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

Figure 1 Cervical ultrasound of the patient before surgery. A: The right-side nodule (orange arrow) was 58 mm × 41 mm × 67 mm and was classified as TI-RADS 4A; B: The left-side nodule (orange arrow) was 6.4 mm × 8 mm × 8 mm and was classified as TI-RADS 4C.

Figure 2 Cervical magnetic resonance imaging of the patient revealing an enlarged thyroid mass. A and B: Coronal and transverse magnetic resonance imaging showing that the enlarged right-sided thyroid nodule (orange arrow) pushed the trachea (blue arrow) to the left.

Figure 3 Pathological and immunohistochemical characteristics of papillary thyroid cancer. A and B: Tumor cells were arranged in a follicular pattern with enlarged nuclei and irregular nuclear membranes, indicating papillary thyroid cancer (PTC) (A: H&E, × 100; B: H&E, × 400); C: PTC cells were strongly positive for CK19 (IHC, × 200); D: PTC cells were strongly positive for TTF1 (IHC, × 200).

Figure 4 Pathological and immunohistochemical characteristics of undifferentiated pleomorphic sarcoma. A and B: Tumor cells were spindle-shaped, round, and ovoid with irregular nuclei and frequent mitoses (A: H&E, × 100; B: H&E, × 400); C: Tumor cells were strongly positive for vimentin (IHC, × 200); D: Tumor cells were negative for CK19 (IHC, × 200).

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).

Figure 6 Computed tomography of the lung metastasis. Computed tomography three months after surgery showing multiple solid nodules in both lung fields, indicating metastasis, and a larger number of and larger nodules in the left lower lobe. The largest lesion was 25 mm.