Figure 3.

Unequivocal progression of unmeasurable disease according to the RECIST 1.1 criteria. (a)T1-weighted axial MRI of a patient with renal cell carcinoma demonstrates a small metastasis in the marrow cavity of the distal phalanx of the left great toe (arrow). Bone disease without a soft tissue mass ≥ 10 mm is considered unmeasurable disease under RECIST 1.1. (b) Eight months later, the metastasis has markedly enlarged, representing unequivocal progression of unmeasurable disease. (c) A frontal radiograph of the foot demonstrates complete cortical lysis of the distal phalanx. The toenail is evident (arrowhead). Periarticular osteopenia is likely secondary to disuse.