case_images: PMC2627170_01
case_images: A 49-year-old female patient with a palpable mass in her left breast. Mammography demonstrates a high-density mass with irregular shaped, measuring 2.3 cm, without calcification in the upper outer quadrant of the left breast.
case_images: kjr-9-80-g001.jpg
case_images: PMC2627170_01_kjr-9-80-g001.jpg
case_images: F1
case_images: Mammography showed a high-density mass, 2.3 cm, with irregular shaped in the left upper outer breast (Fig. 1).
case_images: Ultrasound (A) of her left breast shows a hypoechoic mass, 2.6-cm, with irregular shaped, located in the junction of the breast parenchyma and the subcutaneous fat layer. Color Doppler ultrasound (B) shows increased vascularity within the mass.
case_images: kjr-9-80-g002.jpg
case_images: PMC2627170_01_kjr-9-80-g002.jpg
case_images: F2
case_images: On ultrasound (US), a hypoechoic mass, 2.6 cm, with irregular shaped was noted in the junction of the breast parenchyma and the subcutaneous fat layer (Fig. 2A). US showed increased vascularity within the mass (Fig. 2B). US-guided core needle biopsy and surgical excision showed a metastatic thymoma of the B3 type.
case_images: Photomicrograph (A) discloses lobular growth of the oval to polygonal cells that are separated by dense fibrous stroma (Hematoxylin & Eosin staining, x100). Immunohistochemical staining (B) demonstrates the presence of thymocytes in the tumor cell nests (CD99, x100).
case_images: kjr-9-80-g003.jpg
case_images: PMC2627170_01_kjr-9-80-g003.jpg
case_images: F3
case_images: The nests were admixed with a minor component of lymphocytes, resulting in a lobular sheet-like growth of the neoplastic epithelial cells (Fig. 3A). On immunohistochemistry staining, the tumor cells were positive for CK (AE1/AE3) and CD99, and TdT-positive thymocytes were found in the tumor cell nests (Fig. 3B).