[When to ask for a skin biopsy in a patient with leg ulcer? Retrospective study of 143 consecutive biopsies]

A vascular cause is found in around 85% of leg ulcer patients, but non-vascular causes are also observed. Their diagnosis is based on a set of clinical arguments and skin biopsy with histological analysis. The aim of this study was to analyze the results of these biopsies and to find common criteria for ulcers whose skin biopsies had led to the diagnosis of a non-vascular ulcer.

A retrospective study was carried out on the analysis of 143 skin biopsies of leg ulcers. The reasons for the biopsy were mainly atypical clinical signs and/or the lack of improvement in care after 6 months, as advocated by the French health authorities.

The skin biopsies led to a diagnosis of non-vascular ulcer in 4.9% of cases (7/143), including skin cancer (n=5, 3.5%), cutaneous leishmaniasis (n=1, 0.7%) and Pyoderma gangrenosum (n=1, 0.7%). The univariate statistical analysis revealed that an elevated rim and abnormal excessive granulation tissue were significantly more frequently found in these ulcers. All patients with a positive skin biopsy had associated vascular involvement.

This study found a 5% rate of non-vascular causes of ulcers, mainly skin cancer. Elevated rims and abnormal excessive granulation tissue were the unusual features most commonly found in these ulcers. All patients whose skin biopsy revealed a non-vascular cause had associated vascular involvement. This information confirms the need to perform a skin biopsy, even in the presence of a vascular disease.