Definition

The orbital area is the skull cavity where the eyeballs and surrounding tissues are located. These tissues include eye muscles, blood vessels, eye nerves, tear glands, and fatty tissue. The orbital cavity, composed of skull bones, protects the eyeball and other orbital tissues.

The orbital area is pear-shaped, with the widest opening at the front and narrower at the back. If a lesion or abnormal growth occurs in this relatively small area, it increases orbital cavity volume, causing proptosis (protrusion of the eyeball), affecting the eye muscles and vision.

Orbital tumors are abnormal growths in the tissues within the orbital cavity. They can be benign or malignant. The tumors may originate from the orbital tissue itself or metastasize from other parts of the body.

Types of orbital tumors include cysts, vascular tumors, lymphoma, neurogenic tumors of the nerves, and secondary tumors that metastasize from the sinus cavity or skull cavity around the eyes.

Causes

Primary orbital tumors, though rare, can be benign or malignant. Abnormal growth can occur in every orbital structure. Tumors can also metastasize from adjacent parts of the body, causing pressure on the orbital cavity.

Capillary hemangiomas represent the most prevalent orbital tumors observed in pediatric patients. These benign tumors, encapsulated by layers of blood vessels, are typically identified either at birth or within the first three months of life. Capillary hemangiomas can increase in size over time. Other benign orbital tumors in children include dermoids, lymphangiomas, and histiocytic tumors.

Rhabdomyosarcoma and mesenchymal tumors are the leading malignant orbital tumors in children, originating within the orbital cavity. These aggressive tumors predominantly manifest in children under the age of two or over the age of six, and are frequently located in the orbital region near the posterior part of the nose.

Metastatic orbital tumors that more commonly affect children include neuroblastoma, Ewing's sarcoma, Wilms' tumor, and leukemia. Other malignant tumors observed in this population include Burkitt's lymphoma and granulocytic sarcoma.

In adults, cavernous hemangioma is identified as the most common orbital tumor. In a CT scan, this tumor appears round, encapsulated, and well-defined borders. Histological examination reveals large blood-filled spaces lined with blood vessels and smooth muscle. These tumors generally respond well to treatment and are quite tolerated by patients, except in cases where visual acuity or visual fields are compromised.

Risk Factor

Several risk factors can contribute to the development of orbital tumors:

• Abnormal eye development. Children born with abnormalities affecting any part of their bodies, including their eyes, are at increased risk of orbital tumors.
• Thyroid eye disease. Individuals with Grave's disease, an autoimmune condition affecting the thyroid gland, have an elevated risk of orbital tumor development.

Symptoms

Orbital tumors can manifest with varying symptoms. Sometimes patients are asymptomatic at the early stage, and symptoms may evolve gradually over time. In other patients, the symptoms occur suddenly. The nature and location of symptoms often provide important diagnostic clues distinguishing between benign and malignant tumors.

Many patients show symptoms of eyeball protrusions (proptosis or exophthalmos) due to pressure within the orbit, resulting in difficulty fully closing the eyelids and leading to dryness and irritation of the eye's outer membrane.

Some tumors are also visible or palpable upon examination. Others can cause visual disturbances such as decreased vision, temporary loss of vision, or double vision.

Evaluation of patients suspected of having orbital tumors begins with a thorough history of related vision symptoms and comprehensive medical background. Key considerations include the duration and progression rate of symptoms. Symptoms such as pain, double vision, pulsatile sensations, and visual acuity impairment warrant particular attention. Additionally, a history of trauma or familial predisposition to orbital tumors can aid in diagnosis.

Clinical examination of the eyes involves detailed inspection of orbital structures to see the abnormalities under adequate lighting conditions. Identification of signs such as hypertelorism (increased distance between the eyes), proptosis, eyelid swelling and bruising, and dilation of blood vessels in the eye's cornea. Assessment for blepharoptosis (drooping of the upper eyelid) and lagophthalmos (incomplete eyelid closure) are other signs that should be observed. Proptosis, or exophthalmos, signifies significant orbital pathology and requires thorough investigation.

