Cutaneous Mullerian Cyst on the Ankle: A Case Report

Cutaneous Mullerian cyst (CMC) is a rare benign cystic lesion that typically occurs on the lower extremity of young females shortly after puberty. They have been widely regarded as Mullerian heterotopias due to the morphological similarities of the cyst lining cells to the epithelium of the fallopian tubes. A 16-year-old female presented with a two-year history of a solitary, subcutaneous mass involving the left ankle. She had no specific symptoms associated with the skin lesion. However, the lesion had been growing in size. Histopathological findings revealed cystic structures lined by pseudostratified ciliated cuboidal to columnar cells, accompanying intraluminal papillary projection. The immunohistochemical staining profiles, including positive staining for estrogen and progesterone receptors, were characteristic of the fallopian tube epithelium. After being surgically removed, the lesion was cured without recurrence. Based on her typical presentation and histopathological findings, we present this patient as a case of CMC.