Metastatic Intracranial Lymphoma

KEY FACTS

TERMINOLOGY

• Secondary CNS involvement in patients with systemic

lymphoma (SCNSL)

IMAGING

• Secondary CNS lymphoma: Skull, dura, leptomeninges > >

parenchymal mass

• Best diagnostic clue: Diffusely enhancing dural mass ± bone

involvement

○ May see leptomeningeal enhancement or nonsupression

of cerebrospinal fluid on FLAIR; CT hyperdensity

• Lower relative cerebral blood volume than other tumors

TOP DIFFERENTIAL DIAGNOSES

• Meningioma

• Meningeal metastases

• Primary CNS lymphoma

• "Tumefactive" demyelinating disease (MS, ADEM)

CLINICAL ISSUES

• Prognostic markers suggestive of CNS relapse

○ Elevated serum lactate dehydrogenase levels

○ Presence of B symptoms

○ Extranodal involvement at > 1 site

○ Advanced stage

• Aggressive histologic features increase risk for SCNSL

• Involvement of liver, bladder, testis, or adrenals also

increases risk of CNS spread

• CNS involvement of lymphoma almost always fatal

• Prophylactic CNS chemotherapy recommended for

patients considered at high risk of CNS recurrence

DIAGNOSTIC CHECKLIST

• Occult lymphoma found in 8% of patients presenting with

CNS lymphoma

• SCNSL commonly mimics meningioma or other metastatic

disease

(Left) Axial CECT shows

extensive dural enhancement

﬇ related to metastatic

intracranial lymphoma.

Secondary lymphoma has a

propensity for the meninges.

About 1/3 of systemic

lymphoma patients develop

CNS disease. (Right) Axial T1

C+ MR shows an enhancing

central skull base mass ﬈

with associated dural ﬇ and

leptomeningeal enhancement

ſt within the internal

auditory canals. The clivus is

often involved by metastatic

disease, particularly breast

cancer and lymphoma.

(Left) Axial T1 C+ MR in a 54-

year-old man with systemic

lymphoma shows multiple

enhancing masses. Some

lesions involve the dura ﬇,

whereas others are

parenchymal ſt. Metastatic

intracranial lymphoma often

involves the dura and may

mimic a meningioma. (Right)

Axial T1WI C+ FS MR shows

enhancement along the

maxillary division (V2) of CN5

ſt, extending from the

cavernous sinus into the

pterygopalatine fossa ﬇, in

this patient with systemic

lymphoma and new facial

paresthesias.

Brain: Pathology-Based Diagnoses: Neoplasms,

Cysts, and Disorders

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