A Pararectal Epidermal Cyst, as an Internal Compressive Factor in a Case of Lichen Sclerosus et Atrophicus

Lichen sclerosus et atrophicus (LSA) is a disorder of unknown etiology, although factors as varied as hormonal influence, genetic predisposition, autoimmunity, or infection, have been proposed as causes of the disease. Today, it is generally accepted that, whatever the etiology, the common pathogenetic process is inflammatory. We present the case of a 42-year-old woman in whom hormonal status was found to be normal. The clinical history did not show any antecedents of the disease in her family; HLA-DQ7 was not present in the patient; no autoantibodies were found, and her blood-sugar level as well as her hormonal profile were normal. Contrary to the absence of these commonly admitted causes related to LSA, the presence of a mechanically associated factor was remarkable: An epidermal cyst, 8 cm in diameter, appeared to be compressing the perineal region. Knowing that it could be just a mere coincidental tumor, we evaluated the hypothesis of the mechanical factor in the development of LSA.