An Uncommon Presentation of Carcinosarcoma of the Stomach and a Minimally Invasive Approach for Treatment

Figure 3

Microscopic pathology of the tumor. (a–d) Microscopic images of a fungating polyp. (a) Sheets of squamous cells displayed malignant features including large cell size and keratinization, providing evidence of squamous-cell carcinoma at 10x magnification. (b) The tumor arose in the background of a fundic gland polyp at 4x magnification. (c) Regions of the tumor and the entire lymph node metastasis displayed osteosarcomatous differentiation, evidenced by osteoid (pink) and associated atypical enlarged spindled cells at 20x magnification. (d) Evidence of both adenocarcinoma (left) and osteosarcoma (right) in the same fungating polyp tissue at 10x magnification. (e, f) AE1/AE3 staining. (e) Sarcomatous tissue of the tumor stained negative for AE1/AE3 seen at 20x magnification. (f) Adenocarcinoma component of the main tumor stained positive for AE1/AE3 imaged at 10x magnification. (g) Osteosarcoma component of the main tumor stained negative for AE1/AE3 at 10x magnification. (h) The squamous-cell carcinoma component was positive for P40 seen at 10x magnification. (i) The undifferentiated pleomorphic sarcoma was focally CD138 positive imaged at 20x magnification. (j) Beta-hCG was negative in giant cells, ruling out a choriocarcinoma component, seen at 20x magnification. (k) The undifferentiated pleomorphic sarcoma with osteoclast-like giant cells component was diffusely vimentin positive, seen at 10x magnification. (l) The osteosarcoma component of tumor was vimentin positive, imaged at 10x magnification.

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