The distinction of paraganglia from high-grade prostate cancer is usually straightforward in most cases. Features favoring paraganglia include: absence of benign prostate glands around them; no prominent nucleoli; nuclear atypia when present is degenerative type; and close association with nerves. In difficult cases, immunostains can be done. Neuroendocrine markers and S-100 are usually positive in paraganglion; PSA and PAP are negative. The image shows Synaptophysin immunoreactivity in a paraganglion.