PMC5444033_01
(a) Contrast-enhanced CT, (b) T1 weighted MR (c) T2 weighted MR, and (d) T1 weighted, contrast-enhanced MR. Arrows: the central part of the lesion lacks enhancement- necrotic part. Open arrows: satellite lesions are evident at the periphery of the mass.
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fig1
Subsequently, a computed tomography (CT) of his abdomen was performed, revealing a multilobulated and ill-defined, soft tissue mass, arising from the root of the mesentery, compressing the posterior wall of the stomach (Figure 1(a)). To characterize the mass further an abdominal MRI was performed, showing peripheral enhancement and a likely necrotic center, with satellite lesions evident at the periphery of the mass (Figures 1(b), 1(c), and 1(d)).
The neoplastic plasma cells showed variable degree of maturation with some of them being oval with round eccentric nucleus, "spoke wheel" chromatin, and no nucleoli, while others have prominent nucleoli or are occasional multinucleated (H-E x200).
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fig2
Mitotic figures were also apparent (Figure 2).
(a) The neoplastic cells were positive for CD138 (CD138 x200). (b) The neoplastic cells were positive for CD38 (CD38 x400).
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fig3
Immunohistochemically these cells were positive for CD138 (Figure 3(a)) and CD38 (Figure 3(b)) while CD56 was expressed in a small percentage of neoplastic cells.
The neoplastic cells showed cytoplasmic monotypic IgA and kappa-light chain restriction (kappa  x400).
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fig4
The neoplastic cells also showed cytoplasmic monotypic IgA and kappa-light chain restriction (Figure 4).