Clinical findings:
(1) A superficial focus may present as a palpable nodule. A deep focus may only be detectable on an imaging study.
(2) The focus may be painful and tender to palpation, especially during menstruation.
(3) The sciatic nerve or one of its branches may be involved directly or by fibrosis associated with the recurrent inflammation. This results in pain along the distribution of the affected nerve.
(4) A focus near a muscle may be painful during muscle contraction (running, jumping, etc).
Sites that may be affected:
(1) soft tissue of the thigh
(2) inguinal lymph nodes
(3) within a femoral or inguinal hernia
(4) round ligament
(5) uterosacral ligaments
(6) sciatic nerve or one of its branches
The patient may be misdiagnosed unless endometriosis is considered as a possibility. Surgical excision is often needed for the definitive diagnosis.
Differential diagnosis:
(1) incarcerated hernia
(2) nerve compression syndrome
(3) soft tissue tumor
(4) disease involving a lymph node (metastatic tumor, infection, etc)
