PMC5259666_01
Preoperative imaging findings for Case 1. (a) Contrast-enhanced computed tomography image. T1-weighted axial (b), T2-weighted axial (c), and fat-suppressed gadolinium-enhanced T1-weighted axial (d) magnetic resonance images. Computed tomography and magnetic resonance images show a soft tissue tumor with adipose tissue between the sternocleidomastoid muscle and the anterior strap muscle.
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fig1
Computed tomography (CT) scans (Figure 1(a)) revealed a 60 x 26 x 42 mm well-marginated soft tissue mass in the left lower anterior neck. On magnetic resonance imaging (MRI), the tumor exhibited soft tissue intensity with scattered high intensity that was suggestive of fat in T1-weighted images (WI) (Figure 1(b)) and T2WI (Figure 1(c)). In fat-suppressed gadolinium-enhanced T1WI (Figure 1(d)), the mass showed marked enhancement, and high-intensity areas were suppressed.
Hematoxylin and eosin (HE) staining findings in Case 1 (x40). (a) Plump to thin spindle cells with a low degree of cellular atypia can be observed. (b) Epithelial cells form anastomosing cords. (c) Intermingled adipose cells are present in the tumor.
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fig2
On histopathological examination of the resected tumor, the tumor consisted of plump to thin spindle cells growing in a bundle shape (Figure 2(a)), epithelial cells that formed anastomosing cords (Figure 2(b)), and epithelial islands with solid or microcystic extension areas. In addition, mature adipose cells (Figure 2(c)) and lymphocytes were observed between spindle cells and epithelial cells.
PMC5259666_02
Preoperative imaging findings for Case 2. (a) Contrast-enhanced computed tomography image. T1-weighted axial (b) and T2-weighted sagittal (c) magnetic resonance images. Computed tomography and magnetic resonance images show a tumor with a clear margin and intralesional adipose tissue in the left lower neck. (d) Gross findings of the tumor. The tumor was encapsulated and had a smooth external surface.
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fig3
CT scans (Figure 3(a)) revealed a 42 x 35 x 48 mm well-circumscribed mass with nonhomogeneous enhancement between the sternocleidomastoid muscle and internal jugular vein. The mass had low signal intensity similar to muscle on T1WI (Figure 3(b)) and higher intensity than muscle on T2WI (Figure 3(c)). The tumor (Figure 3(d)) was encapsulated with a smooth surface, and there was no adhesion to the surroundings.
Hematoxylin and eosin (HE) staining findings in Case 2 (x100). (a) Plump to thin spindle cells with a low degree of cellular atypia and low mitotic activity can be observed. (b) Adipose cells can be observed within the tumor.
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fig4
On histopathological examination of the resected tumor, the tumor consisted of plump to thin spindle cells growing in a bundle shape (Figure 4(a)) and adipose cells (Figure 4(b)).