Diagnosing and Treating Inflammatory Myofibroblastic Tumor of the Bladder

Figure 2

(a) Hematoxylin and eosin stain of the bladder mass showing features consistent with IMT. Spindle cells and nuclear atypia are seen in a background of mixed inflammation with variable myxoid stroma. (b) ALK immunohistochemistry of the bladder mass showing cytoplasmic positivity in spindle cells. The identification of ALK suggests a neoplastic process and distinguishes IMT from other spindle cell lesions, which do not express ALK. The ALK protein is detectable in about 50% of IMTs.

(a)

(b)