Orbital tumours

Question 1

What is the most common site for uveal metastases?

Answer 1

The choroid (90%), followed by the iris and ciliary body

Question 2

Where is the most frequent primary sites of metastatic eye tumours?

Answer 2

@ The breast

    @ The bronchus

    @ A choroidal secondary may be the initial presentation of a bronchial carcinoma, wheras a past history of breast cancer is the rule in patients with breast secondaries.

    @ The gastrointestinal tract

    @ The kidney

    @ Skin melanoma

    @ The prostrate (an extremely rare primary site)

Question 3

What is important to know about patient survival(regarding metastatic tumours)?

Answer 3

It is generally poor with a median of 8 - 12 months

Question 4

What are the signs of metastatic intra-orbital tumours?

Answer 4

@ A fast-growing

    @ creamy-white

    @ placoid lesion

    @ with indistinct margins

    @ most frequently located at the posterior pole

     @ that may occasionally exhibit black pigment clumps on its surface

    @ in some cases the deposits are globular in shape

    @ may mimic an amelanotic melanoma although they NEVER exhibit a mushroom configuration

    @ the deposits are multifocal in 30% of patients

   @ bilateral in 10% - 30% of cases

    @ Secondary exudative retinal detachment is frequent

Question 5

Ultrasound findings of metastatic eye tumours?

Answer 5

@ A placoid tumour shows diffuse choroidal thickening

    @ A dome-shaped lesion shows moderately high internal acoustic reflectivity throughout the tumour (suggestive but not pathognomonic)

Question 6

How can a FA distinguish between metastatic lesion and a MM?

Answer 6

@ Metastatic lesion: early hypoflorescence and diffuse staining

    @ Choroidal melanoma: dual circulation

Question 7

What important special investigation should always be done in metastatic eye tumours?

Answer 7

Full body CT

Question 8

What is the management of metastatic eye disease?

Answer 8

@ Observation, if:

          - the patient is asymptomatic or
         - receiving systemic chemotherapy

    @ Radiotherapy, either external beam or brachytherapy

    @ TFT is useful for small tumours with minimal subretinal fluid

    @ Systemic therapy for the primary tumour may also be beneficial for choroidal metastases

                                                                      KANSKI, 7th Edition, pages 506, 507, 509, 510

Question 9

What is the most frequent intraocular tumor?

Answer 9

@ Most ophthalmologists would comsider uveal melanoma to be the most common intraocular malignancy

    @  Numerous studies in the last 30 years have shown that cancer metastasis to the uvea is by far the most frequent  intraocular tumor

CLINICAL. OPHTHALMIC. ONCOLOGY, Arun Singh, Bertil Damato, 2007, page 322

Question 10

Findings suggestive of a diagnosis of uveal melanoma rather than metastasis are:

Answer 10

@ pigmentation

    @  double circulation: retinal vessels overlying clearly identifiable tumor vessels

    @  unifocal location

    @  mushroom shape

    @. slow tumor growth CLINICAL  OPHTHALMIC  ONCOLOGY, Arun Singh, Bertil Damato, 2007, page 325

Question 11

What is the only surgical approach for metastatic carcinoma?

Answer 11

@ Enucleation in advanced cases with loss of function and painful secondary glaucoma

Question 12

What is Tamoxifen?

Answer 12

@ Tamoxifen is a specific anti-oestrogen used in the treatment of selected patients with breast carcinoma

Question 13

What are the characteristics of Tamoxifen retinopathy?

Answer 13

@ bilateral

    @  superficial

    @  fine

    @  yellow

    @  crystalline deposits (in the inner layers of the retina)

    @  punctate, grey lesions in the outer retina and RPE

Question 14

What is the cause of the visual impairment caused by Tamoxifen?

Answer 14

@ Maculopathy associated with foveolar cyst formation

Question 15

Name a rare side-effect of Tamoxifen therapy

Answer 15

Optic neuritis (reversible on cessation of therapy

Question 16

Name the causes of macular crystals

Answer 16

@ Canthaxanthin: a carotenoid used to enhance sun tanning (dough nut shape)

    @  Methoxyflurane (Penthrane): o

          - an inhalant general anaesthetic
          - is metabolized to oxalic acid
          - which combines with calcium
          - to form an insoluble salt
          - which is deposited in tissues including the RPE as black calcium oxylate crystals
         - prolonged use may lead to renal failure

@ Nitrofurantoin: an antibiotic used in the treatment of urinary tract infections (circinate pattern)

    @   Bietti corneoretinal  crystalline dystrophy

    @  Cystinosis

    @. Sjogren-Larsson syndrome

    @  Gyrate atrophy

    @  Acquired parafoveal telangiectasis

    @. talc-cornstarch emboli

    @  West African crystalline maculopathy

KANSKI 7th Edition, page 866