Successful treatment of paraganglioma with sorafenib: a case report and brief review of the literature

Pulmonary and mediastinal paragangliomas: rare endothoracic malignancies with challenging diagnosis and treatment

Background

Pulmonary and mediastinal paragangliomas are rare tumors that may have neuroendocrine activity or be non-functional, incidental, in asymptomatic patients, or causing mass effect symptoms. Although being low-grade tumors, they can display an aggressive behaviour, developing local infiltration and distant metastases. We report our experience with three endothoracic paragangliomas and a Literature review, to point out diagnostic difficulties and problems related to surgical treatment.

Methods

From 2009 to 2017, we treated 3 patients with histological diagnosis of paraganglioma: 2 pulmonary, 1 mediastinal. No one presented catecholamine-secreting syndromes; pulmonary cases were asymptomatic, while the mediastinal one had aspecific cough and dyspnea. Imaging diagnosis was based on chest computerized tomography (CT) and magnetic resonance imaging (MRI) scan. No patient had preoperative histological diagnosis. Intraoperative pathological examination was suggestive for malignancy: in pulmonary cases, wedge resection and lobectomy were performed; the middle mediastinal mass was completely removed after challenging dissection, isolation and section of numerous vascular pedicles.

Results

Postoperative course was uneventful in all cases. No patient received adjuvant treatments. At a median follow-up of 47 months (range, 6-102 months), two patients are alive, without local or distant recurrence; one patient died 6 months after surgery, due to disease progression.

Conclusions

Endothoracic paragangliomas, rare and often asymptomatic tumors, are of difficult diagnosis and should be considered malignant tumors, due to the potential aggressive behaviour of cases with high mitotic index and the frequent possibility of recurrence and metastases. Surgical resection is the treatment of choice and careful intraoperative manipulation is recommended, due to the high vascularity of these tumors, to prevent complications. After complete excision, long-term prognosis is generally good. However, even after surgical removal, a close, periodical and life-long follow-up is mandatory.

Primary Pulmonary Paraganglioma: A Case Report and Review of Literature

Primary pulmonary paraganglioma is a rare disease. We report a case of a 37-year old female patient with space-occupying lesions in the right lower pulmonary lobe during a routine examination without any symptoms. The patient underwent video-assisted thoracoscopic surgery (VATS) resection of the right middle lobe and dissection of hilar and mediastinal lymph nodes under general anesthesia. She recovered without recrudescence. Preoperative diagnosis is difficult. Accurate diagnosis requires pathological examination, and immunohistochemical test is particularly important. Complete resection is the first treatment option for solitary primary pulmonary paraganglioma; however, VATS is a better technique. Given the high local control rates and few complications of radiotherapy, it is considered as a standard treatment.

Anti-cancer potential of MAPK pathway inhibition in paragangliomas-effect of different statins on mouse pheochromocytoma cells

To date, malignant pheochromocytomas and paragangliomas (PHEOs/PGLs) cannot be effectively cured and thus novel treatment strategies are urgently needed. Lovastatin has been shown to effectively induce apoptosis in mouse PHEO cells (MPC) and the more aggressive mouse tumor tissue-derived cells (MTT), which was accompanied by decreased phosphorylation of mitogen-activated kinase (MAPK) pathway players. The MAPK pathway plays a role in numerous aggressive tumors and has been associated with a subgroup of PHEOs/PGLs, including K-RAS-, RET-, and NF1-mutated tumors. Our aim was to establish whether MAPK signaling may also play a role in aggressive, succinate dehydrogenase (SDH) B mutation-derived PHEOs/PGLs. Expression profiling and western blot analysis indicated that specific aspects of MAPK-signaling are active in SDHB PHEOs/PGLs, suggesting that inhibition by statin treatment could be beneficial. Moreover, we aimed to assess whether the anti-proliferative effect of lovastatin on MPC and MTT differed from that exerted by fluvastatin, simvastatin, atorvastatin, pravastatin, or rosuvastatin. Simvastatin and fluvastatin decreased cell proliferation most effectively and the more aggressive MTT cells appeared more sensitive in this respect. Inhibition of MAPK1 and 3 phosphorylation following treatment with fluvastatin, simvastatin, and lovastatin was confirmed by western blot. Increased levels of CASP-3 and PARP cleavage confirmed induction of apoptosis following the treatment. At a concentration low enough not to affect cell proliferation, spontaneous migration of MPC and MTT was significantly inhibited within 24 hours of treatment. In conclusion, lipophilic statins may present a promising therapeutic option for treatment of aggressive human paragangliomas by inducing apoptosis and inhibiting tumor spread.