Endocrine Abstracts

Case history: A 49-year-old male with hypertension (on doxazosin, amlodipine and perindopril), obesity (BMI 40 kg/m²) and recent DVT (on warfarin) presented with a few months’ history of episodic headaches, palpitations, light-headedness and sweats accompanied by facial pallor, occurring around twice weekly without warning. Symptoms were often worse when upright. Spontaneous recovery followed. He did not have a family history of endocrine disease. Clinical examination was unremarkable except for obesity.

Investigations: Urinary normetadrenalines were elevated on several occasions (between 9.37–21.09 umol/24h – normal <4) after stopping interfering medications. Chromogranins A and B were negative. Urinary 5HIIA and urine free cortisol were normal. CT scans did not show any adrenal or paraspinal abnormalities, but an enlarged ‘lymph node’ was demonstrated adjacent to the right seminal vesicle. Subsequent MIBG scans did not demonstrate paraspinal or adrenal abnormalities - no adrenal or extra adrenal parganglioma (PGL) was demonstrated. However, a ⁶⁸Ga-DOTATE PET scan showed a 1.8×2.6 cm paraganglioma adjacent to right seminal vesicle. Genetic analysis revealed no mutations in FH, SDHAF2, SDHB, SDHC, RET, MAX, TMEM127 or VHL genes. Following preoperative alpha blockade with phenoxybenzamine the PGL was removed through robotic surgery. Subsequent histology confirmed a benign functioning PGL. Follow up postoperative 24 urine metanephrines are awaited.

Conclusions and points of discussion: PGL of the genitourinary tract are uncommon with the bladder and urethra being most commonly affected. Seminal vesicle PGL are extremely rare with only 4 cases reported in the literature. Apart from the typical symptoms of catecholamine excess, they present with lower urinary tract symptoms, haematuria or haemospermia. As evidenced above, such lesions may be challenging to localise on standard imaging and specialised scans such as ⁶⁸Ga-DOTATATE scans may need to be utilised. Surgery remains the treatment modality of choice and robotic surgery was successful in our patient.