Abstract
Background: Folliculotropic mycosis fungoides (FMF) is a rare cutaneous malignancy that can be confused with other inflammatory diseases, such as discoid lupus erythematosus (DLE), due to the variety of histopathological findings. Methods: This study aims to describe histopathologic patterns common to DLE using 12 biopsies from patients with a confirmed diagnosis and compares these features to known FMF histopathologic patterns. Results: The most frequent histopathologic pattern was folliculocentric/folliculotropic pattern, with no follicular mucinosis. Plasma cells and mild cellular atypia were present in all biopsies. Other common findings included follicular plugging, syringotropism, interstitial mucin, and a lichenoid interface. Less common findings included epidermotropism, follicular hyperplasia, and eosinophils. None of the biopsies had comedones, granulomas, folliculitis, follicular mucinosis, or spongiosis. Conclusion: While some histopathological features present in DLE overlap with features found in FMF, such as folliculotropic patterns, follicular plugging, and syringotropism, differences do exist. FMF biopsies tend to also have keratin-filled cysts and comedones, granulomas, eosinophilic or suppurative folliculitis, folliculolymphoid hyperplasia, and occasionally, follicular mucinosis. Therefore, when making a diagnosis of FMF, it is important to follow established criteria that differentiates this malignancy from inflammatory conditions, such as DLE.
Financial Disclosure:
No current or relevant financial relationships exist.