A well demarcated mass is seen in the wall of the bladder (lower left corner). Note that overlying urothelium which is unremarkable.

The tumor is fairly well-delineated and quite small (0.1 cm).

At higher power, the cluster of cells have frothy cytoplasm and the nuclear details are not well-preserved, but fortunately, immunostains are extremely helpful.

Synaptophysin highlights the neoplastic cells.

Chromogranin is also quite strong.

S-100 highlights the sustentacular cells (and it looks like neoplastic cells as well).

Paragangliomas (extra-adrenal counterparts of pheochromocytomas) arises in the head and neck and the paravertebral/para-aortic region. Rarely, they can occur in unusual sites such as the bladder, heart and thyroid. Paragangliomas of the bladder account for less than 1% of all bladder tumors, and there may be association with familial paraganglioma, NF1, von Hippel-Lindau disease and Carney triad (Heinrich).

In a study of 29 patients with 39 extra-adrenal paragangliomas conducted by Sadhev (2005), the various sites included carotid body (17), mediastinum (1), cardiac (1), retroperitoneuml, extra adrenal (15), bladder (2), pelvic sidewall (2), and intra-spinal (2).

In a review of 16 paragangliomas of the bladder (span of 53 years at the Mayo Clinic), the majority occurred in adult women (mean age of 45 years) with a M:F ratio of 1:3. Most common presenting symptoms were hematuria and hypertension. The tumors were usually within the bladder wall.

Staging is an important prognostic factor with patients with at T3 or greater at risk for recurrence, metastases and death (Cheng).

→Usually develops in women in their fourth decade.

→Common presenting symptoms are dysuria, hematuria and hypertension.

• Peripheral Nervous System : Extra-Adrenal Paraganglioma