Synchronous metastatic seminoma and primary retroperitoneal ganglioneuroma: case report and literature review

A RETROPERITONEAL SEMINOMA WITH ENTRAPPED NERVE GANGLION MASQUERADING AS A PARAGANGLIOMA

Objective

The differential diagnosis of retroperito-neal tumors includes lymphoid, germ cell, and neurogenic tumors such as paraganglioma. Paragangliomas are rare neuroendocrine tumors of the autonomic nervous system, which may secrete catecholamines and their metabolites. Clinical features include sustained or paroxysmal hypertension, headaches, sweating, and palpitations. Here we present an unusual case of a retroperitoneal tumor entrapping a sympathetic nerve ganglion and mimicking paraganglioma.

Methods

A 57-year-old man with a history of controlled hypertension presented with paroxysms of tachycardia, flushing, high blood pressure, and headache. Ambulatory blood pressure monitoring showed uncontrolled labile hypertension with a normal nocturnal dip. Abdominal computed tomography (CT) demonstrated a 6.1 cm mass in the right retroperitoneum with adjacent lymphadenopathy. Paraganglioma was suspected and 24-hour urine demonstrated elevated normetanephrines (575 mcg/24 hours; normal, 5 to 290 mcg/24 hours) and vanillylmandelic acid (8.3 mg/24 hours; normal, 0.5 to 6.6 mg/24 hours). 68-Gallium DOTATATE positron emission tomography/CT showed weak uptake in the retroperitoneal mass and no other mass lesions.

Results

Following preparation with alpha-adrenergic blockers, surgical excision was performed with diagnostic and curative intent. Postoperatively, hypertension and paroxysmal symptoms resolved completely. The histopathology report described seminoma with an entrapped large ganglion within the tumor.

Conclusion

We describe a retroperitoneal seminoma with an entrapped ganglion causing hypertension and paroxysmal symptoms, with laboratory and imaging features compatible with paraganglioma. Awareness of the rare possibility of mechanical pressure on a ganglion, within the differential diagnosis of retroperitoneal mass and sympathetic symptoms may aid in clinical decision making in atypical cases.

Post-orchidectomy retroperitoneal seminoma: A case report

Between 2 and 5% of malignant germ cell tumors in males arise at extragonadal sites. The origin of extragonadal retroperitoneal germ cell tumors remains controversial. Whether these develop primarily in the retroperitoneum or are metastases of a primary testicular tumor has long been debated. We report a 38-year-old male who presented with abdominal pain and was diagnosed with retroperitoneal seminoma. The patient gave a history of having undergone a right orchidectomy for an undescended testis via the inguinal route 10 years previously with a reported histology of benign inflammatory mass.