Calcium pyrophosphate deposition disease of the temporomandibular joint invading the middle cranial fossa: Two case reports

Figure 4 Histopathology of Case 1 and Case 2. A: There are crystal deposits (black arrows) in the fibrous tissue. The crystal deposits are surrounded by foreign body type giant cells and fibroblasts (hematoxylin-eosin staining, × 100; Case 1); B: Crystalline material (orange arrows) deposits exhibiting birefringence under polarized light (hematoxylin-eosin staining, × 100; Case 1); C: Nodular clusters of calcium pyrophosphate dihydrate crystals (black arrows) could be seen (hematoxylin-eosin staining, × 200; Case 2); D: Crystals of different shapes with strong stereoscopic effect (hematoxylin-eosin staining, × 400; Case 2).