This otherwise healthy young woman presented with papules and nodules on her forearms, wrists, and hands. Erythema elevatum diutinum is extremely rare and its etiology unknown, although there have been reports following viral illness, injections, and systemic disease. There are two stages of an individual lesion. Early findings are that of leukocytoclastic vasculitis. Later, as the lesion organizes, it becomes large and fibrotic, almost keloidal. Histologically, these can be mistaken for tumors, including sclerotic fibromas. However, there is an inflammatory component and sometimes vasculitis in the lesion, both unusual for tumors. It probably is more akin to a nodular fasciitis.
Description
At higher power of the mass, the spindle cells are cytologically bland. The peculiar finding is the numerous neutrophils and extravasated red blood cells.