PMC10126605_01
Radiological, pathological, and molecular features of parotid ALES. (a) CT scan showing an ill-defined mass in the right parotid gland. (b) Hematoxylin and eosin staining showing monotonous small round cells grew in cords and nests with monomorphic nuclei (magnification: x20). (c) IHC demonstrating strong and homogeneous membranous CD99 positivity (magnification: x20). (d) FISH showing rearrangements of EWSR1 and FLI1. Arrow 1: intact EWSR1 allele; arrow 2: 5'EWSR1 fused 3'FLI1; 3: derivative 3'EWSR1; 4: FLI1 non-translocated allele. (e) Chromosome 22q and 11q map showing the specific binding sequence areas for the 5'EWSR1 probe (spectrum orange), 3'EWSR1 probe (spectrum green) and 3'FLI1 (spectrum aqua).. FISH, fluorescence in situ hybridization; IHC, immunohistochemistry.
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PMC10126605_01_10.1177_17588359231165979-fig1.jpg
fig1-17588359231165979
Contrast-enhanced computed tomography (CT) of the face and neck revealed an ill-defined mass measuring 19 x 22 x 23 mm in the right parotid gland infiltrating the homolateral masseter muscle (Figure 1(a)). Microscopically, the tumor consisted of monotonous small round cells grew in cords and nests containing monomorphic nuclei and infiltrating skeletal muscle structures (Figure 1(b)).