healing reactions. In contrast to caterpillar bodies, caterpillar body-like clusters were negative for PAS or Type IV collagen stains. In conclusion, caterpillar bodies appear to represent a specific feature of porphyria cutanea tarda (specificity, 98%) but were present in less than half of those cases in this study (sensitivity, 43%). Caterpillar body-like clusters are less specific and may be present in porphyria cutanea tarda, erythropoietic protoporphyria, pseudoporphyria, bullous pemphigoid, epidermolysis bullosa, and epidermolysis bullosa acquisita.
[1]
A. Biggeri,et al.
Efficacy of histologic criteria for diagnosing early mycosis fungoides: an EORTC cutaneous lymphoma study group investigation. European Organization for Research and Treatment of Cancer.
,
2000,
The American journal of surgical pathology.
[2]
C. Magro,et al.
The clinical and histomorphological features of pityriasis rubra pilaris
,
1997,
Journal of cutaneous pathology.
[3]
W. Greene,et al.
Caterpillar bodies of porphyria cutanea tarda ultrastructurally represent a unique arrangement of colloid and basement membrane bodies.
,
1996,
The American Journal of dermatopathology.
[4]
M. Hendrickson,et al.
Reassessment of histologic parameters in the diagnosis of mycosis fungoides.
,
1995,
The American journal of surgical pathology.
[5]
P. Leboit,et al.
Caterpillar Bodies: Distinctive, Basement Membrane‐Containing Structures in Blisters of Porphyria
,
1993,
The American Journal of dermatopathology.