A Case of Rheumatoid Arthritis Complicated by Compression of the Popliteal Artery and Tibial Nerve Due to an Organized Hematoma in the Popliteal Fossa: A Case Report and Literature Review.

BACKGROUND/OBJECTIVES: Among the various types of masses that can cause compression, hematomas are a relatively common but often overlooked cause. Rheumatoid arthritis (RA) is associated with bleeding problems due to vascular inflammation, platelet dysfunction, impaired production of clotting factors, and medication use.

CASE PRESENTATION: We report a case of a 76-year-old woman with RA who developed vascular and neurological symptoms in her right lower leg due to compression of the popliteal artery and tibial nerve by an organized hematoma in the popliteal fossa. She experienced swelling, pain, and plantar flexor weakness in the affected leg with no history of trauma. Magnetic resonance imaging revealed a mass measuring 1.2 × 1.0 × 3.0 cm in size in the right popliteal fossa that was in contact with the popliteal artery and tibial nerve on its posterolateral aspect. Electrodiagnostic examination revealed that the right tibial neuropathy developed most probably around the knee level. Surgical excision of the hematoma resulted in almost complete resolution of symptoms, and excisional biopsy disclosed findings of an organized hematoma. We confirmed that the patient's symptoms were induced by compression of the popliteal artery and tibial nerve due to the organized hematoma in the right popliteal fossa.

CONCLUSIONS: This case report emphasizes the importance of considering space-occupying lesions, such as organized hematomas, in patients with RA who develop neurological and vascular symptoms.