Benign Melanocytic Lesions Of The Ciliary Body And Choroid

Front 1

What is a nevus?

Back 1

a congenital hamartoma
Atypical, benign-appearing melanocytes

Front 2

What are the BENIGN melanocytic lesions that occur in the CB and Choroid called?

Back 2

Nevi

Front 3

In what percentage of people are nevi found in the CB and choroid?

Back 3

30%

Front 4

What percentage of people have multiple nevi in the same eye?

Back 4

7%

Front 5

In what percentage of people are one or more nevi found BILATERALLY?

Back 5

3 - 4%

Front 6

What percentage of people with choroidal nevi, have iris freckles too?

Back 6

55%

Front 7

What percentage of people have iris freckles without choroidal nevi?

Back 7

20%

Front 8

Is there a sex predilection in patients with CB or choroidal nevi?

Back 8

No, M=F

Front 9

Are choroidal and CB nevi common in children?

Back 9

NO! it is extremely low!

Front 10

What happens to the incidence as a person ages?

Back 10

The incidence increases progressively during the 2nd, 3rd, and 4th decades, and then levels off at approx 35% of people

Front 11

Where do nevi occur in the CB and Choroid?

Back 11

91% in the posterior 1/2
59% in the posterior 1/3

Almost equal incidence in the anterior 1/3 of the choroid and CB.
5% in anterior choroid
6% in the CB

Front 12

What is the range in size of a nevus of the choroid and CB?

Back 12

Nevi: 0.5 - 11mm (0.33 - 7DD)

95% are 3mm (2DD) or less

Front 13

what thickness of the choroid does the nevus usually involve?

Back 13

The FULL thickness of the choroid, excluding the choriocapillaris.

Front 14

Describe the shape of a choroidal nevus

Back 14

Flat, discoid lesions

67% > the thickness of the surrounding choroid

Front 15

Are choroidal and CB nevi relatively vascular or avascular?

Back 15

AVASCULAR

Front 16

Why is this important to know?

Back 16

FA: decreased fluorescence.
a region of persistent choroidal hypofluorescence

Useful in identifying amelanocytic nevi

Melanomas are usually highly vascular

Front 17

What do the nevi cells look like?

Back 17

Atypical benign-looking melanocytes
i.e. Nevus cells are plumper than normal melanocytes of the CB and choroid.

Front 18

How many different types of UVEAL melanocytes are there?

Back 18

4

Front 19

What are the 4 types of uveal melanocyte cells?

Back 19

1) Plump polyhedral
2) Slender spindle
3) Plump fusiform & dendritic
4) Ballon cells

Front 20

Which is the most common type of the 4?

Back 20

PLUMP POLYHEDRAL

Front 21

Describe plump polyhedral melanocyte cells

Back 21

Most common type
Maximally pigmented
Majority of the cells in a "typical" nevus, are plump polyhedral melanocytes
MELANOCYTOMA (magnocellular nevus): nevus commposed exclusively of plump polyhedral melanocytes

Front 22

What is a MELANOCYTOMA?

Back 22

a nevus composed entirely of plump polyhedral melanocytes

Front 23

Which is the second most common type of UVEAL melanocyte?

Back 23

SLENDER SPINDLED

Front 24

What are SLENDER SPINDLED melanocytes?

Back 24

Nevus cells that contain little or NO pigment

Front 25

What are PLUMP FUSIFORM and DENDRITIC melanocytes?

Back 25

Less pigmented than PULM POLYHEDRAL
More pigmented than SLENDER SPINDLED
"Intermediate" pigmentation

Front 26

What are BALLOON melanocytes?

Back 26

Large cells
Abundant foamy cytoplasm

Front 27

What is CONGENITAL OCULAR or OCULODERMAL MELANOCYTOSIS?

Back 27

= A diffuse NEVUS of the uvea
Composed primarily of PLUMP POLYHEDRAL neus cells

Front 28

What effects do Choroidal & CB nevi have on adjacent tissue?

Back 28

1) Nevi may NARROW the overlying choriocapilaris. May rarely obliterate it
2) Slight degeneration, proliferation or reactive deposition by the RPE, may occur. In 40%, this induces overlying DRUSEN formation
3) May cause outer neural retinal changes. Usually minimal
4) Rarely, CENTRAL SEROUS CHOROIDOPATHY and SUBRETINAL NEOVASC. may occur

Front 29

Are UVEAL NEVI a precursor to anything?

Back 29

Precusor to most uveal MELANOMAS

Front 30

Are there in increase or decreased number of nevi in an eye that develops uveal melanoma?

Back 30

An INCREASE

Front 31

What are predictive factors for the progression of a uveal nevus to a uveal melanoma?

Back 31

1) SIZE: The greater the thickness of a choroidal nevus, the greater is the chance of it becoming a melanoma. Of nevi 2.5 mm in thickness, approximately 1% per month become melanomas
2) LOCATION: Nevi at the posterior portion of the eye more commonly become melanomas than those situated anteriorly
3) ORANGE PIGMENT: When choroidal nevi develop orange pigment on their surface, the chance of a melanoma developing greatly increases.
4) SEROUS FLUID: Serous fluid in the form of an overlying retinal detachment can be seen with nevi, but such nevi more likely become melanomas.
5) Hot spots on FA
6) SYMPTOMS (decreased vision or visual field defect).