Case report: Rare case of spontaneous and non-traumatic vulvar epidermoid cyst

Introduction: Epidermoid cysts are nodular structures lined with stratified squamous epithelium. In most cases, epidermoid cysts arise in the head and neck region, or in extremities, with their occurrence in the female genital tract being rare. Cases of epidermoid cysts in the female genital tract tend to have a history of trauma—mostly surgical or due to female genital tract mutilation. We present a case of biopsy proven vulvar epidermoid cyst which arose without a background of prior surgical history, female genital mutilation, or other trauma. Case Report: A 25-year-old multigravida female with two children presented with progressive painless vulvar swelling for around two years, without any history of trauma or prior surgery. Vulvar ultrasound examination revealed a well-circumscribed, ovoid subcutaneous tissue mass arising from the labia majora with internal linear echogenic and anechoic foci, as well as raised through-transmission. Magnetic resonance imaging (MRI) examination revealed an exophytic, round-to-ovoid subcutaneous mass lesion in the vulvar region which returned iso- to hyperintense signals on T1, hyperintense signals on T2-weighted images, and hyperintense signals on diffusion weighted imaging (DWI), while demonstrating a peripheral rim of enhancement on T1 post-contrast images. The patient underwent surgical excision without any complications and histopathology reaffirmed the diagnosis of vulvar epidermoid cyst having a stratified squamous epithelial lining. Conclusion: While epidermoid cysts of the female genital tract are rare occurrences in patients lacking prior surgical or traumatic history, they need to be considered as possible differential diagnoses in patients presenting with characteristic symptoms and imaging findings. Further evaluation of the clinical course and imaging findings of epidermoid cysts in the female genital tract, as well as the efficacy of different imaging modalities and interventions is essential to improve their diagnosis and management.