Ординатура / Офтальмология / Английские материалы / Moorfields Manual of Ophthalmology_Jackson_2007

Choroidal melanoma

Choroidal Melanoma

Background Choroidal melanoma (CM) is the most common primary malignant intraocular tumour. Patients are generally white, age 55–75, and have no known family history. Local tumour control can be achieved in >90% of cases. However, systemic metastasis occurs in 40% within 5 years of ocular treatment. Tumours are unilateral and rarely metastasize to the orbit or fellow eye.

Symptoms May present with vision loss, localized scotoma, metamorphopsia, and photopsia from the tumour and/or associated exudative retinal detachment. May be asymptomatic.

Signs Focal conjunctival and episcleral vascular dilation (sentinel vessels) are seen in the same quadrant as larger, more chronic ciliary body masses. Trans-scleral extension of the pigmented tumour occurs rarely. Posterior CMs are elevated, globular, tan to brown-coloured lesions (Fig. 9.17); occasionally CMs are pale (amelanotic melanoma) or minimally elevated while growing over a larger choroidal base (diffuse melanoma). Apical tumour growth through Bruchs’ membrane results in the classic hyperpigmented ‘mushroom’ or ‘collar-stud’ appearance, but rarely in tumours

<5 mm thick. Surface drusen and variable RPE hypertrophy suggest chronicity and inactivity, while the presence of subretinal fluid, exudative retinal detachment, and overlying orange lipofuscin

pigment suggests tumour activity. Vitreous and subretinal haemorrhage may occur with larger tumours.

Classification Based on anatomic origin (ciliary body, and/or choroid), growth pattern (elevated versus diffuse), posterior location (macular, juxtapapillary, or peripapillary), and, most commonly, tumour size:

■Small : thickness <2 mm, basal diameter <8 mm.

■Medium : thickness 2.5–8 mm, basal diameter 8–16 mm.

■Large : thickness >8 mm, basal diameter >16 mm.

History and examination Ask about visual symptoms, ocular surgery, cancer, and constitutional symptoms. Detailed serial ocular examination includes IOP, gonioscopy to assess for angle invasion in anterior choroid/ciliary body tumours, and dilated fundoscopy with precise tumour drawing. Transpupillary transillumination delineates the extent of ciliary body involvement.

Differential diagnosis See page 399.

Investigations Arrange colour photography for documentation and follow-up. Use ultrasonography to document size (height with longitudinal and transverse basal dimensions; note any extrascleral extension), and internal reflectivity (usually low to moderate) (Fig. 9.18). The presence of internal blood flow

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Choroidal melanoma

helps to rule out nonmalignant disease such as disciform subretinal haemorrhage. Rarely, fluorescein angiography is required. Intraoperative trans-scleral choroidal biopsy may be used to confirm the diagnosis prior to treatment if the diagnosis is unclear. If melanoma is confirmed, investigate for metastases (liver function tests, liver ultrasound, chest X-ray) and if present, refer promptly to a medical oncologist.

Treatment Treatment options are based on the results of metastatic work-up, fellow eye status, patient age, preference, and health status. In general, do not perform ocular surgery in patients with confirmed metastatic disease unless for symptomatic relief (e.g. neovascular glaucoma).

Treatment options include:

■Observation : typically for small melanomas with chronic appearance.

■Local therapy :

1.Extrascleral plaque brachytherapy: typically with ruthenium106 for tumours up to 7 mm in height, and/or

2.Local tumour resection: particularly for anterior, superonasal tumours with a small base and large height. Surgery requires specialized hypotensive anaesthesia.

3.Transpupillary thermotherapy: typically for a modest size tumour, continued or recurrent tumour growth following plaque brachytherapy in accessible, posteriorly located tumours, and for small melanomas close to the optic disc (on the nasal side) in an only or better eye.

■Enucleation : typically for large or extensively recurrent tumours, or blind, painful eyes with melanoma-induced neovascular glaucoma.

Follow–up Lifelong. Examine tumours under observation 4–6 monthly, including serial ultrasounds. After local therapy, ophthalmic examination with photo documentation and ultrasound height assessment is performed initially every 4–6 months, then yearly if there is no growth. Advise patients to return immediately if their vision changes. Postenucleation sockets are followed if extraocular extension or orbital invasion is found. Request yearly liver function tests by the general practitioner to survey for metastatic disease.

