Retinoblastoma – the malignant intraocular new growth developing from a neyroektoderma of a retina and which is found mainly at children of early age. Loss of the central and binocular sight, pain, a leykokoriya, development of squint, an ekzoftalm, secondary inflammation and glaucoma is characteristic of clinic of a retinoblastoma. Inspection at suspicion on a retinoblastoma includes a sight research, measurement of intraocular pressure, survey of an eye bottom, performing ultrasonography of an eye, a X-ray analysis of an orbit and additional bosoms of a nose, KT of a brain, a lyumbalny puncture. To patients with a retinoblastoma photocoagulation, cryotherapy of a tumor is carried out; at impossibility of preservation of an organ of vision - an enukleation of the affected eye with the subsequent glazoprotezirovaniye.
Retinoblastoma – the malignant new growth of children's age which is affecting a retina, a vascular cover of an eye, an orbit and often giving the remote metastasises. 2,5-4,5% of cases of all malignant new growths at children up to 15 years fall to the share of a retinoblastoma. In most cases the retinoblastoma develops aged up to 5 years, the peak of incidence falls on 2-3 years. In ophthalmology the tumor with an identical frequency occurs at girls and boys.
In 50-60% of cases of a retinoblastoma have a genetic (congenital) origin. More than a half of children with a retinoblastoma is born from the parents who had a similar disease in the childhood. The congenital retinoblastoma usually comes to light at children aged up to 30 months. In this case the retinoblastoma is, as a rule, combined with other congenital anomalies – heart diseases, sky crevices ("a wolf mouth"), to kortikalny nurseries giperostozy, etc. Patients with a genetic form of a retinoblastoma have an increased risk of development of malignant new growths of other localization.
Sporadic cases of a retinoblastoma meet less often and arise for the unknown reasons. It is accepted to refer high age of parents, their employment on metallurgical productions to number of risk factors of not genetic form of a retinoblastoma, the adverse ecological and alimentary factors causing aberrations in chromosomes retinalny and gametes. This form of a tumor is shown at children of more advanced age and is extremely rare - at adults.
Modern views on a histogenesis of a retinoblastoma allow to carry it to tumors of a neyroektodermalny origin. The retinoblastoma can proceed from cages of any nuclear (granular) layer of a retina. At a microscopic research lack of a stroma, the centers of a necrosis and a kaltsifikata, different degree of a differentiation of tumor cells are defined.
Rapid growth, metastasis on an optic nerve in a brain, and also hematogenic distribution to marrow and tubular bones is characteristic of a retinoblastoma.
Classification of a retinoblastoma
By origin retinoblastomas share on hereditary and sporadic. Hereditary retinoblastomas usually affect at the same time both eyes. Sporadic retinoblastomas, as a rule, affect one eye and develop locally, with formation of single (unilateral) tumoral knot.
On degree of a difyoferentsirovka of tumor cells distinguish the differentiated tumor form – retinotsity and an undifferentiated form – a retinoblastoma which meets more often and is more malignant.
The retinoblastoma can have endofitny type of growth in the direction of the center of an eyeball: at the same time there is a destruction of layers of a retina and vitreous body. At other option of growth – ekzofitny, the retinoblastoma infiltrirut a retina, extending in subretinalny space. Ekzofitny tumors can cause an otsloyka of a retina and a congestion of a transsudat in subretinalny space. In rare instances (1-2%) the infiltrative form of a retinoblastoma which leads to diffusion thinning of a retina, accumulation of exudate in forward departments of an eye, development of forward solderings and a pseudo-hypopeony meets.
According to clinical classification of a retinoblastoma by the TNM system, allocate extents of development of primary tumor:
- T1 – the retinoblastoma occupies up to 25% of an eye bottom
- T2 – a retinoblastoma extends to the area more than 25%, but less than 50% of a surface of a retina
- TZ – a retinoblastoma extends more than to a half of a retina or goes beyond its limits, but keeps an intraocular arrangement
- T4 – a retinoblastoma goes beyond an orbit.
- N1 – are available metastasises in regionarny (parotid, submaxillary, cervical) lymph nodes.
- Ml - are defined the remote metastasises of a retinoblastoma in a brain, marrow, bones, a liver, etc. bodies.
In a clinical current of a retinoblastoma distinguish four consecutive stages.
I – rest stage. In this period subjective symptoms are absent. At survey of the affected eye the leykokoriya (a symptom of "a cat's eye") – the white pupillary reflex caused by raying of tumoral weight through a pupil comes to light. Refer loss of the central and binocular sight to early signs of a retinoblastoma owing to what squint can develop.
