Primary carcinoid tumor of medulla spinalis: case report and review of the literature

Cauda equina thickening: an approach to MRI findings

There are many causes of cauda equina (CE) thickening on neuroimaging of the lumbar spine. The imaging features of CE thickening for the various conditions often overlap and are non-specific to clinch a definite diagnosis. Hence, the imaging findings have to be discerned in accordance with the patient's presenting history, clinical examination findings, and results from electrophysiology and laboratory studies. In this review, the authors aim to supplement the existing literature on imaging findings of CE thickening with a diagnostic framework for clinical workup. The authors also aim to familiarise readers with the interpretation of CE thickening on magnetic resonance imaging (MRI) and would like to illustrate the normal variants and pitfalls that could be mistaken for abnormal results.

Primary Neuroendocrine Tumor of the Lumbar Spine: Rare Tumor Mimicking Nerve Sheath Tumor of the Spine

Neuroendocrine tumors (Carcinoid tumors) generally arise from enterochromaffin cells of gut and bronchi. Primary carcinoid tumors of spine are extremely rare and have been described in sacrum and coccyx. Primary carcinoid tumors involving the spinal cord are still rarer, and review of literature revealed only two cases reported. Our patient a 39-year-old male had diagnosed as a case of nerve sheath tumor (intradural extramedullary) at LV4 region on neuroimaging. However, postoperatively, the tumor turned out to be a rare primary spinal carcinoid tumor on histopathological examination and immunohistochemical staining. Work up to rule out any other site in the body was negative. To the best of our knowledge, this is the first case of primary carcinoid tumor of the lumbar spine.

Incidental Primary Intradural Carcinoid Tumor in a Patient with Lumbar Radiculopathy

BACKGROUND

Carcinoid tumors are neuroendocrine neoplasms derived from enterochromaffin cells. Central nervous system involvement is rare. The reported cases include metastases to brain or spinal cord, and primary skeletal or extradural disease resulting in compressive myeloradiculopathy. There are 2 previously reported cases of primary intradural extramedullary carcinoid tumor, presenting with compressive symptoms. We report the first case of primary incidental intradural extramedullary carcinoid tumor.

CASE DESCRIPTION

A 68-year-old man was complaining of a 2-month history of left-sided back pain and sciatica; however, he presented with acutely worse symptoms of severe left sciatica. There was no sphincter dysfunction nor power deficit on examination. A magnetic resonance imaging (MRI) scan of the lumbar spine revealed an L4-5 central disk protrusion causing left L5 nerve root compression, and a heterogeneous enhancing intradural mass at the L2-3 level displacing the cauda equina. An L4-5 microdiscectomy followed by an L2-3 laminectomy and resection of the intradural mass was performed. There was a postoperative left S1 paresthesia that was managed medically; however, the postoperative period was unremarkable. A postoperative MRI of the lumbar spine showed complete resection of the mass. A staging scan revealed an incidental thyroid nodule; however, there was no other disease burden. Histopathology of the resected specimen revealed a primary spinal carcinoid tumor.

CONCLUSIONS

To our knowledge, this is the first reported case of incidental primary intradural spinal carcinoid tumor. Even though intradural spinal carcinoid tumors are exceedingly rare, they should be included in the differential diagnosis of enhancing intradural lesions.