Panniculitis: clinical overlap and the significance of biopsy findings.

BACKGROUND

Panniculitides are well-recognized clinicopathologic entities but the non-specificity of their clinical and pathological features often troubles the diagnostician.

METHODS

This study retrospectively evaluates the clinical overlaps and the significance of histological findings among various panniculitides.

RESULTS

The clinical evaluation in 55 panniculitides cases suggested the diagnosis of typical erythema nodosum (EN) in 26 cases, atypical EN in 17 cases, atypical nodular vasculitis (NV) in two cases, soft tissue infection in five cases and five cases remained unclassified. Skin biopsy evaluation provided definite panniculitis diagnosis in 53 cases including EN (28 cases), leukocytoclastic vasculitis (seven cases), NV (four cases), superficial thrombophlebitis (ST) (two cases), eosinophillic panniculitis (EP) (three cases), infection-related panniculitis (five cases), and one case each of erythema nodosum leprosum (ENL), lupus panniculitis (LP), pancreatic fat necrosis and acne conglobata with two cases remaining unclassified. Histologically, 'predominantly septal' and 'mixed panniculitis' were the chief inflammatory patterns in EN cases, while mixed panniculitis was seen in most LCV cases and predominantly lobular and mixed panniculitis in NV cases.

CONCLUSIONS

Biopsy evaluation of a panniculitis lesion is usually significant, and the application of a combination of histologic features rather than of a single biopsy finding or an inflammatory pattern is helpful in the diagnosis of panniculitis.