PMC6091335_01
Grayscale (a) and color Doppler (b) sonographic imaging demonstrates a fusiform, heterogeneously hypoechoic mass in the posterior left neck, adjacent to the paraspinal muscle, without significant increased vascularity.
CRIPE2018-1243436.001.jpg
PMC6091335_01_CRIPE2018-1243436.001.jpg
fig1
An ultrasound at six days of life demonstrated a solid, ovoid, heterogeneously hypoechoic mass in the posterior left neck, adjacent to the paraspinal muscle measuring 3.2 x 1.4 x 2.1 cm (Figure 1).
PMC6091335_02
(a) Axial STIR image shows areas of increased T2 signal in the rounded masses within the right and left paraspinal muscles (rectangle). (b) Axial T1 postcontrast image shows mild enhancement within the rounded masses (circle).
CRIPE2018-1243436.002.jpg
PMC6091335_02_CRIPE2018-1243436.002.jpg
fig2
Axial diffusion-weighted imaging (DWI) demonstrates areas of rounded restricted diffusion in the posterior left and right paraspinal muscles of the neck (arrows).
CRIPE2018-1243436.003.jpg
PMC6091335_02_CRIPE2018-1243436.003.jpg
fig3
(a, b) H&E stain at medium magnification show both discrete nodules of spindle cells (a) as well as individual spindle cells infiltrating among variably atrophic skeletal muscle fibers and collagenized stroma (b). Mitoses were conspicuous, and there was no anaplasia or significant pleomorphism. (c, d) Immunohistochemistry stains demonstrate scattered nuclear positivity with myogenin (c) and strong cytoplasmic positivity with desmin in a majority of cells (d). The Ki-67 proliferative index was around 40%.
CRIPE2018-1243436.004.jpg
PMC6091335_02_CRIPE2018-1243436.004.jpg
fig4
Microscopy revealed a spindle cell and sclerosing rhabdomyosarcoma (Figure 4).