Objective: To document a rare case of endometriosis in the soleus and gastrocnemius muscles.
Design: Case report.
Setting: Tertiary care center.
Patient(s): A 30-year-old fertile woman presented with moderate dysmenorrhea associated with calf pain and bulging that had been gradually worsening over the last years, particularly during menses. A mass in the soleus and gastrocnemius muscles was identified in ultrasonography and magnetic resonance imaging.
Intervention(s): Endometriosis was diagnosed by incisional biopsy on the basis of histopathology, and wide excisional biopsy was performed.
Main outcome measure(s): Unusual clinical presentation of endometriosis.
Result(s): The patient was disease free for 2 months. Recurrence of the lesion was then diagnosed, and a new surgical approach was planned.
Conclusion(s): Endometriosis in muscles is a rare event, and existing theories are not totally sufficient in explaining it.