An Uncommon Finding of Posterior Cruciate Ligament Intrasubstance Cyst: A Case Report and Review of Literature

INTRODUCTION: Ganglion cyst of the cruciate ligaments is a rare entity. These cysts are usually found as incidental finding during knee arthroscopy, even though they can be the cause of knee discomfort or dull pain without a clear etiology. CASE PRESENTATION: We present herein a case of 35-year-old male who presented with unexplained dull knee pain. Magnetic resonance imaging (MRI) was performed and it showed a cystic-like lesion measuring 14 mm localized within the fibers of the posterior cruciate ligament (PCL) with no other significant pathology identified. A diagnosis of symptomatic PCL intrasubstance cyst was made. Patients were treated by arthroscopic debridement with good long-term outcomes. CONCLUSION: Ganglion cysts of the PCL are uncommon and especially if they were localized within the PCL fibers. MRI studies are inevitable to make the diagnosis, and arthroscopic debridement remains a reasonable surgical option with low recurrence rate.