Recurrent multiloculated cystic variant of Lhermitte-Duclos disease managed with cyst fenestration and Ommaya reservoir placement: illustrative case

Abstract

BACKGROUND

Lhermitte-Duclos disease (LDD), or dysplastic gangliocytoma of the cerebellum, is a rare benign lesion typically characterized by slow growth and absence of cystic changes. Cyst formation in LDD is distinctly uncommon, and detailed clinical courses of such cases are rarely documented.

OBSERVATIONS

The authors describe a case of a young male with multiloculated cystic LDD in the right cerebellar hemisphere. The lesion recurred with progressive cyst enlargement, ultimately causing brainstem compression. Despite multiple resections and fenestrations, histopathological analysis consistently revealed characteristic features of LDD, including thickened cerebellar folia with reduced Purkinje and granular cells, dysplastic neurons, and a very low Ki-67 index (≤ 1%). Final management, including cyst fenestration and placement of an Ommaya reservoir, successfully restored CSF communication, preventing further enlargement and stabilizing neurological symptoms.

LESSONS

Although LDD generally follows a benign course, multiloculated cystic variants can present with progressive recurrence and neurological deterioration. This case emphasizes the importance of recognizing cystic changes in LDD and demonstrates that adequate fenestration with communication to cisternal spaces, supplemented by Ommaya reservoir placement when necessary, can provide durable disease control.

https://thejns.org/doi/10.3171/CASE25907

Lhermitte-Duclos disease (LDD) is a rare hamartomatous or benign tumor-like lesion of the cerebellum, classified as a World Health Organization grade 1 tumor of the CNS.^1,2 Histopathologically, it is characterized by thickened cerebellar folia, reduced granular cell layer, and loss of Purkinje cells, reflecting dysplastic changes in the cerebellar cortex.^3,4 Although the exact pathogenesis remains unclear, mutations in the PTEN gene have been reported, and an association with Cowden syndrome has been suggested.^3,5

Clinically, LDD typically follows an indolent course, and the lesion is often extensive at the time of diagnosis. On neuroimaging, a “tiger stripe” appearance on T2-weighted MRI is considered a hallmark finding.^3,6–8 LDD generally presents as a solitary lesion, while cystic change is distinctly uncommon.⁹ Furthermore, recurrence or regrowth is exceedingly rare.

Here, we describe an unusual case of LDD in a young male, characterized by recurrent multiloculated cystic lesions of the right cerebellar hemisphere that required multiple resections and cyst fenestrations. Histopathological examinations consistently confirmed features of LDD. This case underscores the clinical, radiological, and pathological diversity of LDD and provides insight into surgical strategies for managing cystic variants.

Illustrative Case

Clinical Presentation and Initial Surgery

A man in his early 20s, with no remarkable medical or family history, was transported to a hospital after a near-drowning accident. CT of the head incidentally revealed a multiloculated cystic lesion with calcification extending from the right cerebellar hemisphere to the pons. Although the fourth ventricle was compressed, hydrocephalus was absent. MRI demonstrated a multiloculated cystic mass involving the right cerebellar hemisphere, vermis, and pons (Fig. 1). T2-weighted MRI showed a striated pattern in the cerebellar hemisphere with mild perilesional edema, and gadolinium-enhanced T1-weighted MRI showed partial enhancement.

FIG. 1.

Preoperative MR images and CT scans obtained at the referring hospital. A and B: Axial T1-weighted MR images showing a hypointense to isointense lesion in the right cerebellar hemisphere with linear striations and multiple cystic components. C and D: Axial T2-weighted MR images demonstrating multiloculated cystic lesions with parallel hyperintense streaks in the cerebellar cortex. E and F: Axial contrast-enhanced T1-weighted MR images revealing scattered enhancement within the lesion. G and H: Axial CT scans showing calcification around the cystic wall.

