Papillary thyroid carcinoma with nodular fasciitis-like stroma - an unusual variant with distinctive histopathology: A case report

Figure 1 Neck ultrasonography. A and B: Ultrasonography image of the neck showed a mixed echoic and horizontal nodule measuring approximately 5.1 cm × 3.1 cm × 2.9 cm in the left thyroid gland; C and D: Fine needle aspiration revealed a mass of hyperplastic glandular epithelial cells and infiltration of short spindle cells.

Figure 2 Histopathological features of papillary thyroid carcinoma with nodular fasciitis-like stroma. A: The papillary tumor consisted of extensive stromal proliferation and classical papillary thyroid carcinoma cells; B: The stromal part of spindle cells showed vigorous proliferation of myoblasts, lymphocytes infiltration and exudated red blood cells; C: Lymphocytic infiltration was also seen around the tumor stroma.

Figure 3 Immunohistochemical features of papillary thyroid carcinoma with nodular fasciitis-like stroma. A: The epithelial component showed significant positive expression of thyroid transcription factor-1, and Galectin-3; B: The stromal spindle cells in the tumor demonstrated prominent cytoplasmic staining with smooth muscle actin and CD34; C: Significant β-catenin staining was also found in nuclear and cytoplasmic regions. The Ki-67 proliferation index was < 3% both in the epithelial and stromal components.