Pseudomembranous changes in the dermis: a novel observation and potential clue for evolving lipodermatosclerosis?

Lipodermatosclerosis (LDS) is a well-recognized form of fibrosing panniculitis. Although chronic cases are readily diagnosed, early and evolving lesions may be clinically mistaken for cellulitis and other forms of panniculitis. Most pathologists are familiar with a pseudomembranous type of fat necrosis as a useful feature of chronic LDS. Although nonspecific, this distinctive pattern of fat necrosis helps in supporting a diagnosis of LDS in the appropriate clinical context. The histopathologic features of early and evolving LDS and those involving the dermis are less well documented. We report a case of early LDS showing extensive pseudomembranous changes in the dermis on a superficial skin biopsy where progression to a classic established lesion was documented clinically. We suspect that this previously unreported and unusual finding may be a histopathologic clue for evolving lesions of LDS.