The patient underwent craniotomy and resection of the lesion at the hospital. Histological examination revealed thinning of the granular cell layer and loss of Purkinje cells. The thickened molecular layer contained occasional large dysplastic ganglion cells with prominent nucleoli, accompanied by microvascular proliferation and small nodular calcifications. Bodian staining demonstrated disorganized axon terminals surrounding the large dysplastic ganglion cells. Based on these findings, a diagnosis of LDD was made.

Recurrence and Second Surgery

A residual lesion was observed radiologically; however, conservative management was chosen. Approximately 3 years later, the patient developed gait unsteadiness, and MRI showed regrowth of the cystic lesion in the right pontine region, prompting referral to our institution.

On admission, the patient presented with right abducens nerve palsy with diplopia on right gaze, mild weakness of the left upper limb, and right-sided dysmetria on finger-to-nose testing, although he remained ambulatory.

A second craniotomy with resection of the lesion and cyst fenestration was performed under intraoperative monitoring of motor evoked potentials, auditory brainstem responses, and facial nerve function. Postoperatively, diplopia partially improved, and CT confirmed a reduction in cyst volume. However, a surgical site infection was suspected, requiring lumbar drainage and antibiotic therapy with vancomycin and cefepime. Purulent discharge and bacterial meningitis necessitated bone flap removal and surgical debridement. Following treatment, inflammatory markers improved, and the patient was discharged. Multigene panel testing was proposed but declined by the patient.

Third Surgery and Shunt Placement

Five months later, dysarthria, numbness of the left extremities, and worsening gait disturbance recurred. MRI confirmed regrowth of the cystic lesion with compression of the fourth ventricle. A third surgery involving lesion resection and cyst fenestration was performed, followed by placement of a ventriculoperitoneal shunt for hydrocephalus. The patient’s gait disturbance improved postoperatively, and he was transferred for rehabilitation.

Cyst Fenestration and Ommaya Reservoir Placement

Approximately 6 months later, further regrowth of the cystic lesion with brainstem compression was observed. To achieve durable cyst decompression, a navigated 8-Fr Nelaton catheter (Terumo Corporation) was initially inserted to fenestrate the multiloculated cysts. The catheter tract was progressively dilated by exchanging the 8-Fr catheter for a 10-Fr catheter, thereby enlarging the fenestration and establishing communication between the cystic cavities and cerebellopontine angle cistern, allowing continuous CSF egress. An Ommaya reservoir (Integra Life Sciences) was subsequently implanted along the same tract to maintain access to the cystic system and to provide a safeguard for potential future decompression. Postoperative CT confirmed that the reservoir tip was positioned within the cistern. At the latest follow-up, 1 year after Ommaya reservoir placement, the patient was able to ambulate independently. Serial MRI demonstrated sustained reduction and stability of the cystic components without further enlargement, and aspiration through the Ommaya reservoir has not been required (Fig. 2).

FIG. 2.

Clinical course, surgical interventions, and sequential T2-weighted MRI (T2WI) findings. Representative pre- and postoperative images are shown for each surgical stage, with an emphasis on the cystic components to illustrate interval changes in cyst size rather than the extent of parenchymal resection. After Ommaya reservoir placement, no further cyst enlargement was observed. The distal catheter tip was positioned within the cerebellopontine angle cistern to establish communication between the cystic cavities and the subarachnoid space (arrowheads). A: Intraoperative view during the second resection showing slightly swollen and pale cerebellar folia with poor demarcation from the surrounding normal tissue and surface cystic changes. B and C: Intraoperative views during Ommaya reservoir placement. A Nelaton catheter (B) was inserted under navigation guidance to establish the tract. Stepwise fenestration of multiple cysts (C), including deeper cystic components, was performed along the catheter tract, resulting in continuous CSF egress and communication with the cistern. An Ommaya reservoir was implanted at the proximal end of the same tract to provide access in case of future cyst reexpansion.

