Figure 10.

A vaginal mass is typically a soft, edematous, polypoid botryoid mass (A). Polypoid fronds of the botryoid form are typically seen on histological imaging (B). The cambium layer (subepithelial condensation of stroma) is present (C, HE × 200). The strap-shaped rhabdomyoblasts have eosinophilic cytoplasm with cross-striations (D, HE × 400) and positive nuclear staining for myoD1 (E) and myogenin (F). A giant mass (arrow) occupied the whole vaginal cavity and extended downwards to the vulva (arrowhead). The mass is mainly displayed as an isointense signal on both T ₁WI (G) and T ₂WI (H). The tiny small cysts were seen within the lesion. The tumor did show a restricted signal on DWI (I) and ADC map (J). The sagittal (K) and coronal (L) T ₂WI more clearly showed the contour of the mass. On post-contrast images (M), the tumor enhanced similarly to the normal uterus. The final pathology was RMS in a 15-year-old girl. ADC, apparent diffusion coefficient; DWI, diffusion-weighted imaging; RMS, rhabdomyosarcomas.