Leg Ulcers

Clinical

A clinician usually biopsies an ulcer if he thinks it is a malignancy or if it looks like an ulcerating atypical mycobacterial infection. Hopefully the biopsy is an incisional one with a bit of surrounding normal skin. Sometimes a clinician thinks an SCC is developing at the edge of a very chronic venous ulcer but remember the pseudoepitheliomatous hyperplasia may be seen around the edge of a healing ulcer.

Ulceration due to vasculitis is rare but can be seen in polyarteritis nodosa and rarely in a rheumatoid arthritis.

 Clinicians seldom biopsy venous or arterial ulcers or neuropathic ulcers for that matter as the diagnosis is made on clinical features. See image below.

Atypical self induced ulcers may score a biopsy especially if they occur on the face but watch the trigeminotrophic syndrome in these situations.

Pyoderma gangrenosum is again often a clinical diagnosis. Pain and the bluish undermined edge with a rapid evolution in a suitably predisposed patient makes the diagnosis relatively easy.

Ulceration can occur in a lesion of necrobiosis lipoidica but an adequate biopsy of surrounding tissue should show the histological features of that condition.

Histological Clues

Pyoderma Gangrenosum - Histopathology in an early case may show a full thickness neutrophilic infiltrate but later partially healing stages are non diagnostic. Many ulcers have neutrophils in the base.

Venous ulcers will have vascular proliferation in the upper dermis with fibrinous occlusion of superficial vessel walls.

Atrophie blanche is a curious condition seen on the medial ankle characterised histologically by a hyalinising vasculitis accompanied by the clinical picture of an area of white scarred skin studded with red vascular dots.

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