A 20 yr female come with a mass in the cavernous sinus & 6th cranial nerve palsy. In T2W MRI Hyperintense shadow is present which shows homogenous contrast enhancement. Diagnosis is:
B i.e. Meningioma Tumors or lesions (like infection, thrombosis, aneurysm, fistula) of cavernous sinus can cause neuropathy/involvment of 3rd, 4th 6th and 5th (V1 >>112.) cranial nerves because of their anatomical proximity to the lateral wall of cavernous sinus. So for pin pointing the diagnosis we have to focus on other features like sex, age, incidence and MR findings. Now lets focus on differential diagnosis of cavernous sinus masses which indicates that Schwannoma & meningioma are common; cavernous sinus hemangioma is very rare and astrocytoma is almost not a cause cavernous sinus masses. Unilateral Mass Common Uncommon - SchwannomaQ - Chordoma - MeningiomaQ - Lymphoma - Metastasis Very Rare - Aneurysm (cavernous- - Lipoma internal carotid aery) - Carotid cavernous - Epidermoid fistula - Cavernous hemangiome - Osteo cailagenous tumors - Plexiform neurofibroma (NF1) Bilateral Mass Common Uncommon - Invasive pituitary adenoma - Meningioma - Metastases - Lymphoma - Cavernous sinus thrombosis Lets focus on astrocytoma to see wheter it can be completely ruled out or not - Astrocytomas either do not/mildly enhance (low grade astrocytoma) or strongly enhance (anaplastic/malignant astrocytoma, glioblastoma multiformae, PA, PXA, SEGA) but when they enhance they characteristically enhance inhomogenously (heterogenously) mostlyQ (except in PXA >PA). Now we are left with cavernous hemangioma, meningioma and schwannoma Cavernous sinus hemangioma is a rare benign tumor seen in young or middle aged (4th & 5th decade) predominantly females (F:M = 9:1 to 3:1). It presents as homogenous hypointense on T1 and highly hyperintense on T2 weighted images. Contrast enhancement is homogenousQ, which distinguish them from other lesions. So it seems a probable answer but lets rule out other options. Trigeminal Schwannoma (neuroma) is a common cause of cavernous sinus mass. It presents predominantly in females (F:M=2:1) of 35 to 60 years ageQ. But it is characterized by high chances (3040%) of heterogeniety of both density and contrast enhancementQ (b/o tumor necrosis & cyst formation in larger > 1 mm tumors). So schwannoma can be easilyruled out. Meningiomas are common cause of cavernous sinus mass. It presents predominantly in females (F:M=4:1 to 2:1) of 35 to 70 years and even in younger patients in Wzv NF2Q. Meningiomas are characteristically homogenous hyperdense mass (with broad dural base) on CT and characteristically show homogenous (uniform) intense contrast enhancementQ. So this is the answer because it is far more common than CSH. Dont get confused that ----book mention, meningioma may be heterogenous without understanding the logic behind it. Brodly speaking any tumor may give any appearance but we are concerned about its typical / characteristic/ most common pattern of appearance. This and most of PGME question about CNS tumors are very broad concept based. Now let me rephrase this question to make it more clear : What would be your first diagnosis of cavernous sinus mass which appears hyper intense on T2 WI and shows homogenous contrast enhancement in a 20 yr old female.
Schwannoma
Meningioma
Astrocytoma
Cavernous sinus hemangioma