Cutaneous endometriosis: diagnostic immunohistochemistry and clinicopathologic correlation.

Endometriosis is a condition where endometrial glands and stroma are ectopically located in sites other than the uterine cavity. Cutaneous endometriosis is very rare, representing approximately 1.1% of cases of extrapelvic endometriosis. We report a case of a 44-year-old female with no prior surgical history who presented with multiple tan brown periumbilical nodules. Histopathological examination revealed multiple glandular structures in the dermis with surrounding stroma. Immunohistochemistry cinches the diagnosis, as CD10, estrogen receptor and progesterone receptor are strongly positive in our case. The mainstay of treatment of cutaneous endometriosis is surgical excision of the lesion.