Peritoneal Inclusion Cysts Presenting as a Femoral Hernia: A Case Report.

Peritoneal inclusion cysts (PICs) are rare benign mesothelial cystic proliferations, typically occurring in women with prior abdominopelvic pathology. We report a case of a woman in her 70s presenting with an irreducible groin mass, found to have a concurrent fatty indirect inguinal hernia and femoral hernia containing multiloculated PICs in the absence of known risk factors, including prior abdominopelvic surgery or inflammation. Preoperative ultrasound suggested a hydrocoele of the canal of Nuck.  Intraoperative exploration revealed a multiloculated cystic lesion within the femoral canal containing straw-coloured fluid without internal communication. The lesion was excised, and histopathology confirmed PICs without malignancy.  This case highlights an atypical presentation of PICs in an older patient without predisposing factors and demonstrates the potential for diagnostic misinterpretation on imaging. Clinicians should consider PICs as a differential in cystic groin masses, even in the absence of typical risk factors.