Granuloma formation in discoid lupus erythematosus: a novel microscopic feature

Background Lupus erythematosus is an autoimmune disease with marked pleotropism. If several systems are involved then the disease is named as systemic lupus erythematosus (SLE) and if skin is exclusively involved the term discoid lupus erythematosus (DLE) is used. One of the several histopathological features of DLE includes periappendageal inflammation. This may at times completely wipe out sebaceous glands forming sebaceous granulomas. Objective To determine the frequency of sebaceous granulomas formation in discoid lupus erythematosus. Materials and methods In this prospective observational study was conducted at the Departments of Dermatology and Pathology, Pakistan Institute of Medical Sciences, Islamabad. 100 cases of DLE spanning over two years and with the age range of 3 years to 70 years were examined for the presence of sebaceous granuloma. Other features of DLE like hyperkeratosis, follicular plugging, epidermal atrophy, basal layer vacuolization, basement membrane deposits, pigmentary incontinence, perivascular inflammation, periappendageal inflammation, and collagen damage were also noted. Results Out of these 100 cases, 8 cases contained sebaceous granulomas. These granulomas were composed of epithelioid cells, foreign body giant cells containing partially digested sebaceous material and a few lymphoctytes. Conclusion Sebaceous granulomas formation was seen in 8% cases of DLE cases. This feature must be recognized both by dermatologists and pathologist so that diagnosis of DLE may not be distracted and erroneous diagnosis due to presence of granulomas may not be rendered.