II – a glaucoma stage. Is followed by the inflammatory phenomena in an eye – hyperaemia, a photophobia, dacryagogue, development of an iridotsiklit and uveit. Against the background of a tumoral invasion the local pain syndrome is noted. Destruction by a retinoblastoma of the trabekulyarny device leads to difficulty of outflow of VGZh, increase in intraocular pressure and developing of secondary glaucoma.
III - a germination stage. It is characterized by development of an ekzoftalm of various degree of expressiveness, an invasion of soft fabrics of an orbit and destruction of its walls, germination of a retinoblastoma in additional bosoms and subarakhnoidalny space.
IV – metastasis stage. Proceeds with identification of the remote disseminirovanny centers in marrow, a liver, tubular bones, a brain, skull bones. Distribution of a retinoblastoma happens on a soft brain cover, an optic nerve, a limfogenny and hematogenic way. At this stage the general condition of the patient suffers: intoxication, weakness, brain symptoms (nausea, vomiting, a headache) develops.
Diagnostics of a retinoblastoma
Children with the family anamnesis of a retinoblastoma have to be under constant observation of the ophthalmologist. Development of a retinoblastoma is usually indicated by a triad of symptoms: a leykokoriya, squint, expansion of a pupil with weakening of its reaction to light. At emergence of these signs the careful ophthalmologic examination of the child including biomicroscopy, a direct and return oftalmoskopiya, a vizometriya, a tonometriya, a gonioskopiya, a research of binocular sight, an ekzoftalmometriya, measurement of a corner of squint is conducted. At turbidity of optical environments the important role in identification of a retinoblastoma belongs to ultrasonography of an eye.
The intraocular biopsy can lead to a dissemination of malignant cages in an eye therefore resort to its carrying out only in the presence of absolute indications. For assessment of prevalence of a retinoblastoma the orbit X-ray analysis, a X-ray analysis of okolonosovy bosoms, brain KT and MPT, a liver stsintigrafiya, an osteostsintigrafiya are used. For assessment of possible remote metastasis resort to performance of a lyumbalny puncture with a research of tserebrospinalny liquid; punctures of marrow and to a research of a miyelogramma.
In the course of diagnostics the retinoblastoma should be differentiated from a cicatricial retinopathy, a retina dysplasia, gamarty, myagkotkanny sarcomas, metastasises of a neuroblastoma, defeats of an orbit at a lymphoma and leukemia.
Treatment of a retinoblastoma
Treatment of a retinoblastoma is carried out taking into account a stage of tumoral defeat. At the same time surgical intervention, beam and medicinal chemotherapy, a lazerkoagulyation, cryotherapy, thermotherapy can be used. The correct combination of these methods in many cases allows to keep an eye and sight. In couples a bilateral retinoblastoma, concerning each eye the differentiated tactics depending on extent of its defeat is defined by a tumor.
Now oftalmokhirurg and oftalmoonkolog seek to adhere to the most conservative maintaining a retinoblastoma. At defeats of the forward site of a retina and diameter of a tumor to 7 mm resort to cryodestruction of a retinoblastoma; at defeat of back departments and the sizes of a tumor to 4 mm photocoagulation is shown. Performing thermotherapy – complex impact on a tumor by means of microwave therapy, ultrasonic and infrared radiation is possible.
At massive intraocular damage, development of glaucoma, loss and impossibility of restoration of sight resort to an eye enukleation with the subsequent glazoprotezirovaniye. At ekstraokulyarny distribution of a retinoblastoma the eye-socket ekzenteration is shown.
The retinoblastoma is extremely sensitive to beam treatment. Radiation therapy at a retinoblastoma allows to achieve good results in combination with organ-preserving and surgical methods of treatment. At the same time it is possible both external remote, and contact radiation by means of applications of radioactive materials. Development of a post-beam cataract, a beam keratit, kseroz can be a complication of radiation therapy.
The chemotherapy in treatment of a retinoblastoma is used at massive intraocular damage, a tumoral invasion of an optic nerve, regional metastasises. The combination of several tsitostatik is recognized as the most effective (a vinkristina, an etopozida, a karboplatina).
Forecast and prevention of a retinoblastoma
At timely diagnostics and identification of a retinoblastoma at an early stage perhaps permanent treatment of the patient by means of organ-preserving methods – photocoagulations, cryotherapies, radiation therapy. At an eye enukleation high survival is also observed, however this operation is followed by loss of an eye as organ of vision and formation of cosmetic defect. As factors of the adverse forecast of a retinoblastoma serve germination of a tumor in an optic nerve, the invasion of a horioidalny cover, ekstraskleralny spread of a tumor, bilateral defeat.
Prevention of a retinoblastoma requires medico-genetic consultation of families with hereditary cases of cancer of retina, inspection of children of early age from risk groups.