Have oval mass left psoas muscle 28.3mm x 17.3mm, nov 2019 was 23.1mm x 15.0mm. 3 pet scans from 12/ 2019-5/2020. all glowed like xmas tree. removed a lymph node from my neck, results inconclusive. has webbing. any thoughts? uniquepf@hotmail.com?

I would think that a conclusive diagnosis of the mass is necessary at this stage and a biopsy would be the way to go. Good Luck

I would be concerned about a slowly growing malignancy such as sarcoma. Has any of your MD's recommended a biopsy in view of the hot pictures on pet scan? Perhaps you should seek another opinion at an orthopedic department in a university hospital near you.

At this point in time a biopsy would be the next reasonable step to identify the mass. Have you seen an oncologist?