Case discussion
01Clinical context
A patient presented with transient tongue heaviness and right upper-limb numbness. Initial non-contrast CT showed a small hyperdense lesion in the right parietal lobe, prompting further MRI evaluation.
02Key imaging findings
CT revealed a small (8–9 mm) rounded hyperdense focus in the high right parietal lobe with subtle surrounding hypoattenuation, indeterminate but suggestive of a small hemorrhagic lesion such as a cavernous malformation. MRI showed a well-defined lobulated intra-axial lesion measuring approximately 15 × 7 × 8 mm with heterogeneous internal signal, prominent susceptibility blooming, and an incomplete peripheral hemosiderin rim, consistent with a cerebral cavernous malformation. Mild peripheral enhancement was present without a solid enhancing component. An associated developmental venous anomaly was identified medially. No significant edema, mass effect, or acute infarction was seen.
03Diagnostic reasoning
The initial non-contrast CT identified a small hyperdense lesion with subtle surrounding hypoattenuation in the right parietal lobe, raising suspicion for a hemorrhagic vascular lesion but remaining indeterminate. MRI was performed using multiplanar, multisequence protocols including susceptibility-weighted imaging (SWI/T2*) and diffusion-weighted imaging (DWI). Taken together, the CT appearance and the lesion's lobulated morphology, heterogeneous internal signal, susceptibility blooming and hemosiderin rim on MRI support the radiological diagnosis of a cerebral cavernous malformation (cavernoma). An associated developmental venous anomaly provides additional supporting context. No significant edema or solid enhancing component was identified. The diagnosis is based on imaging features and requires clinical correlation.
04Questions for clinical practice
What is the significance of the susceptibility blooming on MRI? It indicates blood products within the lesion, characteristic of cavernous malformations. How does the associated developmental venous anomaly affect management? It is a benign vascular variant often seen with cavernomas and usually does not require treatment but should be noted to avoid surgical complications. When should follow-up imaging be considered? Follow-up depends on clinical symptoms and neurological consultation; stable lesions without new symptoms may not require routine imaging. Does the mild peripheral enhancement suggest malignancy? No, mild peripheral enhancement without a solid enhancing component is typical for cavernous malformations and does not indicate aggressive disease.
05Teaching point
Small hyperdense lesions on non-contrast CT in patients with focal neurological symptoms can be indeterminate. MRI with susceptibility-sensitive sequences is essential for characterizing cerebral cavernous malformations, differentiating them from other hemorrhagic lesions, and identifying associated vascular anomalies. This guides appropriate neurological referral and management.
Shown for education. De-identified — no identifiable patient data. A radiology report is a specialist opinion and must be read with the full clinical context by the treating physician.