| Domain | High-confidence quantitative finding/recommendation | Evidence type/year | Key source DOI or PMID where available |
|---|---|---|---|
| Epidemiology / heredity | PPGLs are rare neuroendocrine tumors; ~80–85% arise in adrenal medulla and ~15–20% are extra-adrenal paragangliomas; hereditary contribution is commonly ~30–40% overall (pqac-00000001, pqac-00000007) | Peer-reviewed reviews, 2023–2024 | 10.3389/fendo.2024.1433582; 10.1530/JME-22-0167 |
| Molecular classification | Three major molecular clusters: pseudohypoxia (cluster 1), kinase signaling (cluster 2), and Wnt-signaling / MAML3-CSDE1-associated cluster 3 (pqac-00000001, pqac-00000007, pqac-00000023) | Peer-reviewed reviews, 2023–2024 | 10.3389/fendo.2024.1433582; 10.1530/JME-22-0167 |
| Major susceptibility genes | >20 driver/susceptibility genes reported; commonly cited genes include SDHA/B/C/D, SDHAF2, VHL, RET, NF1, TMEM127, MAX, FH, MDH2, SLC25A11, DLST, EPAS1/EGLN-related genes (pqac-00000007, pqac-00000023) | Peer-reviewed review, 2023; scoping review, 2024 | 10.1530/JME-22-0167; 10.3389/fendo.2024.1433582 |
| Phenotypes / symptom frequencies | Classic symptoms/signs are variable; one 2024 scoping review summarized hypertension 92%, sustained hypertension 48%, paroxysmal hypertension 44%, headache 59%, palpitations 50%, diaphoresis 50%, dizziness 67%, orthostatic hypotension 12% (pqac-00000020) | Scoping review, 2024 | 10.3389/fendo.2024.1433582 |
| Biochemical diagnosis | Plasma free metanephrines: sensitivity ~96%, specificity ~85%; suggested highly indicative thresholds in one review were normetanephrine >2.5 pmol/mL or metanephrine >1.4 pmol/mL; supine sampling after ≥30 min recumbency is recommended to reduce false positives (pqac-00000023) | Scoping review, 2024 | 10.3389/fendo.2024.1433582 |
| Urinary diagnosis | 24-hour urinary catecholamines/metanephrines: sensitivity ~87.5%, specificity ~99.7%; urinary metanephrine/creatinine linkage can improve accuracy (pqac-00000023) | Scoping review, 2024 | 10.3389/fendo.2024.1433582 |
| Adjunct biochemical marker | Plasma 3-methoxytyramine is recommended with metanephrines as a first-line biochemical marker set, especially relevant for dopamine/SDH-related biology (pqac-00000008, pqac-00000013) | Peer-reviewed review, 2020 | 10.1093/hmg/ddaa201 |
| Clonidine suppression | For distinguishing false-positive norepinephrine elevations, clonidine suppression test reported sensitivity 97% and specificity 100%; <50% fall in plasma norepinephrine after clonidine is abnormal (pqac-00000020) | Scoping review, 2024 | 10.3389/fendo.2024.1433582 |
| Anatomic imaging | CT abdomen/pelvis is typical first localization test after biochemical evidence; CT sensitivity reported as 88% and accuracy 90–95% for tumors >1.3 cm in one review (pqac-00000020) | Scoping review, 2024 | 10.3389/fendo.2024.1433582 |
| Functional imaging detection rates | 68Ga-DOTA-SST PET/CT detection ~93% (95% CI 91–95) as first-line functional imaging in one review; 18F-DOPA PET/CT ~80% (95% CI 69–88) in hereditary cluster 2; 18F-FDG PET/CT ~74% (95% CI 46–91) as alternative (pqac-00000009, pqac-00000018) | Scoping review, 2024 | 10.3389/fendo.2024.1433582 |
| Genotype-specific imaging guidance | SDHx-related tumors: [68Ga]-DOTA-SSA PET/CT favored; VHL- and many kinase-cluster tumors: [18F]FDOPA PET/CT often most sensitive; [123I]MIBG sensitivity ~50–75% overall and <50% in SDHB-associated tumors (pqac-00000002) | Review, 2024 | 10.3390/biomedicines12102385 |
| Genetic testing strategy | Germline testing is recommended for all PPGL patients; targeted NGS panels are described as current gold standard, rather than sequential gene-by-gene testing (pqac-00000015, pqac-00000018) | Peer-reviewed review, 2023; scoping review, 2024 | 10.1530/JME-22-0167; 10.3389/fendo.2024.1433582 |
