Patient History

44Y, Male. 

• Chief Complain: Brainstem lesion identified more than two years ago; left facial numbness for the past two weeks. 

• History of Present Illness: The patient was initially diagnosed with a brainstem spaceoccupying lesion two years ago during a post-trauma examination and has been under regular outpatient monitoring since. Left facial numbness developed suddenly two weeks ago. 

• Past Medical History: No significant prior medical conditions.

• Physical Exam: Reduced sensation and diminished corneal reflex on the left side of the face. 

• MRI: Cerebral cavernous malformation (CCM) with hemorrhage in the left pons and middle cerebellar peduncle. 

• Diagnosis: Hemorrhagic CCM in the left pons–middle cerebellar peduncle region.

Imaging & Clinical Course

FIGURE 1：Aug 2022 MRI: A space-occupying lesion located between the trigeminal and facial–vestibulocochlear nervein the left pons–cerebellar peduncle region.

FIGURE 2：Aug 2022 DSA: No abnormalities detected.

FIGURE 3：Aug 2024 MRI: Significant enlargement of the lesion compared to previous imaging, with evidence of recent bleeding.

FIGURE 4：Aug 2024 MRI (SWI): Confirmed CCM with associated stroke.

Treatment Plan

• Location and Qualification: Hemorrhagic CCM between the trigeminal and facial nerves in the left pons–cerebellar peduncle area.

• Surgical Approach: Left suboccipital retrosigmoid approach (posterior to the sigmoid sinus).

FIGURE 6：Intraoperative Anatomical Schematic

 Postoperative Imaging

• Gross Description:

• (Brainstem lesion) One irregular gray-yellow to dark brown tissue fragment (0.9×0.5×0.3 cm), firm consistency. Entire specimen submitted.

  
  

• Microscopic Description:

• Thin-walled vascular channels of varying sizes lined by flat endothelial cells and filled with blood.

  
  

• Pathological Diagnosis:

• (Brainstem lesion) Malformed vascular tissue with hemorrhage. Mild gliosis and hemosiderin deposition present.

 FIGURE 8：Postoperative Pathology

• Characteristic of Brainstem CCM:
  

• Brainstem CCM often exhibits expansile growth and may compress adjacent structures.

• Hemorrhagic types are surrounded by a hemosiderin ring.

• Surgery is still debated but may be indicated in symptomatic cases.

• Literature Recommendations:

• Surgical intervention can be considered for symptomatic hemorrhagic brainstem CCMs.

• Timing of Surgery:

• Optimal window is 2–3 weeks post-hemorrhage.

• Approach Selection: Brown’s two-point method and safe entry zone approaches are recommended.

• CSF Leak Prevention: 

• Prevention outweighs treatment.

• When the dura is deficient or the suture line is under tension, use a dural substitute graft with suturing, then apply a dural sealant to achieve a watertight closure.

• Perform layered, meticulous closure of the muscle and galea aponeurotica.

• These measures can effectively reduce CSF leakage and lower the incidence of central nervous system and incisional infections.