Retinoblastoma

Background The most common malignant intraocular tumour in children. Cumulative incidence at 11 years old is 4.4/100 000 births in the UK. Most (82%) cases are diagnosed before age 3, with no sex or race predisposition. The majority of cases are unilateral.

Genetics Caused by mutation in the RB1 gene. A germline mutation is often associated with bilateral disease and

autosomal dominant inheritance with almost complete penetrance (50% of offspring affected). Those with unilateral retinoblastoma are less likely to have a germline mutation or transmit the disease.

■10% of cases have a family history (FH) of an inherited germline mutation; 75% of these develop bilateral tumours.

■30% have a negative FH and develop bilateral tumours, 95% have new germline mutations.

■60% have a negative FH and develop tumours unilaterally, <10% have new germline mutations.

■Siblings with negative FH have a small risk of disease, as some (<5%) carrier parents are unaffected due to germline mosaicism.

Clinical features Classically presents with leucocoria (55%) from a large retinal tumour mass (Fig. 9.19). Secondary strabismus (25%) with decreased visual function (8%), positive FH (10%) and rarely failure to feed due to ocular pain in infants may be reported. Extraocular, fungating tumours associated with extraocular extension are rare in developed nations. Preseptal/ orbital cellulitis may occur. There may be elevated IOP (from secondary angle closure or direct tumour infiltration of the drainage angle), spontaneous hyphaema, conjunctival injection, buphthalmos, white/yellow tumour invasion into the anterior chamber or iris surface. A white/light yellow solid retinal mass is characteristic, with four growth patterns:

■Endophytic : into the vitreous cavity.

■Exophytic : into the subretinal space.

■Combined endoand exophytic.

■Diffuse : minimally thickened, extensive tumour with retinal whitening.

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Treatment

■Casualty : Refer to specialty clinic that week for diagnosis.

■Clinic : Refer to a designated treatment centre (in the UK: Barts & The Royal London Hospital, Moorfields Eye Hospital, Birmingham Children’s Hospital). Treatment is customized for each child and eye with the primary goal of local tumour control and patient survival. The secondary goal is preservation of vision. Enucleation is used for advanced local tumours or after treatment failure. Local, globe-sparing treatment options include external cryotherapy, transpupillary thermotherapy, local (sub-Tenon’s) chemotherapy, or plaque radiotherapy. Systemic chemotherapy may be used alone or with local treatments as primary or salvage therapy. External beam radiotherapy is currently used only as salvage therapy in children older than 1 year who have failed all other appropriate treatments, and who still have potential vision in their only or better eye.

Follow–up Regular review including examination under anaesthesia for recurrence/new tumours to age 7 by retinoblastoma centre then yearly by a local ophthalmologist. Arrange prompt neuroimaging in older bilateral retinoblastoma patients with new-onset CNS symptoms to look for ectopic intracranial retinoblastoma (‘trilateral retinoblastoma’). The 5-year survival rate in the UK is >95%. The cumulative incidence of second primary neoplasms in heritable cases is ≈1%/year (typically osteosarcoma/soft-tissue sarcoma).

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Optometry and general practice guidelines

Optometry and General

Practice Guidelines

General comments

Eye tumours are relatively rare, however eyelid tumours, particularly basal cell carcinoma, are not uncommon. Eyelid tumours are usually treated by oculoplastic surgeons rather than ocular oncologists and are covered in the oculoplastics chapter. The commonest referral to most ocular oncology services is a fundal naevus, to exclude (or treat) choroidal melanoma. Discriminating between naevi and melanomas can be difficult and many patients remain under regular review. The following factors suggest malignant potential: elevation, subretinal fluid, visual symptoms (blurred vision or distortion), yellow pigment (lipofuscin), and most importantly, documented growth. Low risk naevi do not routinely warrant hospital referral.

General practice

For general practitioners who are confident with an ophthalmoscope, fundal naevi may be a familiar finding, and assuming these are small, flat, discrete, and evenly pigmented, then arrange annual dilated optometry review, preferably by an optometrist with a fundus camera. If there are any worrying features refer to a general ophthalmologist.

Urgent (within 2 weeks)

Soon (within 1 month)

Routine

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