Orbital and Ocular Tumors
Benign tumors can develop from infancy and grow rapidly or slowly and present themselves in later life. Some benign tumors are superficial and are easily identifiable by external presentation, palpation, and x-rays, but some are deep and may require a CT scan for a more thorough and precise diagnosis. There can be a significant proptosis, and visual function may be jeopardized. Be-nign tumors are masses characterized by the lack of infiltration in the surrounding tissues. Examples are cystic dermoid cysts and mucocele, hemangiomas, lymphangiomas, lacrimal tumors, and neurofibromas.
To prevent recurrence, benign masses are excised completely when possible. Sometimes, excision is difficult because of the in-volvement of some portions of the orbital bones, such as deep dermoid cysts, in which dissection of the bone is required. Sub-total resection may be indicated in deep benign tumors that intertwine with other orbital structures, such as optic nerve meningiomas. Complete removal of the tumor may endanger visual function.
Benign tumors include a wide variety of neoplasms and increase in frequency with age. Nevi may be unpigmented at birth and may enlarge and darken in adolescence or may never acquire any pigment at all. Hemangiomas are vascular capillary tumors that may be bright, superficial, strawberry-red lesions (ie, strawberry nevus) or bluish and purplish deeper lesions. Milia are small,white, slightly elevated cysts of the eyelid that, when in multiples, create a blemish. Xanthelasma are yellowish, lipoid deposits on both lids near the inner angle of the eye that commonly appear as a result of the aging of the skin or a lipid disorder. Molluscum contagiosum lesions are flat, symmetric growths along the lid margin caused by a virus that can result in conjunctivitis and ker-atitis after debris gets into the conjunctival sac.
Treatment of benign congenital lid lesions is rarely indicated, except when visual function is affected. Corticosteroid injection to the hemangioma lesion is usually effective, but surgical excision may be performed. Benign lid lesions usually present aesthetic problems rather than visual function problems. Surgical excision, or electrocautery, is primarily performed for cosmetic reasons, except for cases of molluscum contagiosum, for which surgical in-tervention is performed to prevent an infectious process that may ensue.
Conjunctival nevus, a congenital, benign neoplasm, is a flat, slightly elevated, brown spot that becomes pigmented during late childhood or adolescence. This should be differentiated from the pigmented lesion melanosis acquired at middle age, which tends to wax and wane and become malignant melanoma. Keratin- and sebum-containing dermoid cysts are congenital and can be found in the conjunctiva. Dermolipoma is a congenital tumor that man-ifests as a smooth, rounded growth in the conjunctiva near the lateral canthus. Papillomas are usually soft with irregular surfaces and appear on the lid margins. Treatment consists of surgical excision.
Rhabdomyosarcoma is the most common malignant primary or-bital tumor in childhood, but it can also develop in elderly per-sons. The symptoms of rhabdomyosarcoma include sudden painless proptosis of one eye followed by lid swelling, conjuncti-val chemosis, and impairment of ocular motility. Imaging of these tumors establishes the size, configuration, location, and stage of the disease; delineates the degree of bone destruction; and is useful in estimating the field for radiation therapy, if needed. The most common site of metastasis is the lung.
Management of these primary malignant orbital tumors involves three major therapeutic modalities: surgery, radiation therapy, and adjuvant chemotherapy. The degree of orbital destruction is important in planning the surgical approach. In the orbit, resec-tion often involves removal of the globe. The psychological needs of the patient and family, especially the parents of a pe-diatric patient, are paramount in planning the management approach.
Basal cell carcinoma is the most common malignant tumor of the eyelid. Squamous cell carcinoma occurs less frequently but is con-sidered the second most common malignant tumor. Malignant melanoma is rare. Malignant eyelid tumors occur more frequently among people with fair complexion who have a history of chronic exposure to the sun.
Basal cell carcinoma appears as a painless nodule that may ul-cerate. The lesion is invasive, spreads to the surrounding tissues, and grows slowly but does not metastasize. It usually appears on the lower lid margin near the inner canthus with a pearly white margin. Squamous cell carcinoma of the eyelids may resemble basal cell carcinoma initially because it also grows slowly and painlessly. It tends to ulcerate and invade the surrounding tis-sues, but it can metastasize to the regional lymph nodes. Malig-nant melanoma may not be pigmented and can arise from nevi. It spreads to the surrounding tissues and metastasizes to other organs.
Complete excision of these carcinomas is followed by recon-struction with skin grafting if the surgical excision is extensive. The ocular postoperative site and the graft donor site are moni-tored for bleeding. Donor graft sites may include the buccal mu-cosa, the thigh, or the abdomen. The patient is referred to an oncologist for evaluation for the need for radiation therapy treat-ment and monitoring for metastasis. Early diagnosis and surgical management are the basis of a good prognosis. These conditions have life-threatening consequences, and surgical excisions may re-sult in facial disfigurement. Emotional support and reassurance are important aspects of nursing management.
Conjunctival carcinoma most often grows in the exposed areas of the conjunctiva. The typical lesions are usually gelatinous and whitish due to keratin formation. They grow gradually, and deep invasion and metastasis are rare. Malignant melanoma is rare but may arise from a preexisting nevus or acquired melanosis during middle age. Squamous cell carcinoma is also rare but invasive.
The management is surgical incision. Some benign tumors and most malignant tumors recur. To avoid recurrences, patients usu-ally undergo radiation therapy and cryotherapy after the excision of malignant tumors. Cosmetic disfigurement may result from extensive excision when deep invasion by the malignant tumor is involved.
A malignant tumor of the retina, retinoblastoma, occurs in child-hood, is hereditary, and requires complete enucleation if there is to be a chance for successful outcome. Another cancer that primarily occurs in adults is ocular melanoma. This rare, malignant choroidal tumor is often discovered on a retinal examination. In its early stages, it could be mistaken for a nevus. Many ophthalmologists may practice for decades and never encounter this lesion. For this reason, any patient who is suspected of having ocular melanoma should be immediately referred to an ocular oncologist with ex-perience in this disease.
Although many patients do not have symptoms in the early stages, some patients complain of blurred vision or a change in eye color. A number of such tumors have been found in people with blindness who have painful eyes. In addition to a complete physical examination to discover any evidence of metastasis (to the liver, lung, and breast), retinal fundus photography, fluorescein angiography, and ultrasonography are performed. The diagnosis is confirmed at biopsy after enucleation.
Tumors are classified according to size (ie, small, medium, and large). Very small tumors are generally monitored, whereas medium and large tumors require treatment. Treatment consists of radia-tion, enucleation, or both. Radiation therapy is achieved by external beam performed in repeated doses over several days or through the surgical implantation of a radioactive plaque, which is removed after several days.