Endocrine Abstracts

JOINT2080

Introduction: Takotsubo cardiomyopathy is a rare presentation of pheochromocytomas and paragangliomas (PPGLs) and it is associated with a higher degree of morbidity and mortality. In this report, we present a patient with PCC-induced Takotsubo cardiomyopathy with rare SDHA and EGLN1 variants.

Case Presentation: A previously healthy 17-year-old woman with no cardiovascular risk factors was admitted to a cardiac intensive care unit due to dyspnea, chest pain and elevated blood pressure at 210/100 mmHg. In addition, the patient gave an 8-month history of paroxysmal hypertension, headache and diaphoresis. Serum troponin levels were elevated and ECG and heart ultrasound findings were indicative of Takotsubo cardiomyopathy with an ejection fraction of 20-25%. She was treated with a combination of bisoprolol, sacubitril/valsartan, empagliflozin, eplerenone, furosemide and doxazosine. An abdominal MRI revealed a 55 mm heterogenous left adrenal lesion with high T2 signal and no signal suppression on out-of-phase T1-weighted images. 24-h urine normetanephrine levels were elevated [1926 μg/24h (<669)] whereas 24h urine metanephrine levels were normal [67 μg (<276)]. Whole-body MIBG scintigraphy revealed selective radiotracer uptake by the adrenal lesion. A diagnosis of pheochromocytoma was made and the patient underwent an uneventful laparoscopic left adrenalectomy 3 weeks later. Histology confirmed the diagnosis of pheochromocytoma with a PASS score of 8 and a Ki-67 of 3-4%. Genetic testing with whole exome sequencing identified the missense SDHA variant, c.1367C>T, resulting in replacement of serine by leukine at codon 456, p.Ser456Leu, of SDHA protein and the frameshift EGLN1 variant, (c.1163_1166del).

Conclusion: Catecholamine-induced cardiomyopathy is an uncommon feature of pheochromocytoma. SDHA-related PPGLs, account for up to 2.8% of cases and are usually found in the head and neck region or the abdomen, with only 15% of them being pheochromocytomas. Although our patient’s SDHA variant is considered of uncertain significance, it has been reported in a case of SDH-deficient GIST and received a cancer-like functional classification in a recent study using a novel human SDHA-knockout cell line model. Furthermore, our patient has a previously unreported variant of EGLN1, which is another susceptibility gene for PPGLs. Further studies are needed to determine whether these gene variants are pathogenic and whether they act synergistically for PPGL development.