Pheochromocytoma is a rare catecholamine producing tumor, with a global incidence of 1-2 / 100000 inhabitants / year. Pheochromocytoma is easily characterized by the rule of tens: bilateral in 10% of cases; extra adrenal in 10% of cases; multicentric in 10% of patients; occurs in children in 10% of cases; malignant in 10% of cases. On the contrary, hereditary susceptibility is present in approximately 30-40 % of pheochromocytomas. Additionally, some genetic mutations (SDHB mutations) have been associated with a high risk of metastasis and worse survival. Extra adrenal pheochromocytoma or paraganglioma is suspected when there is a predominance of norepinephrine, since extra adrenal locations lack the ability of converting norepinephrine in epinephrine. There is no histological nor biochemical way of knowing if a pheochromocytoma is benign or malignant. Although the postoperative PASS score can give us the potential of malignancy, only the presence of distant metastasis and adjacent tissues invasion can assure malignancy of a pheochromocytoma. This means all pheochromocytomas must be treated as potentially malignant, I think.
"First 100 Thoughts" - eBook
Get your free copy now
Do not have a iOS device?
Recurrence of a pheochromocytoma is a possibility and it can occur several years after the first surgery. Recurrence rate has been reported up to 23%, while persistency of disease has been described in 3-13% of cases. Recurrence can occur in the retroperitoneum (adrenal site) and in the peritoneal cavity as peritoneal implants, the so called pheochromocytomatosis. I learned this medical term from an interesting paper publish in 2021 in Cirurgia Espanola by Dr Esther Ferrer-Inaebnit from Palma de Mallorca, Spain. The authors report a case of a young male patient submitted to a right laparoscopic adrenalectomy because of a 4cm pheochromocytoma. Nine years later the patient was once again symptomatic, and a new pheochromocytoma was diagnose in the left adrenal along with peritoneal implants in the Glisson’s hepatic capsule. Another laparoscopic adrenalectomy was conducted with peritoneal implants removal. Five years following the second operation symptoms recurred. CT scan and MRI diagnosed a retroperiotenal recurrence and several millimetric peritoneal implants, pheochromocytomatosis. Laparotomy was performed removing all identifiable implants, aiming at debulking tumor cells.
According to the authors the risk of recurrence is increased in hereditary tumors, in lesions > 5cm, and in paragangliomas. The mechanism of peritoneal disease (pheochromocytomatosis) is the intraoperative rupture of the capsule with tumor cells’ spillage. The bigger the lesion, the higher the risk of rupture. Because of this increased risk in larger pheochromocytomas, the authors highlight the accurate selection of patients for laparoscopic approach surgeons must do, in order to decrease the risk of tumor cells’ spillage within the peritoneal cavity from tumor rupture.
While reading this interesting paper, a new idea come to my mind. Retroperitoneoscopic approach can give us an advantage to avoid pheochromocytomatosis. Why? In the retroperitoneoscopic adrenalectomy the peritoneal cavity is not entered, which means that if capsule rupture and cells’ spillage occur during surgery it will only affect the retroperitoneal space. Intraperitoneal spillage of tumor cells will not be a possibility, and recurrence will be eventually limited to the Gerota’s space. So, I believe this is another advantage of retroperitoneoscopy over laparoscopy to treat adrenal tumors. Although retroperitoneoscopic adrenalectomy is limited to lesions up to 6-8 cm, inadvertent tumor rupture of lesions > 5 cm can also occur in transabdominal approach. The question is what is the consequence of tumor cells’ spillage in laparoscopy comparing to retroperitoneoscopy? Potential pheochromocytomatosis plus local recurrence versus local recurrence alone is the answer, I think.
Must not forget that surgical resection is the only way of treating a pheochromocytoma. Cytoreductive surgery for implants removal is mandatory and is the only definitive treatment, the authors say. For that, the authors talk about preoperative administration of 123I-MIBG to perform radioisotopes-guided surgery. This I have never seen but it looks interesting.
I would like to highlight two important ideas from this work. First, since a pheochromocytoma’s recurrence is possible within several years after surgery (up to 10 years), follow-up must be conducted for a long time period. Secondly, since the very beginning of classic symptoms’ recurrence (headache, diaphoresis, tachycardia) in a patient previously treated for a pheochromocytoma, genetic testing along with metanephrines testing plus a CT scan and MIBG are mandatory for metastasis diagnosis.
I am already using retroperitoneoscopic adrenalectomy as the gold standard for adrenal tumors up to 6 cm. Do you think this paper supports this idea? Well, I do!
"First 100 Thoughts" - eBook
Get your free copy now
Do not have a iOS device?
Link to article:
Dr. Carlos Eduardo Costa Almeida
General Surgeon
Comentários