Potential Anatomical Implications of Filum Terminale Paraganglioma on Coccygodynia: A Case Report

Abstract

In this case report, we present a unique cause of coccygodynia due to an intradural lumbar spinal tumour in a patient with multiple filum terminale paragangliomas. We highlight the symptomatology, the clinical course, and the radiological findings. Our review of the literature proved our case to be the first report of an intradural cauda equina tumour presenting with coccygodynia in English literature. Based on the outcome and clinical response to treatment we make a bold hypothesis on the possible anatomical mechanism of his coccygodynia.

Keywords: coccygodynia; filum terminale; intradural tumor; paraganglioma; spinal tumor.

Figure 1. Sagittal T1 Gd+ MRI of the lumbar spine

Sagittal T1 Gd+ MRI of the lumbar spine showing two intradural cauda equina tumours, a larger one at the L3 level (big arrow) and a smaller one at the S2 level (small arrow).

Figure 2. Sagittal T1 Gd+ MRI of the same patient

Sagittal T1 Gd+ MRI of the same patient disclosed abnormal, serpiginous vessels between the tumour at L3 and the conus medullaris (arrow). This represents a typical sign of filum terminale paragangliomas.

Figure 3. Axial T1 Gd+ MRI

Axial T1 Gd+ MRI above the superior end of the tumour shows a large intrathecal vessel that continues rostrally (arrow), indicative of a hypervascular lesion.

Figure 4. Sagittal post-operative T1 Gd+ MRI

Sagittal post-operative T1 Gd+ MRI showing complete removal of the tumour at L3 (grey arrow) and increase in the size of the smaller one at S2 (red arrow), at the time of patient’s coccygodynia relapse.

Figure 5. Schematic drawing of the intrathecal topographic organization of the cauda equina nerve roots at L2/L3 and L3/L4 levels.

Hatch circle represents the approximate location of the filum terminale tumor. The drawing is based on the monumental human cadaveric study by Wall et al. (1990) [13]