| IHC / pathology support | Loss of SDHB staining is a useful screening/prognostic biomarker for SDHx-related disease; SDHA-, MAX-, and FH-related IHC can support variant interpretation; histopathology alone cannot diagnose malignancy, which requires metastasis (pqac-00000008, pqac-00000015, pqac-00000018) | Reviews, 2020–2024 | 10.1093/hmg/ddaa201; 10.1530/JME-22-0167; 10.3389/fendo.2024.1433582 |
| Inheritance / penetrance example: SDHD | SDHD shows autosomal dominant inheritance modified by maternal imprinting; penetrance reported as 86% by age 50; tumors are mainly head-and-neck, with thoraco-abdominal PGL up to 22% and PCC 12–24% (pqac-00000016) | Peer-reviewed review, 2023 | 10.1530/JME-22-0167 |
| Inheritance / penetrance example: SDHB | SDHB mutations occur in ~8–10% of PPGL; penetrance reported as ~30% by age 80 in one review; associated with thoraco-abdominal PGLs, H&N PGLs, and PCCs, with higher metastatic concern (pqac-00000014, pqac-00000016) | Peer-reviewed review, 2023 | 10.1530/JME-22-0167 |
| Inheritance / penetrance example: SDHA | SDHA pathogenic variants can be found in up to ~10% of PPGL in cited review datasets, with low penetrance estimated around 10% by age 70 and often apparently sporadic presentation (pqac-00000016) | Peer-reviewed review, 2023 | 10.1530/JME-22-0167 |
| Syndrome example: VHL | ~20% of VHL patients develop PCC/PGL; VHL-related PPGL are often multifocal/bilateral (43–45%), metastatic in <5%, and median diagnosis age ~29 years (pqac-00000016) | Peer-reviewed review, 2023 | 10.1530/JME-22-0167 |
| Syndrome example: MEN2 / RET | ~50% of MEN2 patients develop PCC; 50–80% of MEN2-associated PCCs are bilateral; only a small percentage metastasize (pqac-00000017) | Peer-reviewed review, 2023 | 10.1530/JME-22-0167 |
| Syndrome example: NF1 | Estimated 0.1–5.7% of NF1 patients develop PPGL (3.3–13% in autopsy studies); NF1-associated PPGL are usually unilateral and metastasize up to ~10% (pqac-00000017) | Peer-reviewed review, 2023 | 10.1530/JME-22-0167 |
| Syndrome example: MAX | MAX germline review of 109 carriers reported mean diagnosis age 32.8 years, bilateral PCC in 59/101 PCC cases, metastasis in 19/101 (~18.8%), and male:female ratio 1.3:1 (pqac-00000000) | Aggregated case series/review, 2024 | 10.3389/fendo.2024.1442691 |
| Metastatic-risk markers | Independent correlates of metastatic risk reported in review include SDHB mutation plus norepinephrine/dopamine biochemical phenotype; larger size, extra-adrenal location, and cluster-1 biology are recurrent risk signals (pqac-00000003, pqac-00000018) | Reviews, 2024 | 10.3390/biomedicines12102385; 10.3389/fendo.2024.1433582 |
| Aggressive disease biomarkers | Somatic ATRX alterations, TERT activation, and MAML3 fusions are associated with aggressive/metastatic behavior; MAML3 rearranged tumors had metastases in 37.5% in one cited review summary (pqac-00000008, pqac-00000015) | Reviews/pre-existing primary data synthesis | 10.1093/hmg/ddaa201; 10.1530/JME-22-0167 |
| Surgery | Minimally invasive/laparoscopic resection is generally suitable for most pheochromocytomas <5 cm; open surgery/lymph-node dissection may be preferred for larger, invasive, extra-adrenal, synchronous metastatic, or SDHB-associated tumors (pqac-00000018) | Scoping review, 2024 | 10.3389/fendo.2024.1433582 |
| Perioperative blockade | Endocrine Society-based preparation: alpha-blockade first; phenoxybenzamine start 10 mg orally twice daily and titrate up to 1 mg/kg/day, or doxazosin; beta-blocker added 3–4 days later if needed; increased salt/water intake 10–14 days pre-op (pqac-00000018) | Scoping review/guideline-based summary, 2024 | 10.3389/fendo.2024.1433582 |
| Metastatic radionuclide therapy: HSA-I-131-MIBG | FDA-approved in 2018 for metastatic PPGL; response rate ~30–40% in review summary; phase II multicenter trial of 68 patients: 25% had durable antihypertensive-medication reduction, 92% achieved partial response or stable disease within 12 months, median OS 36.7 months (95% CI 29.9–49.1) (pqac-00000009, pqac-00000018) | Phase II trial summarized in 2024 review | 10.3389/fendo.2024.1433582 |
