A Silent Interval with Aggressive Return: Metastatic SDHB-Mutated Mediastinal Paraganglioma
https://doi.org/10.15605/jafes.041.S1
- Author:
Seetha Devi Subramanian
1
;
Nor Shaffinaz Yusoff Azmi Merican
1
;
Shartiyah Ismail
1
Author Information
1. Endocrinology Unit, Department of Medicine, Hospital Sultanah Bahiyah
- Publication Type:Journal Article
- MeSH:
Paraganglioma
- From:
Journal of the ASEAN Federation of Endocrine Societies
2026;41(S1):86-87
- CountryPhilippines
- Language:English
-
Abstract:
Introduction:Mediastinal paragangliomas (PGLs) are extremely rare
extra-adrenal neuroendocrine tumors, accounting for
approximately 2% of all PGLs and commonly associated
with pathogenic germline variants (PGVs), particularly
those involving succinate dehydrogenase (SDH) mutations.
Case:We report a 35-year-old female presenting with chronic
cough and hemoptysis, accompanied by paroxysmal
symptoms and new-onset hypertension. She had a history
of pheochromocytoma treated 15 years earlier with right
adrenalectomy and liver lobectomy due to intraoperative
adrenal adherence to the liver. Histopathology confirmed
adrenal pheochromocytoma, with no evidence of PGL in the
liver. She remained in biochemical remission for 3 years but
subsequently defaulted. Biochemical evaluation revealed
markedly elevated 24-hour urinary normetanephrine
(58,950 nmol/L; ~26-fold increase). Computed tomography
of the thorax demonstrated a mediastinal mass compressing
the right bronchus, resulting in luminal narrowing and
segmental lung collapse. Endobronchial biopsy confirmed
PGL (Ki-67 index 5%). Functional imaging with DOTATATE,
FDG-PET, and MIBG demonstrated metastatic disease
involving the lungs and lymph nodes. Genetic testing
identified a heterozygous pathogenic SDHB mutation
(c.79C>T; p.Arg27), consistent with autosomal dominant
hereditary PGL-pheochromocytoma syndrome; family
screening confirmed the same mutation in her father and
two siblings. She underwent two sessions of bronchoscopic
intervention, including cryoablation, balloon dilation, argon
plasma coagulation, and intratumoral alcohol injection
for airway control and hemoptysis. Multidisciplinary
evaluation deemed complete surgical resection high risk
and not feasible; therefore, peptide receptor radionuclide
therapy was initiated.
Conclusion:This case demonstrates the aggressive and metastatic
nature of SDHB-mutated PGLs. This group of patients
require long term surveillance given the risk of developing
new tumors even years or decades after primary tumor
resection. It highlights the importance of genetic testing
following pheochromocytoma surgery to guide targeted
therapy, lifelong surveillance, and family screening within
a multidisciplinary care approach.
- Full text:2026080414302020213EP_A121.pdf
