Endocrine Abstracts

Introduction: The mutation of SDHB gene is associated with familial pheochromocytoma-paraganglioma syndrome (PPS). SDHB gene is located in locus 1p23–25 and encodes a subunit B of succinate dehydrogenase, which plays a key role in the respiratory chain and Krebs cycle.

Pheochromocytoma in PPS usually produces norepinephrin. Even long term remission do not exclude relapse of the disease.

We present a case of bilateral adrenal pheochromocytoma due to familial pheochromocytoma-paraganglioma syndrome associated with SDHB mutation.

Case report: At the patient’s age of 18 the first diagnosis of pheochromocytoma associated with typical clinical symptoms was made and followed by uncomplicated left adrenal gland tumor enucleation.

Seventeen years later during a follow up examination the right adrenal gland pheochromocytoma was suspected. The clinical manifestation, MIBG scintigraphy and metanephrine and katecholamine level results confirmed the presence of pheochromocytoma. Right adrenalectomy was performed without complication. The histopathological exam again revealed pheochromocytoma.

One year later the abnormal level of katecholamine and metanephrine in urine collection was revealed followed by raised tracer uptake in MIBG scintigraphy within left adrenal gland. Somatostatin analogues scintigraphy did not confirmed the lesion.

Due to the medical history of the patient left adrenalectomy was performed. The histopathological examination reveal normal adrenal gland tissue.

At the same time genetic testing (PCR) revealed the mutation of SDHB gene. The other members of the patient’s family were healthy without presence of SDHB mutation.

By now the katecholamine and metanephrine concentration in urine collection and MIBG scintigraphy are normal.

Conclusion: The biochemical and imaging follow up should be perform for an extend period of time after surgery in a case of SDHB mutation. MIBG should be done in case of abnormal biochemical results. Genetic testing should be perform in any case of pheochromocytoma relapse, especially among young patients. The patient’s family members should undergo genetic testing as well.