Endocrine Abstracts

Introduction: Ten per cent of pheochromocytomas are malignant. Malign pheochromocytoma could cause metastasis, relapse and local invasion. The most common sites of metastasis for pheochromocytoma or extra-adrenal paraganglioma are lymph nodes, bones, lungs, and liver. Here, we present a case who had pheochromocytoma relapse and unusual peritoneal metastasis after 12 years of left adrenalectomy.

Case presentation: A 38 year-old woman, who had left adrenalectomy due to malignant pheochromocytoma in 2006, was admitted to outpatient clinic for routine visit. Her physical examination was normal. In the blood tests, ACTH level was 29,1 pg/ml and cortisol level was 14 ug/dl. In 24-hour urine tests, the hormone levels were as defined: free cortisol: 60 nmol/g (N: 38–208), metanephrine: 3469 μg (N: 276–341), normetanephrine 8199 μg (N: 88–444). In the abdominal MRI, there was a solid mass of 50×86×55 mm in the right adrenal gland on and left adrenal gland region findings were compatible with adrenalectomy. An operation was offered, but she came for the operation after 5 months. Pre-operative CT showed a relapse or residual mass of 25×20 mm, suspicious features for renal capsular invasion and multiple nodules suspicious for malignant implants in the adipose tissues of subhepatic, right paracolic, bilateral pelvic and left retroperitoneal regions. There was also a solid mass of 85×53×53 mm in the right adrenal gland region. Cortex sparing adrenalectomy on the right side, left adrenal glandresidual mass excision, omentectomy and appendectomy were performed. Multiple tumor implants scattered in the abdomen were also resected. The pathological findings of all surgery materials exhibited metastatic pheochromocytoma. Postoperative ACTH stimulation test indicated adrenal gland IN sufficiency. Hence, hydrocortisone was added to the treatment. Genetic tests demonstrated heterozygous RET mutation c.1891G>T(p.Asp631Tyr).

Conclusion: Pheochromocytomas may occur in large sizes and metastasize. The standard treatment of malignant pheochromocytoma is excision of the tumor. Despite to radical excision, relapse in chromaffin tumors and metasynchronous tumor development may evolve. Close follow up of the patient is mandatory.

Keywords: bilateral, pheochromocytoma, peritoneal metastasis