Cauda equina neuroendocrine tumour complicated by intra-tumoural hemorrhage in a young male: a case report and systematic review of the literature.

Background: Cauda equina neuroendocrine tumors (CE-NETs) are rare intradural extramedullary (IDEM) tumours that are hard to differentiate from other IDEM tumours such as schwannomas and ependymomas on imaging. While literature surrounding CE-NET and other IDEM tumours continues to grow, evidence on complications such as intra-tumoural hemorrhage remains rare, with few cases reported in the literature. Case Description: We report a rare case of intra-tumoural hemorrhage in a 35-year-old Caucasian male with newly-diagnosed CE-NET. The patient presented with acute lower back pain with L1 radiculopathy complicated by acute retention of urine. Magnetic resonance imaging (MRI) detected an IDEM mass lesion adjacent to the conus medullaris at the T12-L1 level with heterogenous enhancement. The patient underwent T12/L1 laminectomy and excision of lesion, with histology and immunohistochemical evaluation supporting the diagnosis of a well-differentiated neuroendocrine tumour. The patient made a complete recovery and was discharged on postoperative day 5. A systematic review was conducted for similar cases of intra-tumoural hemorrhage in IDEM tumours, with 36 cases of intra-tumoural hemorrhage in IDEM tumours reported to date. Conclusions: Intra-tumoural hemorrhage in IDEM tumours is rare, especially in a CE-NET tumour. While symptoms can be debilitating and range from severe back pain to significant neurologic deficit, early identification via radiological and histological evaluation as well as early surgical resection leads to good prognosis.