Malignant paraganglioma of the urinary bladder: Immunohistochemical study of prognostic indicators.

Using various immunohistochemical markers, the objective of our study was to assess whether correlation exists between growth potential of paraganglioma (pheochromocytoma) cells and formation of metastasis. The patient was a 28-yr-old man who presented with intermittent episodes of gross hematuria due to a mass in the urinary bladder. He had no constitutional symptoms to suggest paraganglioma. Histologic, immunohistochemical, and electron microscopic investigation of the surgically removed tissue proved that the tumor was a malignant paraganglioma with metastases in the regional lymph nodes. The immunohistochemical tests were not supportive of high cell proliferation index, indicating that metastases can develop in the absence of rapid multiplication of the tumor cells. Abnormalities in vascular architecture and marked expression of VEGF in the tumor cells may be regarded as prognostic signs to predict the formation of metastases.