Intractable hiccups: a rare presentation of phrenic nerve schwannoma.

INTRODUCTION: Schwannoma rarely involves the phrenic nerve. We report a unique case of schwannoma as a cause of chronic hiccups due to the involvement of phrenic nerve. CASE
PRESENTATION: A 72-year-old male presented with 20-year history of hiccups. He underwent multiple esophagogastroduodenoscopy procedures, all of which were negative. A computed tomography (CT-scan) of soft tissue of the neck was remarkable for left retrosternal mass with central calcification, located adjacent to the thyroid gland. He underwent surgery and this mass was found to be originating from the left phrenic nerve. Resection of the portion of phrenic nerve with mass was performed. Grossly, the specimen was a pale-tan piece of soft tissue, 4.8 cm in maximum dimension with an attached portion of nerve. Microscopically, it showed a well-circumscribed spindle cell lesion with hypercellular and hypocellular areas and multiple Verocay bodies. There was no atypia or significant mitotic activity. On immunohistochemical staining, the spindle cells were positive for S-100, supporting the diagnosis of schwannoma.
CONCLUSION: Postoperatively, the patient showed marked improvement in his symptoms and the hiccups were almost completely resolved. Although they are very rare, schwannomas of the phrenic nerve should be considered in the differential diagnosis of chronic hiccups.