juxta-articular myxoma

Juxta-articular myxoma is essentially morphologically identical to cellular myxoma but involves subsynovial tissue, usually of larger joints, and may quite often recur locally.

References

 The evolving classification of soft tissue tumours: an update based on the new WHO classification. Fletcher CD. Histopathology. 2006 Jan;48(1):3-12. PMID: 16359532