Endocrine Abstracts

Introduction: Pheochromocytomas are adrenomedullary catecholamine-secreting tumors. These account for <0.1% of all causes of hypertension and may be related to potentially fatal hypertensive crises. Can appear as sporadic tumors or associated with familial syndromes.

Malignancy occurs in 15–20% of the cases and is characterized by local invasion or distant metastasis rather than capsular invasion. Tumor recurrence has been reported with a frequency between 6 and 23% wherein the highest rate of recurrence is usually associated with familial syndromes.

Case report: A 48-year-old woman was investigated at General Surgery Department in 2011 referring severe headaches refractory to analgesic therapy, episodic postural hypertension and palpitations. Initial investigation identified a nodular lesion of left adrenal gland with 3.5 cm major axis and catecholamine hypersecretion so left adrenalectomy was performed. First histopathological study was compatible with pheochromocytoma probably with benign behavior.

At April 2015, the patient started to complain again of palpitations and was referred to the Endocrinology Department. Abdominal CT was performed showing remaining glandular tissue in surgical loci. Elevated catecholamines on urinary samples (metanephrines 1572.76 μg/24 h (normal range (NR) 0–350); normetanephrines 1681.68 μg/24 h (NR 0–600); Vanillylmandelic acid 13.60 mg/24 h (NR 1–13.6)) were also demonstrated. 123I-MIBG scan showed and abnormal uptake in the left adrenal loci and the patient went surgical reintervention 1 month later. Second histopathological study reaffirmed the presence of pheochromocytoma – score 10 PASS classification by Thompson; pTNM: rT3; R1. The tumor demonstrated positive immunoreactivity for chromogranin and synaptophysin and the Ki-67 index was <2%.

CT and 123I-MIBG scan performed 2 months later confirmed a persistent lesion on the left adrenal loci and secondary lesions in left subdiaphragmatic topography; plasma and 24-hour free catecholamine remain elevated.

According to these findings, the patient was proposed for second surgical re-intervention with block excision of tumor mass, spleen, perirenal fat, parietal peritoneum and left diaphragmatic crus in August 2015. Third histopathological study showed none metastatic invasion in four lymphnodes and no tumoral infiltration on parietal peritoneum; R0 margin was confirmed.

Last laboratory findings showed near normal plasma Metanephrines (61.4 pg/ml; NR <60) and plasma Normetanephrines (124.4 pg/ml; NR <120); normal Vanillylmandelic acid (3.99 mg/24 h; NR <7), normal urinary Normetanephrines 484 μg/24 h (NR 50–650) and lower urinary Metanephrines (557.65 μg/24 h; NR 30–350).

Post second surgical re-intervention 123-I MIBG showed no abnormal uptake on left adrenal loci and low uptake area in left sub diaphragmatic which did not justify additional therapy.

Since the patient remains asymptomatic with favorable laboratorial evolution and no further therapy was recommended in multidisciplinary decision, it was decided to maintain clinical, analytical and imagiological surveillance.

Genetic analysis did not confirm any clinically relevant mutation in SDHAF2, SDHB, SDHC, SDHD, MAX, TMEM127 and VHL genes.

Conclusions: Pheochromocytoma is a rare tumor and patients with localized disease can develop a recurrence in 6–23% of the cases, usually 5 to 15 years after initial surgery.

Near 50% of patients with recurrent disease experience distant metastasis, so, long-term follow-up is essential for all patients with pheochromocytoma even when initial pathology is not suspicious of malignancy.