Paragangliomas (PGLs) are rare neuroendocrine tumours derived from the autonomic nervous system paraganglia. We present a 28-year-old woman diagnosed with a large inoperable mediastinal PGL after presenting with persistent postpartum hypertension. She had four pregnancies each complicated by hypertension and pre-eclampsia, the last requiring emergency caesarean section and intensive care to control refractory hypertension and pre-eclampsia. Nine months later she was investigated for persistent hypertension associated with 20kg weight loss, lethargy and spells of diaphoresis and palpitations. Family history was notable for PGL in both her father and paternal grandmother. Subsequent investigation found markedly elevated urinary normetanephrine 16,382 nmol/d (NR 600-3300) and dopamine 16,407 nmol/d (NR 375-3500). CT showed a 6-cm posterior mediastinal mass with avid uptake on 68Ga DOTATATE PET/CT and left atrial wall involvement on cardiac MRI. There was no evidence of metastases or other tumours. Phenoxybenzamine was commenced. At thoracotomy the mass was inoperable as it invaded the left atrial wall. Biopsy confirmed PGL and immunohistochemistry staining for succinate dehydrogenase B (SDHB) was negative consistent with a high likelihood of a SDH subunit germline mutation. She is now undergoing radionuclide therapy, 177Lutetium Octreotate (Lutate) and remains on phenoxybenzamine and metoprolol.
Most PGLs are diagnosed in the third to fifth decade1,2, almost half are associated with an inherited syndrome3,4, and about one quarter of catecholamine-secreting PGLs are malignant4. Surgical resection is the mainstay of treatment. One third of resected PGLs recur within five years5. External beam radiotherapy, radionuclide and chemotherapies may be used alone or in combination for inoperable or malignant disease. Hereditary PGL due to SDH deficiency is associated with poorer prognosis compared with other mutations with younger age of onset and higher malignancy rates (21 – 79%)6,7. This case highlights the importance of investigating persistent postpartum hypertension, and recognising the classic symptoms of catecholamine secreting tumours.