Histopathological Findings

Histopathological examination of all surgical specimens consistently showed thickened cerebellar folia with reduced Purkinje and granular cells, along with scattered medium to large dysplastic ganglion cells. No atypical cells suggesting malignancy or neoplastic glial components were observed. Immunohistochemistry demonstrated positive staining of large dysplastic ganglion cells for synaptophysin and neurofilament, with a Ki-67 index ≤ 1%. These findings were fully consistent with the diagnosis of LDD (Fig. 3).

FIG. 3.

Histopathological findings from the second (A–D) and third (E–H) resections. A: Thickened cerebellar folia with loss of granular cells and calcification (hematoxylin and eosin [H&E]). B: Small cluster of dysplastic ganglion cells (H&E). C: Dysplastic ganglion cells positive for synaptophysin. D: Very low Ki-67 proliferative index. E:Thickened folia with disappearance of granular cells (H&E). F: Numerous dysplastic ganglion cells with prominent vacuolation (H&E). G:Dysplastic ganglion cells positive for synaptophysin. H: Very low Ki-67 index ≤ 1%. Original magnification ×100 (A and E), ×400 (B–D and F–H).

Informed Consent

The necessary informed consent was obtained in this study.

Discussion

LDD, also referred to as dysplastic gangliocytoma of the cerebellum, is a rare entity characterized by disorganized architecture of the cerebellar cortex. It most frequently occurs in young to middle-aged adults. While patients commonly present with symptoms of increased intracranial pressure or cerebellar dysfunction, the slow progression of the disease may render it asymptomatic in some cases. On neuroimaging, the characteristic tiger-striped laminated pattern of high signal intensity on T2-weighted MRI has been described,^6,8,10 although it is not observed in all cases. Contrast enhancement and calcification may occasionally occur,^3,11–13 necessitating the integration of radiological and histopathological findings for diagnosis.

The present case is notable for its association with multiloculated cysts and calcification in the right cerebellar hemisphere, along with repeated recurrences requiring multiple surgical interventions. Since its first description in 1920, approximately 300 cases of LDD have been reported.^3,13 However, cystic change is not a typical feature, and only a few cases with cyst formation have been described.^14–16 Reports detailing multiloculated cystic formation with progressive recurrence, as seen here, are exceptionally rare.

In the differential diagnosis of cystic cerebellar lesions, neoplasms such as ganglioglioma and pilocytic astrocytoma should be considered.^17–19 In the present case, however, histopathological analysis of all resections consistently demonstrated the characteristic features of LDD, including thickened cerebellar folia, reduced Purkinje and granular cells, and scattered dysplastic ganglion cells. Immunohistochemistry further confirmed the diagnosis, showing synaptophysin and neurofilament positivity and a low Ki-67 index (≤ 1%). No atypical or malignant features were observed. Although a case of an anaplastic ganglioglioma with cystic areas arising from an LDD-like lesion has been reported,²⁰ our case was distinct because cystic changes were present on the initial MRI, and no neoplastic elements were identified. An association with dysembryoplastic neuroepithelial tumor has also been described in reported cases,¹⁸ but those cases demonstrated oligodendrocyte-like cells in addition to hamartomatous changes, which were absent in our patient. Although the possibility of an undetected small neoplastic component cannot be entirely excluded, the consistent absence of such elements across multiple resections supports the interpretation that cystic changes can occur as part of the natural course of LDD.

The typical clinical course of LDD is slow and benign. However, as illustrated in this case, multiloculated cystic enlargement can result in progressive neurological symptoms such as hydrocephalus and brainstem compression. In our patient, cyst growth was clearly associated with worsening neurological deficits, necessitating repeated interventions. Given the hamartomatous nature of LDD, gross-total resection is not always required.^14,21 Our management strategy focused on adequate fenestration of the cysts rather than radical removal of the lesion. Ultimately, fenestration combined with Ommaya reservoir placement effectively controlled cyst recurrence and stabilized the neurological symptoms. This underscores the importance of ensuring adequate communication between the cyst and the ventricular system or cisterns in cases of cystic LDD.

