Magnetic resonance characteristics of adult-onset Lhermitte-Duclos disease: An indicator for active cancer surveillance?

Lhermitte-Duclos disease (LDD) is a rare, non-cancerous entity characterized by enlarged, abnormally developed cerebellar folia containing dysplastic cells. Symptomatic LDD is commonly observed in adults (adult-onset LDD, aLDD) as an isolated condition or associated with Cowden's disease (CD). The present study aimed to investigate the magnetic resonance imaging (MRI) characteristics and the underlying pathological findings in 7 cases of aLDD, with emphasis on the association with CD and the need for active cancer surveillance once the diagnosis of LDD is confirmed. The MRI findings along with the clinical and histopathological data collected from 7 patients with aLDD were retrospectively reviewed. The diagnosis of CD was based on a range of clinical characteristics, according to the International Cowden Consortium Criteria. A thorough review of the published data was conducted and our results indicated that all 7 cases shared similar MRI characteristics, whether the aLDD was sporadic (2 cases) or associated with CD (5 cases), including a highly typical non-enhancing striated MRI appearance of thickened folia, consisting of alternating bands on T1- and T2-weighted images. On gross examination, the involved cerebellar folia were distorted and enlarged, whereas the histopathological examination revealed that the molecular layer was widened and occupied by abnormal ganglion cells. Moreover, a reduction in the number or absence of the Purkinje cells and hypertrophy of the granular cell layer were observed. Our findings were consistent with the diagnosis of LDD. Variable levels of vacuolization of the white matter and the molecular layer were observed in all the cases. Notably, CD34 immunohistochemical analysis revealed the presence of angiogenesis within the lesions. aLDD associated with CD exhibited no pathological or immunohistochemical characteristics that were distinct from those of isolated aLDD. Of the 7 cases of aLDD, 5 presented with symptoms suggestive of CD, which is a syndrome associated with a high risk of multiple benign and malignant neoplasms. In conclusion, aLDD exhibits characteristic MRI and histopathological findings and displays a strong association with CD. Therefore, we recommend that the MRI diagnosis of aLDD triggers active cancer surveillance and preventive care.