Successful treatment of a giant ossified benign mesenteric schwannoma

Figure 1 Computed tomography findings. A: In a native CT scan, the mass in the upper left abdomen appeared well defined (green arrow), while regions of high density were visible (red arrow); B: On the contrast-enhanced CT, the mass was inhomogeneous and slightly enhanced, and regions of high density were also visible (green arrow). CT: Computed tomography.

Figure 2 Magnetic resonance imaging findings. A: On MRI, the mass (white arrow) in the upper left abdominal cavity appeared hypointense on T1-weighted images; B: The mass (white arrow) appeared inhomogeneous hyperintense on T2-weighted images. MRI: Magnetic resonance imaging.

Figure 3 Microscopic examination. A: Microscopically, in the mesenteric tumour, both hypercellular and hypocellular areas were visible. The tumour mainly consisted of spindle-shaped cells with a palisading arrangement; atypical cells or signs of malignancy were not observed (HE × 40); B: Some areas of the tumour were ossified, and a true metaplastic bone formation could be seen, with the presence of bone lamellae and osteoblasts (HE × 200). HE: Hematoxylin and eosin.

Figure 4 Immunohistochemical staining. The mesenteric tumour was strongly positive for S-100 (× 40).