Teaching NeuroImages: MRI appearances of Lhermitte-Duclos disease

High-Definition Fiber Tractography in the Evaluation and Surgical Planning of Lhermitte-Duclos Disease: A Case Report

BACKGROUND

Preoperative delineation of normal tissue displacement patterns in Lhermitte-Duclos disease has not been feasible with conventional imaging means. Surgical resection of this type of lesion remains challenging, because the boundaries of the lesion are indistinguishable during surgery.

CASE DESCRIPTION

The clinical presentation, preoperative and postoperative magnetic resonance imaging (MRI) findings, high-definition fiber tractography (HDFT) and histopathological studies, are presented in a 46-year-old male subject with symptomatic Lhermitte-Duclos disease. HDFT was performed using a quantitative anisotropy-based generalized deterministic tracking algorithm to define fiber tracts. Displacement of the cerebellar and brainstem tracts on the affected side was performed using the unaffected contralateral side as a comparison. The displacement of the normal tissues was not apparent on preoperative MRI but was immediately evident on the preoperative HDFT. Of note, there was a relative paucity of fiber tracts within the lesion. By tailoring our operative boundaries based on the HDFT findings, we were able to spare the displaced fiber tracts when debulking the tumor. Restoration of normal fiber tract anatomy on postoperative HDFT imaging was correlated with clinical resolution of preoperative symptoms.

CONCLUSIONS

This case report suggests that HDFT may be a powerful surgical planning tool in cases of Lhermitte-Duclos disease, in which the pattern of normal tissue displacement is not evident with conventional imaging, allowing maximal lesion resection without damage to the unaffected tracts. Therefore, this report contributes to solving the greatest challenge when operating on this type of lesion, which has not been resolved in any previous report in our review of the English literature.