Clinicopathological features analysis of Paraganglioma of urinary bladder: A retrospective study

Abstract

Paraganglioma of urinary bladder (PUB) is a rare neuroendocrine neoplasm. This study is a retrospective analysis of clinicopathological features in 11 cases of PUB. The studied cohort included seven male and four female patients with a median age of 64 years (range 37–73 years). The maximum tumor diameter ranged from 1 to 4 cm (median: 2.5 cm). Macroscopically, most lesions appeared as smooth, polypoid intraluminal protrusions; one case exhibited a nodular mass extending into the outer bladder wall. Microscopic evaluation demonstrated tumor infiltration into the muscularis propria (6 cases) or both lamina propria and muscularis propria (5 cases). Tumor cells were arranged in nested (Zellballen) or organoid patterns. Tumor cells uniformly expressed CD56, synaptophysin, and chromogranin. The Ki-67 proliferation index was ≤8 % in 10 cases; one case with a 4 cm tumor demonstrated a higher Ki-67 index (20 %), correlating with infiltrative growth and increased mitotic activity. Among the 10 cases that were evaluated, 2 (20 %) showed a loss of SDHB expression; Eight (80 %) of 10 cases were GATA3-positive, and all cases were negative for OCT3/4. Nine (81.8 %) underwent transurethral resection of bladder tumor, and 2 (18.2 %) underwent partial cystectomy. Intraoperative blood pressure fluctuations were observed in 2 patients (18.2 %). The median follow-up time was 26 months (range 4–73 months); one patient experienced a recurrence of endometrial cancer 4 years later and was lost to follow-up at 73 months; the remaining 10 patients survived without recurrence or metastasis. Improved preoperative recognition of PUBs relies on integrating clinical, biochemical, and imaging findings. Standardized immunohistochemical panels may enhance diagnostic accuracy.