FIG 3. Images in a third patient with a solid cerebellar tumor that progressed to enlarging cyst with the subsequent development of symptoms.

A, Contrast-enhanced T1-weighted MR image obtained at presentation shows a tiny enhancing nodule in the left cerebellar hemisphere (arrow). (400/8 [TR/TE])

B, Image acquired 19 months later demonstrates a tiny cyst adjacent to this tumor. (300/9)

C, A T2-weighted image obtained 24 months after the initial study shows that the cyst has enlarged. It continued to increase in size, as demonstrated on a CT scan (not shown) obtained 3 months later. Shortly after this examination, surgical excision was performed. (3720/91.5)