Fig. 9.

Urinary bladder paraganglioma with an underlying SDHB mutation detected through immunohistochemistry. A Routine hematoxylin–eosin stain of a urinary bladder paraganglioma arising in a young female patient. B SDHB immunohistochemistry revealing absent tumor staining, while adjacent sustentacular cells and stromal components were positive. This staining pattern is highly indicative of an underlying SDHx gene mutation. C The SDHA immunostaining was positive, as indicated by a granular, cytoplasmic signal. D Regional lymph node exhibiting synchronous metastatic deposits. Clinical genetics counseling was initiated, and the patient was found to harbor a germline SDHB mutation