[Paraganglioma of the cauda equina region: Report of 9 cases]. / Paragangliome de la queue de cheval : à propos d'une série de 9 cas.

INTRODUCTION: The paraganglioma of the cauda equina is a rare tumor, the diagnosis is morphological and the immunohistochemistry provides a definite diagnosis. The objective of our study is to specify the clinical signs, radiological and associated pathological criteria and to compare our data with those of the literature. PATIENTS AND METHOD: This is a retrospective study of nine cases of paragangliomas of the cauda equina diagnosed in our department from 2003 to 2018. The median age of the patients was 50 years-old with a male predominance (sex ratio: 3,5/1). All patients had preoperative magnetic resonance imaging (MRI) and surgery to remove the tumor. The diagnosis was performed after HES (Hematoxylin Eosin Saffron) and immunohistochemical sections examination. RESULTS: Radiculalgia was the chief symptom of these tumors. MRI showed an oval lesion uniformly enhanced by Gadolinium in the eight patients whose records were available. Histologically, the tumors had a lobular and trabecular pattern with neuroendocrine-like cells and a rich vascularization. By immunohistochemistry, the cells expressed chromogranin, synaptophysin and CD56. DISCUSSION AND CONCLUSION: Paragangliomas of the cauda equina are rare, benign tumors. Except for cases of secreting tumors, the preoperative diagnosis is difficult. MRI is useful and may reveal radiological features suggestive of these tumors. However, it is rare for the diagnosis to be made before surgery. The diagnosis is established by histological examination and immunohistochemical techniques must be used to confirm the diagnosis. The paragangliomas of the cauda equina are well encapsulated tumors whose complete excision is curative. When the excision is incomplete, treatment with radiotherapy is recommended. Long-term clinical and radiological monitoring is recommended because of the slow evolution of the tumor and the potential for recurrence.