| Real-world MIBG outcome | Real-world study of 24 metastatic PPGL patients reported 38% objective response rate, 83% disease control rate, BP normalization in 56%, but notable grade 3–4 myelosuppression and one fatal pneumonitis (pqac-00000021) | Real-world study summarized in review, 2024 | 10.3389/fendo.2024.1433582 |
| Chemotherapy | Conventional chemotherapy response is ~37% overall in review summary; complete responses are uncommon; temozolomide may be especially relevant in SDHB/MGMT-methylated disease (pqac-00000021) | Review, 2024 | 10.3389/fendo.2024.1433582 |
| TKIs / targeted therapy | Sunitinib small studies showed disease control ~57–83% and median PFS ~4–13 months; FIRSTMAPP phase II reported 12-month PFS 36% on sunitinib vs 19% placebo; cabozantinib phase II ORR 25.0% (4/16 responders); axitinib phase II partial response 36% (pqac-00000021, pqac-00000024) | Phase II and review summaries, 2024 | 10.3389/fendo.2024.1433582 |
| Surveillance | For metastatic PPGL, CT/MRI every 3–6 months in first year, then every 6–12 months if stable; secretory disease should have plasma free or 24-h urinary fractionated metanephrines at least every 6 months (pqac-00000018, pqac-00000010) | Review/guideline summaries, 2023–2024 | 10.3389/fendo.2024.1433582; 10.1016/S2213-8587(23)00038-4 |
| Pediatric disease | Pediatric PPGL accounts for ~10–20% of all PPGL; annual incidence ~0.5–2.0 per million children; median presentation age 11–15 years; hereditary background in ~70–80% (pqac-00000004) | International consensus statement, 2024 | 10.17863/cam.111911 |
| Pediatric metastatic management | In pediatric metastatic PPGL, surgery is the only curative therapy; about 50% of treatment-naive patients may show stable disease at 1 year; radionuclide therapy is considered for avid tumors without rapid progression (pqac-00000006) | International consensus statement, 2024 | 10.17863/cam.111911 |
| Recent single-cell findings | A 2024 preprint scRNA-seq study of 16 tissues from 5 PCC patients identified “metabolism-type” (NDUFA4L2/COX4I2) and “kinase-type” (RET/PNMT) tumors, with distinct immune microenvironments and potential therapeutic implications; this is preprint-level evidence (pqac-00000000) | Preprint, 2024 | 10.1101/2023.03.26.534245 |
| Recent multi-omics findings | A 2024 preprint multi-omic analysis of 94 SDHB-deficient tumors from 79 patients linked TERT and ATRX alterations with metastatic disease, increased mutation load, and treatment-related profiles including MGMT overexpression/MMR deficiency; preprint-level evidence (pqac-00000000) | Preprint, 2024 | 10.21203/rs.3.rs-4410500/v1 |
| Active recent trials | Examples from ClinicalTrials.gov search: NCT07714551 zanzalintinib phase II not yet recruiting (n=14); NCT07282587 ONC206 phase II recruiting (n=90); NCT03206060 Lu-177-DOTATATE phase II recruiting (n=130); NCT07680205 belzutifan impact on catecholamine metabolism phase II recruiting (n=12); NCT06429397 anlotinib + benmelstobart phase II not yet recruiting (n=22) (pqac-00000000) | ClinicalTrials.gov records, current at retrieval | NCT07714551; NCT07282587; NCT03206060; NCT07680205; NCT06429397 |
| Evidence gaps | Limited high-level evidence for environmental/protective factors and gene–environment interactions; limited validated QoL datasets in retrieved evidence; no robust protective genetic variants established; comparative veterinary disease/model-system evidence was not substantively captured in retrieved contexts; several omics findings are from preprints and need peer-reviewed validation (pqac-00000024, pqac-00000025) | Evidence-gap summary from retrieved set | 10.3389/fendo.2024.1433582; 10.1530/JME-22-0167 |


*Table: This table compiles compact, knowledge-base–ready evidence on pheochromocytoma and paraganglioma across clinical, genetic, diagnostic, and treatment domains. It prioritizes quantitative findings and recent sources, while flagging areas where evidence remains sparse or preprint-only.*