Fig. 2.

A 75-year-old male with previous history of renal cell carcinoma and long-standing intracranial meningioma, presented with 2-week history of vague memory loss and urinary frequency. (A) Review of H&E stained sections demonstrates a collision of a meningioma with a metastatic carcinoma composed of clear cells. (B and C) Immunohistochemistry with progesterone receptor antibodies highlights only meningioma cells with nuclear positivity. RCC antibodies highlight the clear cells of the carcinoma. These cells were also immunoreactive for cytokeratin 7 and CD10, consistent with renal cell carcinoma.