Reports on the surgical management of cystic LDD remain scarce. In the present case, the cyst contents were clear serous fluid, distinct from those of cysts associated with malignant tumors; therefore, treatment strategies could be adapted from the management of arachnoid cysts. For arachnoid cysts, decompression and establishment of communication with the subarachnoid space or ventricular system are essential.^22–25 In the present case, fenestration successfully restored CSF circulation and prevented recurrence. Although cystoperitoneal shunting has been described in arachnoid cysts, it is associated with shunt dependency, reoperation, and long-term complications.²² Considering the potential risk of acute brainstem compression from recurrent expansion, Ommaya reservoir placement was chosen. Following the establishment of communication with the cistern, the cyst remained controlled without aspiration, supporting this approach. Given that LDD arises in the posterior fossa, long-term risk management must be carefully incorporated into treatment planning when cystic changes are present.

Although the precise mechanism of cyst formation in LDD remains unclear, several factors may have contributed to this rare phenotype. Marked thickening of the cerebellar folia and architectural distortion may alter local CSF dynamics, leading to focal CSF trapping and subsequent cyst formation, particularly within the confined space of the posterior fossa. In addition, microvascular changes reported in LDD may facilitate gradual fluid accumulation within the lesion. From a molecular perspective, LDD has been linked to dysregulation of the PI3K/AKT/mTOR pathway, most commonly through PTEN alterations, which have been associated with microvascular proliferation and may increase vascular permeability.²⁶ However, the relevance of these molecular and vascular associations to cyst formation remains unclear. In the present case, the presence of multiloculated cysts at the initial presentation suggests that cystic changes can represent an intrinsic, albeit uncommon, manifestation of LDD rather than a purely postoperative phenomenon. Future studies focusing on cyst fluid characteristics and regional CSF circulation may help clarify the underlying mechanisms of cyst formation in LDD.

Observations

We report a rare case of LDD in the right cerebellar hemisphere that presented with multiloculated cystic changes and repeated regrowth. Although LDD is generally indolent and benign, progressive cystic enlargement can precipitate neurological deterioration through brainstem compression and hydrocephalus, necessitating timely surgical intervention. In our case, repeated resections and cyst fenestrations were required, but long-term stabilization was ultimately achieved by establishing communication between the cysts and the cistern and implanting an Ommaya reservoir.

Lessons

This case highlights the importance of tailoring surgical strategies to cystic variants of LDD, with an emphasis on restoring CSF pathways rather than pursuing radical resection of the lesion. The limitations of this report include its being a single case and the absence of genetic analysis, as the patient declined multigene panel testing. Nevertheless, our observations add to the limited literature on cystic LDD and suggest that Ommaya reservoir placement may represent a safe and effective strategy for preventing recurrent cyst enlargement in selected patients. Further accumulation of similar cases will be necessary to clarify the pathophysiology and establish optimal treatment approaches.

Acknowledgments

We thank Editage for English-language editing. We used ChatGPT (OpenAI) exclusively for grammar correction and language polishing purposes. We wrote, verified, and approved all scientific content and take full responsibility for the final manuscript.

Disclosures

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

Author Contributions

Conception and design: Hiu, Uchida, Matsuo, Yoshida. Acquisition of data: Hiu, Uchida, Yamaguchi, Ujifuku. Analysis and interpretation of data: Hiu, Uchida, Masui, Matsuo. Drafting the article: Hiu, Uchida, Nakamura. Critically revising the article: Hiu, Uchida, Yamaguchi, Matsunaga, Morofuji. Reviewed submitted version of manuscript: Hiu, Yamaguchi, Takeuchi, Shirahama, Ogawa, Matsuo, Matsunaga, Baba, Ujifuku. Approved the final version of the manuscript on behalf of all authors: Hiu. Administrative/technical/material support: Hiu, Yamaguchi, Matsuo, Baba. Study supervision: Hiu, Yoshida, Morofuji, Matsuo.

Correspondence

Takeshi Hiu: Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. takeshihiu@nagasaki-u.ac.jp.