The retinoblastoma is a rare, malignant tumour of immature retina cells in the eye which is almost found in the childhood (usually until 5 years), caused by a hereditary genetic defect or non-heritable mutation.
The bilateral retinoblastoma, when both eyes are affected is developing from a hereditary genetic defect. Unilateral retinoblastoma affects only one eye and is almost caused by mutation on chromosomes.
Main signs of retinoblastoma
One of early signs of a tumour is his abnormal appearance called “cat’s eye” or “white eye” (medical term is leukocoria). Parents describe this symptom as an unusual luminescence in two or one eye.
Sometimes this symptoms include deterioration of vision and children develop a squint caused by a tumour. It is commonly referred as “cross-eyed” or “wall-eyed”. Unfortunately, small children cannot explain something and the squint is noticed after it is grown large and the vision binocular sight.
The late diagnosis is also explained by that fact that intraocular tumours are painless. Pain can occur only at red and irritated eye with glaucoma (increase of intraocular pressure). Other signs can be delayed growth and development.
How does retinoblastoma grow and spread
If retinoblastoma is not treated it can grow and can form other tumours in the eyeball and other surrounding parts. These tumours can block the circulation of the fluid inside the eye and the pressure in the eye increases. The result is painful and irritated eye with glaucoma and loss of vision.
Fortunately, most retinoblastomas are diagnosed and treated before they have spread outside the eyeball. Because malignant cells can also spread to other parts of the body. The retinoblastoma cells sometimes spread along the optic nerve and reach the brain.
Retinoblastoma cells can also spread to the covering layers of the eyeball and into the eye socket, eyelids, and surrounding tissues. If tissues outside the eyeball are affected, the cancer can also spread to lymph nodes (small bean-shaped collections of immune system cells) and to other organs of the body such as the liver, bones, and bone marrow (the soft, inner part of many bones).
Staging of retinoblastoma
Definition of retinoblastoma staging is important for choosing treatment and outcome.
There are some stages classified by how far cancer has spread, for example:
- intraocular retinoblastoma (inside the eye);
- extra ocular retinoblastoma (outside the eye);
- damage of an optical nerve;
- orbital retinoblastoma;
- metastatic retinoblastom
How is retinoblastoma diagnosed?
Retinoblastoma can be found by physical exam and imaging tests and treatment can begin without a biopsy (a sample of tumour is removed). Biopsy cannot be done without harming the eye and risking spreading cancer cells outside the eye. Retinoblastoma can be also diagnosed by doctors who have experience with this disease.
The part of diagnostic procedures is performed under general anaesthesia.
Following imaging tests can be included:
- Computed tomography (CT) scan;
- Magnetic resonant imaging (MRI) scan;
- Lumbar puncture (spinal tap)
- Bone marrow aspiration and biopsy