Noradrenalin-Secreting Retroperitoneal Schwannoma Resected by Hand-Assisted Laparoscopic Surgery: Report of a Case

A 66-year-old woman was admitted to our hospital for investigation of a retroperitoneal mass. She was asymptomatic but her serum noradrenalin and vanillylmandellic acid levels were increased remarkably. Computed tomographic angiography showed a mass in the left side of the superior mesenteric artery (SMA) divergence, 6 × 4 cm in size, supplied mainly by the left adrenal artery. We performed hand-assisted laparoscopic surgery (HALS) using a Cavitron ultrasonic surgical aspirator. Abdominal exploration revealed that the tumor was located in the left side of the SMA root, but was not adhered to the adjacent organs. Her vital signs remained stable during the operation. Microscopic examination revealed a palisade formation, confirming a histopathological diagnosis of degenerated schwannoma (Antoni type B). Immunohistologically, the tumor cells were stained with S-100 protein and neuron-specific enolase. Her noradrenalin level normalized immediately after the operation and she remains in good health 3 years 2 months later.