Papillary thyroid carcinoma occurring with undifferentiated pleomorphic sarcoma: A case report

Figure 5 Pathology result of the right nodule showing both papillary thyroid cancer and undifferentiated pleomorphic sarcoma. A: The papillary component (yellow square) grew within the pleomorphic spindle cell component (H&E, × 25); B: High-power magnification of the yellow-square area in A. In the high-power field, the papillary component showed characteristics of papillary thyroid cancer (PTC) (H&E, × 200); C: CK19 staining showed CK19-positive components (orange arrows), which suggested PTC cells, and the other CK19-negative cells were undifferentiated pleomorphic sarcoma cells (IHC, × 200).