Diagnostic Imaging and Treatment of a Left Atrial Paraganglioma

Advanced imaging of cardiac Paraganglioma: A systematic review

Background and aims

Cardiac ParaGangliomas (PGLs) are rare extra-adrenal tumours that arise from chromaffin cells of the sympathetic ganglia. PGL are often diagnosed incidentally, with no symptoms or symptoms related to cardiovascular dysfunction.

Methods

Cardiac Computed Tomography (CCT) and Cardiac Magnetic Resonance (CMR) can detect the correct morphology and position of the lesion and provide proper tissue characterization.Nuclear medicine imaging, with Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) with specific radiotracers, can evaluate the functionality of the PGL and to distinguish a secreting from a non-secreting tumour.

Results

In association with biochemical parameters, a multimodal imaging approach, not yet standardized, can be useful both in the diagnosis, in the monitoring and in the treatment planning.

Conclusions

In this systematic review, we aim to investigate the role of diagnostic imaging, in particular CCT, CMR, PET and SPECT in diagnosis, characterization and monitoring of cardiac PGLs.

Multimodality Imaging Evaluation of Primary Right Atrial Paraganglioma: A Case Report and Literature Review

Background

Cardiac paraganglioma (CPGL) accounts for 1–3% of cardiac tumors and is usually benign. In total, 35–50% of CPGL lesions secrete catecholamines, causing hypertension, excessive sweating, palpitations, headache, and other symptoms. Preoperative imaging evaluation is important to determine the location of the cardiac mass, its blood supply vessels, and the relationship with surrounding structures. Multimodal imaging techniques combine with morphological and functional information to provide powerful methods for preoperative diagnosis and lesion localization. Furthermore, they can assist to reduce the incidence of intraoperative and postoperative complications and improve patient prognosis.

Case Report

A 67-year-old woman suffered from paroxysmal palpitations with a heart rate of 110 beats per minute 1 month ago. Urine catecholamine and methoxyepinephrine levels were significantly increased. The patient had a 5-year history of hypertension with a maximum blood pressure of 160/100 mmHg. Computed tomography (CT) examination found a soft tissue mass in the right atrium with heterogeneous and significant enhancement, whose blood supply was from the left ileal branch artery. The patient then underwent cardiac magnetic resonance (CMR). The lesion showed inhomogeneous iso signals on the T1-weighted image (T1WI), slightly high signals on the T2 fat-suppression image, inhomogeneous high signals on the diffusion-weighted imaging (DWI), and apparent diffusion coefficient (ADC) images. The mass exhibited heterogeneous and significant enhancement on the first perfusion and delayed scans after intravenous contrast injection. However, abnormal signals were surprisingly found in the patient’s right lung, and the possibility of metastatic lesions could not be excluded. The patient underwent F-18 fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG PET/CT) to rule out metastatic lesions. A fluorodeoxyglucose (FDG)-avid soft tissue mass was shown in the right atrium, with the maximum standardized uptake value (SUVmax) at about 15.2, as well as a pathological intake of brown fat throughout the body. Combined with clinical symptoms, CPGL was considered without significant sign of metastasis in 18F-FDG PET/CT. Finally, the patient underwent surgical resection and the post-operative pathology confirmed a CPGL.

Conclusion

The combination of 18F-FDG PET/CT with the CMR containing different image acquisition sequences provides a powerful aid for preoperative non-invasive diagnosis, localization, and staging of CPGL, which helps to reduce intraoperative and postoperative complications and improve patient prognosis.

Cardiac paragangliomas: A case series with clinicopathologic features and succinate dehydrogenase B immunostaining

Cardiac paragangliomas (PGs) are very rare tumors that comprise less than 1% of all cardiac tumors. PGs can occur sporadically, but inherited syndromes may also play a role in the development of PGs. Approximately one-third of PGs are associated with mutations in the succinate dehydrogenase (SDH) complex, specifically SDHB, as part of syndrome-associated PGs or sporadic PGs. SDH mutations have been assessed by SDHB immunohistochemistry, as negative staining indicates a high likelihood of mutation in PGs in other sites, but not in cardiac PGs. This study aims to evaluate the clinical and pathologic characteristic of cardiac PG cases and assess the expression of SDHB by immunohistochemistry. A retrospective chart analysis of 10 patients with cardiac PG was performed to assess the patient age, sex, size, site of the tumor, and clinical symptoms. Histologically the tumors showed the classic pattern of nested tumor cells surrounded by sustentacular cells. Immunohistochemistry for SDHB was performed in five cases. One case showed a complete absence of SDHB immunohistochemical staining and the others showed staining ranging from a weak-to-strong granular cytoplasmic staining pattern. We conclude that SDHB immunostaining is cost-effective in identifying cases with SDH mutation. It is recommended to assess SDH mutation in patients with cardiac PG to predict the aggressive behavior that has been reported by previous studies from PGs of other sites.