A case report of an intracardiac paraganglioma attached to the left main coronary artery in a patient with a succinate dehydrogenase complex subunit D mutation

Background

Cardiac paragangliomas are extremely rare neuroendocrine tumours derived from neural crest cells that represent <2% of all paragangliomas. Approximately 35-40% of all paragangliomas are associated with inherited syndromes such as mutation in the succinate dehydrogenase (SDH) enzyme.

Case summary

A 44-year-old male with an SDH complex subunit D (SDHD) mutation was diagnosed with an intracardiac paraganglioma attached to the left main coronary artery. Multimodality imaging, including gallium dotatate positron emission tomography computed tomography, cardiac magnetic resonance imaging, and coronary computed tomography angiography (CCTA) confirmed the suspected intracardiac paraganglioma. During follow-up with a CCTA, the mass showed growth, and surgical removal was recommended to anticipate on the risk of compression of the left main coronary artery. Prior to surgery, coronary angiography was performed, which showed no coronary calcifications. The highly vascularized paraganglioma was visible near the left main and proximal left anterior descending artery. The intracardiac paraganglioma was successfully removed through a median sternotomy with cardiopulmonary bypass, without any complications. The post-operative course was uneventful, and histological examination confirmed the diagnosis of a paraganglioma.

Discussion

Intracardiac paragangliomas in the vicinity of the left main coronary artery are rare, and surgical removal may be challenging. Therefore, screening and the use of multiple imaging modalities in patients with SDHD mutations prior to surgery is of major importance.

A family with pheochromocytoma-paraganglioma inherited tumour syndrome. Serial 18F-DOPA PET/CT investigations

AIM

Hereditary pheochromocytoma-paraganglioma syndromes are characterized by multiple pheochromocytomas (PCC) and paragangliomas (PGLs), inherited in an autosomal dominant manner. Early detection and removal of tumours may prevent or minimize complications related to mass effects and malignant transformation. Having confirmed the diagnosis, it is important to localize the tumours and reveal their extent preoperatively. This study aimed to introduce 18F-DOPA PET/CT as a highly sensitive non-invasive diagnostic tool for early detection of mass lesions in patients with pheochromocytoma-paraganglioma inherited tumour syndrome and to report about its impact on patient management.

PATIENTS, METHODS

We are currently supervising one of the largest documented families in Germany with genetically determined SDHD gene mutation. We performed 18F-DOPA PET/CT in order to detect tumours in asymptomatic gene carriers and enable subsequent surgical therapy.

RESULTS

In seven patients undergoing 12 18F-DOPA PET/CT scans 17 lesions have been detected. Three of these lesions, located in the head and neck region, have had no morphologic correlate in CT and one had also no morphologic correlate in MRI. Of the six histologically analyzed lesions five have been tumors (PGL or PCC) and one has been a nodular hyperplasia. This means the 18F-DOPA PET/CT scan in our study group had a sensitivity of 83%. 18F-DOPA PET/CT investigations lead to change in the management in 5/7 studied patients (70%).

CONCLUSION

The benefits of PET/CT in detection of pheochromocytoma and paraganglioma are well documented, but we are the first to use this technique for screening of a rare hereditary disease (estimated prevalence 0.3/100 000).

A spontaneous paraganglioma-pheochromocytoma syndrome

We present a case of a 40–year old woman diagnosed with a four–place spontaneous paraganglioma–pheochromocytoma syndrome, which was treated surgically. The presence of the succinate dehydrogenase complex subunit D (SDHD) mutation that causes the pheochromocytoma was confirmed but no mutations in the family members were found. After the excision of the paragangliomas located in the areas of the division of carotid arteries, and mediastinum, as well as a tumor on the left site of the celiac trunk, the patient remains asymptomatic and is regularly followed–up.