PMC9178976_01
(a) Post-contrast dorsal view (matrix 512 x 512, window level 76 HU, window width 372 HU, field of view adjusted to patient size, patient in sternal recumbency) showing a large rounded well-encapsulated, hypodense mass arising from the left pancreatic lobe. Craniolateral displacement of the spleen (orange arrow) and the liver (yellow arrow) was noted. (b) Post-contrast transverse view (matrix 512 x 512, window level 76 HU, window width 372 HU, field of view adjusted to patient size, patient in sternal recumbency) showing a large, rounded, well-encapsulated, hypodense mass arising from the left pancreatic lobe. Lateral displacement of the spleen (yellow arrow) was noted
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The remainder of the mass was hypodense and fluid filled (Figure 1).
A population of slender spindle cells (black arrow) was revealed by cytology. Magnification x100
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However, an inflamed mesenchymal neoplasm could not be ruled out (Figure 2).
Intraoperative photograph showing the large pancreatic mass within the omental bursa; the greater and lesser omentum adhered to the mass. The distal left pancreatic limb was present (black arrow)
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Exploration revealed a large multilocular cystic mass within the mid-distal portion of the left limb of the pancreas (Figure 3).
(a) Low (x0.5 magnification) and (b) high-power (x40 magnification) view of the spindle cell population. Areas of cavitation and necrosis are seen (black arrow)
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There were some admixed lymphocytes and plasma cells throughout, and areas of necrosis filled with fibrin and red blood cells, with some accompanying macrophages displaying erythrophagocytosis (Figure 4).
Positive cytoplasmic staining with (a) desmin and (b) smooth muscle actin (both x40 magnification)
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Desmin, M0760, 1:100) and actin: (Dako Monoclonal Mouse, Anti-Human Smooth Muscle Actin, Clone 1A4, M0851, 1:400). Desmin (smooth and striated muscle) and smooth muscle actin (smooth muscle) staining revealed a widespread moderate-to-strong cytoplasmic labelling of the proliferating cellular population (Figure 5).