Evidence Review
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Meta-Anal. Oct 28, 2020; 8(5): 375-382
Published online Oct 28, 2020. doi: 10.13105/wjma.v8.i5.375
Current trend in the diagnosis and management of malignant pheochromocytoma: Clinical and prognostic factors
Ayun K Cassell III, Abdoul Halim Bague
Ayun K Cassell III, Department of Urology and Andrology, Hopital General de Grand Yoff, Dakar 3270, Senegal
Abdoul Halim Bague, Unit of Surgical Oncology, Department of General Surgery, Yalgado Ouedraogo Teaching Hospital, Ouagadougou 160, Burkina Faso
Author contributions: All authors have made considerable contributions to conception and design, collection of data, analysis and interpretation of data, were involved in preparing the article or revising it methodically for essential intellectual content, gave final approval of the version to be published, and agree to be liable for all aspects of the work.
Conflict-of-interest statement: The authors declare having no conflicts of interest regarding this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Ayun K Cassell III, FICS, MD, MSc, Academic Fellow, Lecturer, Senior Researcher, Surgeon, Department of Urology and Andrology, Hopital General de Grand Yoff, Grand Yoff, Dakar 3270, Senegal. ayuncasselliii@gmail.com
Received: October 7, 2020
Peer-review started: October 7, 2020
First decision: October 22, 2020
Revised: October 26, 2020
Accepted: October 27, 2020
Article in press: October 27, 2020
Published online: October 28, 2020
Abstract

Pheochromocytomas are tumors arising from the chromaffin cell of the adrenal gland and paragangliomas as tumors from extra-adrenal sympathetic chromaffin cells. The combined yearly incidence of pheochromocytoma and paraganglioma (PPGL) is approximately 0.8 per 100000 person/year. Malignant pheochro-mocytoma is defined only by the presence of metastasis, as there is no confirmatory histology or biomarkers. The most common metastatic sites of these chromaffin tumors are the lymph node, bone, lungs, and liver. This review focuses on relevant clinical and immunohistological factors that are predictive of malignant PPGL or metastasis and determinants of prognosis. Findings showed that the risk of malignant PPGL, along with disease survival, is closely associated with age, primary tumor size, gender, synchronous metastasis, and absence of surgical excision. Other essential biomarkers or immunohistology investigated were galectin-3, COX-2, nm-23, microRNA-210, ERBB-2 overexpression and succinate dehydrogenase subunit mutation, which were predictive of malignancy as well as disease prognosis. Curative resection is possible but most metastatic diseases are amenable to radiopharmaceuticals and chemotherapy due to late presentation. Other therapeutic options, like molecular-targeted therapy, are still undergoing clinical trials.

Keywords: Chromaffin, Malignancy, Metastatic, Paraganglioma, Pheochromocytoma, Prognosis

Core Tip: The diagnosis of malignant pheochromocytoma/paraganglioma (PPGL) is challenging. To date, confirmatory histology and biomarkers are still lacking. Data from recent studies have shown various biomarkers and genetic mutations that are predictive of malignancy, metastasis and disease prognosis of PPGL, but primary tumor size, male sex and synchronous metastasis have revealed consistent association with malignant PPGL and its prognostication.