Endocrine Abstracts

Introduction: Paragangliomas are neuroendocrine tumors derived from the extra-adrenal paraganglionar system and are closely related to pheochromocytoma. About 50% are associated with genetic syndromes.

Case report: We report a case of a sporadic paraganglioma incidentally found in a 30-year-old man, with no family or personal history of interest, in the context of abdominal pain study where a mass of 5×3×3 cm is detected in the abdominal aorto-cava area ultrasound. Scintigraphic study showed a focal increase of MIBG uptake in the level of anterior planes of the right paraumbilical abdominal region without any other pathological findings. Urinary cathecolamines and metanephrines were normal. A fine needle aspiration citology was made and confirmed the diagnostic of paraganglioma. Clinical study was completed with 24-hour ambulatory blood pressure monitoring, being diagnosed with arterial hypertension and starting treatment with labetalol 100 mg per day. Finally the patient underwent by right retroperitoneal lumbotomy. Histological examination revealed a paraganglioma that reaches focally the edge of the main surgical piece with no evidence of tumor in five lymph nodes. Clinical evolution was favorable with normalization of blood pressure without requiring pharmacological treatment and with negative morphological study during follow-up. Despite not having a family history of known pheochromocytoma/paraganglioma and given the age of the patient, a genetic study was performed and confirmed c.591del/p.Ser198Alafs*22 mutation in the SDHB gene. It has been described in the Mediterranean population that individuals with mutations in SDHB have a probability of developing the disease in 8, 18 and 30% at 40, 60 and 80 years respectively. Given the dominant nature of the disease, it is convenient to realize a genetic study on other relatives who are at risk of being carriers of the disorder and who do not yet know their condition. Besides, carriers of a germline mutation in SDHB have a probability around 45% of developing metastasis.

Conclusions: The genetic analysis of apparently sporadic cases reveals that up to 25% of them have a genetic mutation. Therefore, genetic screening allows early identification of the family members carrying the same mutation and carrying out the pertinent study and follow-up. In our case, despite the favorable evolution of the patient and given the greater malignant potential of this mutation, we will maintain a long-term morphological follow-up.