Optic nerve leukemia

Enlarged ON with avid enhancement in patient with rapidly deteriorating vision.

See discussion later.

Less preferred but may be first imaging study.

• Radiation to orbit is undesirable.

• Less effective in demonstrating extent of disease.

Enlarged ON with irregular margins and avid enhancement in patient with rapid vision deterioration.

T1 gadolinium (Gd) with mild enhancement better demonstrated with fat saturation.

T2 may demonstrate reduced or absent cerebrospinal fluid (CSF) in involved ON sheath(s).

T1 Gd demonstrates abnormal enhancement of ON sheath(s) and ON (which may or may not appear together). (See later.)

Clearly the case shown in Figure 38-1 , B, has involvement of ON and ON sheath.

Other cases have clear involvement of ON sheath, with relative sparing of ON producing a “tram track” appearance.

Magnetic resonance imaging (MRI) findings in an individual patient may depend on the disease stage in which the images were acquired.

• Stage I (early): Mild ON enlargement with reduced or absent CSF in ON sheaths.

  • This may be overlooked.

• Stage II (later): T1 Gd enhancement of ON sheath with tram track appearance sparing ON proper.

  • This may resemble ONM.

• Stage III (late): T1 Gd enhancement of ON and ON sheath with no apparent distinction between them.

  • This may resemble optic nerve glioma (ONG).

• Stage IV (very late): T1 Gd enhancement of ON and ON sheath with irregular borders and tumor infiltrating into adjacent perineural fat.

  • This may resemble metastasis.

  • See Figure 38-1 .

Magnetic resonance imaging (MRI) with contrast is:

• Preferred imaging procedure.

• MRI with Gd and fat saturation can detect and demarcate ONL with accuracy not attainable by other current imaging techniques.

• Better at defining disease extension into orbital apex, optic canal, and intracranial structures.

• Better at demonstrating other extraorbital findings.

• Allows sequential follow-up of patient without increasing cumulative radiation dose.

• Fat saturation imaging is helpful in evaluation of subtle lesions.

Pressure-like eye pain.

Progressive vision loss.

• May progress to no light perception within days.

Widespread retinal hemorrhage is prevalent.

Symptoms related to increased intracranial pressure include:

• CNS symptoms: nausea and vomiting, lethargy, seizures.

• Ocular symptoms:

  • Blurred vision and visual acuity loss.

  • Diplopia with cranial nerves (CNs) III, IV, and VI involvement.

  • Papilledema may be only visual symptom if only CN II involved.

  • Papilledema is the most frequent sign of ONL (although ONL may have no papilledema).

All types of leukemia may affect orbit, but involvement by ALL is most common.

Over the last 40 years, ALL has morphed from a fundamentally fatal to a highly curable disease.

ALL is a difficult disease demanding multifaceted, multispecialty management.

Approximately 90% of patients with ALL have some orbital involvement. ^,

ON involved in 13% to 18% of patients with leukemia.

ONL predicts poor prognosis, particularly if patient is still receiving treatment. ^,

Leukemic patients with orbital involvement have significantly lower survival rates.

Ocular involvement usually occurs during development of illness, but may be a harrowing harbinger of postremission relapse. ^,

Every patient with ALL should have periodic complete ophthalmologic examinations, starting at diagnosis, to detect ocular involvement. ^{, ,}