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.
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