Transverse colon foreign body-associated reactive mass mimicking gastrointestinal stromal tumors: A case report

Figure 4 Histopathological features of the subserosal cystic lesion with foreign-body reaction A: Low-power microscopic examination demonstrates a thick fibrous cystic wall in the subserosa, filled with necrotic materials. Cholesterol crystals (arrow) with an accompanying foreign-body reaction are noted; B: High-power magnification of the cyst wall reveals dense fibrosis with mild chronic inflammatory cell infiltration. The cystic cavity contains numerous macrophages, amorphous necrotic debris with cholesterol crystals (arrow); C: Periodic Acid-Schiff staining of the intracystic contents highlights irregularly shaped foreign materials (arrow).