Palpation of the anterior orbit to assess tenderness, consistency, and mobility of the tumor. Tenderness may indicate inflammation or nerve compression, as seen in adenoid cystic carcinoma affecting the lacrimal glands.

Evaluation of lymph nodes and blood vessels surrounding the orbit to detect abnormal pulsations indicative of vascular anomalies or herniation of cranial contents through orbital bone defects, as observed in encephaloceles.

Auscultation using a stethoscope can detect abnormal orbital or intracranial blood flow. Suspected tumors with increased vascularity may necessitate arteriography for precise evaluation.

Ophthalmic assessments should meticulously evaluate visual acuity, pupillary responses, ocular motility, and presence of diplopia. Measurement of intraocular pressure, slit lamp examination for eyelid bruising and vascular enlargement, and funduscopy to detect optic nerve cupping, retinal detachment, choroidal folds, and neovascularization pathways are essential components of diagnostic evaluation.

Diagnosis

Careful examination by an ophthalmologist is crucial for diagnosing orbital tumors. The physician evaluates symptoms and conducts a thorough assessment of visual function and the structural integrity of orbital components. If necessary, diagnostic imaging studies such as ultrasound, CT scans, and MRI are recommended for comprehensive evaluation.

Most orbital tumors exhibit characteristic features on examination, necessitating the need for biopsy in many cases. However, biopsy may be required under specific circumstances to ascertain the tumor type.

Laboratory Examination

Laboratory tests are conducted when physical examination suggests the presence of an orbital tumor.

Imaging Studies

CT scan is the primary imaging modality for orbital tumors, offering detailed evaluation of tissue and bone, particularly in the orbital region. Contrast-enhanced CT scans facilitate visualization of inflammatory processes and vascular tumors.

MRI excels in soft tissue characterization, including orbital structures, although CT scans provide superior assessment of orbital bone integrity. Ocular ultrasound assesses anterior and mid-orbital lesions, while Doppler ultrasound evaluates orbital vasculature and blood flow.

Fine Needle Aspiration Biopsy (FNAB) is a diagnostic procedure for obtaining tumor cell samples using a fine needle, distinguishing benign from malignant tumors with high accuracy. FNAB, combined with clinical and radiological findings, leads to correct diagnosis in 80% of cases. Open biopsy is employed when FNAB yields insufficient tissue, allowing for comprehensive tissue-level diagnosis despite increased discomfort and costs.

Other Tests

Genetic analysis aids in tumor characterization. Staging employs TNM criteria from the American Joint Committee on Cancer (AJCC), categorizing tumors based on tumor size (T), lymph node involvement (N), and metastasis (M) into stages I-IV.

Management

Medical Treatment

Treatment is tailored to biopsy or surgical findings. Some conditions, like orbital cellulitis, respond well to medical therapy with antimicrobial agents. Surgical intervention becomes necessary in cases of treatment-resistant or deteriorating conditions. Orbital inflammatory diseases (pseudotumors) are typically managed with steroid medications. Non-surgical treatments, such as steroid injections, are effective for conditions like capillary hemangiomas.

Surgery

Surgical approach depends on tumor location and size. Orbitotomy, performed via periorbital or intraocular routes, allows access for tumor removal.

Complications

Complications associated with orbital tumors include dryness and irritation of the eyes, resulting from incomplete eyelid closure in patients with eye protrusion (proptosis or exophthalmos).

The most serious surgical complication is vision loss, which can occur due to excessive pressure on the eyeball and compression of the central retinal artery. Intraoperative and postoperative bleeding, as well as pressure on the optic nerve and central retinal artery obstruction, are additional risks.

Diplopia (double vision) can result from damage to the eye muscles or nerves, while paresthesia or paralysis of the eye muscles may occur if the optic nerve is injured.

Prevention

Currently, there are no established methods to prevent orbital tumors. Prompt and accurate diagnosis and treatment are crucial in preventing symptom exacerbation and complications.

When to See a Doctor?

Seek immediate consultation with an ophthalmologist if you exhibit any signs or symptoms of an orbital tumor to ensure appropriate treatment.

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