We report a case of an asymptomatic male presenting with bilateral, disseminated and well-defined pulmonary nodules. The patient had undergone resection of a retroperitoneal paraganglioma 6 years earlier; close follow-up had revealed no evidence of recurrence. After our evaluation, a VATS with wegde resection of the lingula was performed and histologic diagnosis of metastatic paraganglioma was established.
This is a 51-year-old African-American male seen in consultation for bilateral lung nodules. Six years ago he was diagnosed with an abdominal mass during a routine clinical evaluation. Subsequent imaging studies confirmed the presence of a 10x10x10cm retroperitoneal tumor between the aorta and left ureter, and resection of a 700g mass was performed. The histologic examination revealed an extra-adrenal paraganglioma with evidence of capsular and extracapsular infiltration and angiolymphatic invasion. Immunohistochemical stains for chromogranin were positive. The patient underwent radiation therapy, and follow-up octreotide scan and CT abdomen revealed no evidence of tumor activity or recurrence. Hormonal assays were negative for elevated 24-h urinary metanephrine and for serum catecholamines on two separate occasions. The patient had undergone a follow-up MRI of the abdomen 1 month before our evaluation; disseminated nodules were visualized in the liver and lung bases. His past medical history is also remarkable for chronic active hepatitis C, for which he had received treatment with interferon alfa-2b and ribavirin as well as pegylated interferon in the past 2 years; the patient has remained well compensated. He is a former smoker and has a remote history of IV drug use. At the time of our evaluation the patient was asymptomatic, and the review of systems was negative. He was normotensive, hemodynamically stable and there were no stigmata of chronic liver disease. His liver function studies and coagulation parameters were normal except for an elevated alfa-fetoprotein level of 20.8. The patient subsequently underwent VATS with wedge resection of the lingula, which confirmed the suspected diagnosis of metastatic paraganglioma. The immunohistochemical stains were positive for chromogranin and synaptophysin. As of this writing, no further intervention has been considered.
Extra-adrenal pheochromocytomas, or paragangliomas, are rare neuroendocrine tumors with infrequent pulmonary involvement. This case reveals one of the possible intrathoracic manifestations: metastatic pulmonary disease. Although most cases present with the classical paroxysmal attacks or symptoms related to catecholamine excess, our patient interestingly never exhibited any of those symptoms. We based the diagnosis on the MRI and CT scan findings, as well as on the histopathologic exam - with positive immunohistochemical markers such as synaptophysin and chromogranin. Paragangliomas are potentially malignant 40% of the time, with a mean survival of 1 to 2 years in metastatic disease. Surgical resection has been advocated in well-localized tumors. The role of radiation and combination chemotherapy has been reported to be effective in disseminated disease; however, this role is still under investigation.
Paragangliomas are tumors with infrequent intrathoracic manifestations. The related classical symptoms may be absent, and the hormonal assays may be negative as well. In such cases, we recommend basing the diagnosis on MRI and CT imaging findings, as well as on histopathologic exam with immunohistochemical markers. In addition, we believe surgery should be considered in cases involving well-demarcated lesions.
Jose Delgado, None.