Tumor de células gigantes de la bursa de la pata de ganso (bursitis villonodular pigmentada extraarticular): a propósito de un caso / Giant cell tumor of the pes anserine bursa (extraarticular pigmented villonodular bursitis): a case report

Resumen: La sinovitis villonodular pigmentada extraarticular, también llamada tumor de células gigantes de la vaina tendinosa, es frecuente en la mano, siendo extremadamente rara su localización en la rodilla. Se presenta el caso de un paciente con una bursitis villonodular pigmentada de la bursa de la pata de ganso sin afectación intraarticular. Extra-articular pigmented villonodular synovitis, also called giant cell tumor of the tendon sheath, is common in the hand, being extremely rare in the knee. We present the case of a patient with a pigmented villonodular bursitis of the pes anserine bursa without intraarticular involvement.

Abstract: Extra-articular pigmented villonodular synovitis, also called giant cell tumor of the tendon seath, is common in the hand, being extremely rare in the knee. We present the case of a patient with a pigmented villonodular bursitis of the pes anserine bursa without intraarticular involvement.

Sonoanatomic Variation of Pes Anserine Bursa

BACKGROUND: The pes anserine bursa lies beneath the pes anserine tendon, which is the insertional tendon of the sartorius, gracilis, and semitendinosus muscles on the medial side of the tibia, but it can lie in different sites in the medial knee. Accurate diagnosis of the position of the bursa is critical for diagnostic and therapeutic goals. The aim of this study was to evaluate sonoanatomic variations of the pes anserine bursa in the medial knee. METHODS: One hundred seventy asymptomatic volunteers were enrolled in this study. Using ultrasound imaging (transverse approach, 7-13 MHz linear array probe) the sonoanatomic position of the pes anserine bursa and its relation to the pes anserine tendon were evaluated. Additionally, we evaluated the sonoanatomic variation of the saphenous nerve. RESULTS: The position of the pes anserine bursa was between the medial collateral ligament and the pes anserine tendons in 21.2%/18.8% (males/females) of subjects; between the pes anserine tendons and the tibia in 67.1%/64.7% (m/f); and among the pes anserine tendons in 8.2%/12.9% (m/f). No significant differences in the position of the bursa existed between males and females. The saphenous nerve was found within the pes anserine tendons in 77.6%/74.1% (m/f) of subjects, but outside the pes anserine tendons in 18.8%/15.3% (m/f). Visibility of sonoanatomic structures was not related to either gender or BMI. CONCLUSIONS: Ultrasound provides very accurate information about variations in the pes anserine bursa and the saphenous nerve. This suggests that our proposed ultrasound method can be a reliable guide to facilitate approaches to the medial knee for diagnostic and therapeutic objectives.