A Case of Malignant Melanoma Arising in Mediastinal Malignant Teratoma

Figure 2

Pathology of the extracted tumor: the image shows the mediastinal tumor resection tissue (19 × 13 × 11.5 cm in size). The surface is covered with a membrane, and the boundary is clear and shows expansive development. Approximately two-thirds of the cut surface show hemorrhaging and necrosis, including the cystic area of grayish white or black color. The remaining tumor tissue consists of a teratoma showing epithelial/epidermal appendages, central nerve, bone/cartilage, smooth muscle, adipose tissue, gastrointestinal epithelium, and respiratory epithelium differentiation. Mesenchymal tissue, muscle/adipose tissue, cartilage, central nervous system, and ducts can be seen as undifferentiated immature components. Several yolk sac tumor lesions showing reticular structures with positive immunostaining for alpha fetoprotein can also be seen.

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