A resected case of liver metastases from extra-adrenal retroperitoneal paraganglioma with von Recklinghausen's disease 16 years after the initial surgery.

The patient was a 46-year-old man who had undergone resection for a bulky retroperitoneal tumor 16 years previously during a follow-up for von Recklinghausen's disease. Histopathological examination of the resected specimen showed that the tumor was an extra-adrenal paraganglioma. After the surgery, he had survived without any recurrence of the tumor. However, 16 years after the initial surgery, liver tumors were identified, and he was referred to our hospital for further investigation and treatment. Abdominal imaging modalities showed three masses in the left lateral segment of the liver. Fluorodeoxyglucose-positron emission tomography/computed tomography showed an abnormal uptake of fluorodeoxyglucose corresponding to the mass lesions. The patient was diagnosed with a metastatic paraganglioma based on histopathological examination of a liver mass biopsy. The patient underwent left lateral sectionectomy of the liver. Histopathological examination of the resected specimen revealed proliferating cells with basophilic cytoplasm and oval densely stained nuclei arranged in an alveolar pattern, which was similar to the findings of the initial resection specimen. Immunohistochemical staining was positive for synaptophysin and chromogranin A. Based on these findings, the resected tumors were histopathologically diagnosed with liver metastases from the retroperitoneal paraganglioma. We concluded that this is an extremely rare case of liver metastases occurring long after the initial resection of extra-adrenal peritoneal paraganglioma with von Recklinghausen's disease.