Case report
A 52-year-old man with a one-year history of low back pain, presented with worsening pain accompanied by new onset bilateral lower extremity paraesthesia, gait disturbance and dermatomal pain (L2-L3 dermatomes).
Workup with spinal MRI detected an intradural filum terminal lesion. No other detectable suspicious lesions were present. The patient was referenced for neurosurgery with a clinical and imagiological suspicion of ependymoma.
Surgery with L5 and S1-S2 posterior laminectomy and complete excision of suspect lesion was performed. Progressive clinical resolution of the low back pain and neurological symptoms.
Pathological report described adenocarcinoma cells with papillary and trabecular pattern. Immunohistochemically positive for AE1/AE3, CAM 5.2, synaptophysin and negative for cytokeratin 7 and 20, EMA, TTF1, PSA, S100 and GFAP.
The histopathologically characteristics were compatible with metastasis of adenocarcinoma with neuroendocrine differentiation.
The patient underwent post-operative radiotherapy from L4- to S3 (45Gy in 18 fractions).
Investigative work up for primary neuroendocrine carcinoma with CT, PET scan and Otreoscan was conducted without evidence of active disease. No tumour cells were detected on cerebrospinal fluid cytology.
Follow up with regular appointments and imagiological surveillance on our institution for 10 years without evidence of recurrence. At 10 years of initial diagnosis spinal MRI evaluation with leptomeningeal enhancement at the level of T9 and L2. The patient remained asymptomatic. No tumour cells were detected on cerebrospinal fluid citology.
Histopathologically review of the first specimen was performed. Tumour cells with a nest pattern, separated by septae and constituted by monomorphic epithelial cells without major atypia. Immunohistochemically positive for AE1/AE3, CAM5.2, synaptophysin, CD56. Weakly positive for chromogranin. Negative for TTF1, SATB2, CDX2, calcitonin, GATA3, GFAP. Estimated proliferative index Ki67 of 5%.
From this pathological review the tumour was reclassified as a paraganglioma of the filum terminal with leptomeningeal dissemination.
Surgery with L2 posterior laminectomy and complete resection of the L2 lesion was performed. Pathology review presented similar characteristics as the first specimen and was compatible with the diagnosis of paraganglioma.
Genetic studies were performed without detections of pathogenic or likely pathogenic mutations.
Imagiologic surveillance with MRI (Fig 1) and PET scans after surgery indicative of slowly progressing leptomeningeal enhancement at the T9, T12 and L3 level. No detectable extraspinal disease.