Agents can predispose tissue to tumors of epithelial, melanocytic, stromal origins
Among the tumors that may develop in the conjunctiva of pediatric patients, most are epithelial and melanocytic in origin.
Reviewed by Jacob J. Pe’er, MD
Clinicians know the conjunctiva to be a thin, translucent, vascularized mucous membrane comprised of numerous elements, said Jacob J. Pe’er, MD. Because the tissue is external, it is exposed to chemical, physical, and biologic agents that can predispose the tissue to tumors of epithelial, melanocytic, and stromal origins. The vast majority of tumors in children arise from the first two.
“Most conjunctival tumors in children are rare and usually benign and include epithelial tumors, such as squamous papillomas and nevi,” said Dr. Pe’er, the Jonas Friedenwald Professor of Ophthalmic Research, Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem.
“The rare malignant tumors, such as melanoma and lymphoma, are usually larger and develop in older children,” he added. “Xeroderma pigmentosa may cause malignant conjunctival tumors in children.”
Evaluation of patients who present with a conjunctival abnormality includes an external ocular examination, slit lamp examination, fluorescein or rose bengal staining, documentation by drawing or photography, and histopathologic diagnosis.
Benign epithelial tumors
Most of the benign tumors are squamous papillomas and epithelial cysts. The former occur frequently in children in association with the papilloma virus, are solitary but can be bilateral and multifocal, and often are asymptomatic except when they enlarge, when they can cause a foreign-body sensation, mucous secretion, hemorrhagic tears, and incomplete eyelid closure. Treatment is observation or cryotherapy.
When multiple lesions are present, recurrence of the papillomas is common; recurrences are treated with topical or systemic interferon alpha-2b, topical mitomycin C, or cimetidine, according to Dr. Pe’er.
Conjunctival epithelial cysts-which can be congenital or acquired, the latter of which are more common-are mostly epithelial inclusion cysts that develop spontaneously or after trauma or non-surgical trauma. The cysts are observed if they are asymptomatic and removed if they enlarge or become symptomatic. Most cysts resolve spontaneously over time.
Benign melanocytic tumors
Among these, the junctional nevus develops almost exclusively in children and adolescents. According to Dr. Pe’er, other growths, such as the compound nevus, the inflamed juvenile conjunctival nevus, and congenital melanosis, and racial melanosis, which fall under this classification, are not actual tumors.
Conjunctional junctional nevi
Conjunctional junctional nevi are noteworthy in that they are the only stage that appear in children and young adolescents, and they appear primarily in the bulbar juxtalimbal conjunctiva. They can be misdiagnosed as primary acquired melanosis, which develops only in adults. These appear as focal, flat, well-circumscribed lesions that move freely over the ocular surface. Treatment is periodic observation and excision upon enlargement.
Inflamed juvenile conjunctival nevi
Inflamed juvenile conjunctival nevi are important considerations in young patients. These are compound nevi that appear only in children and young adolescents. The nevi look inflamed; most are amelanotic and related to symptomatic or asymptomatic conjunctival allergy. The nevi may be worrisome with rapid growth and congestion.
Congenital melanosis oculi, oculodermal melanocytosis
These are not actual tumors, but they must be considered because of the potential for development of uveal melanoma.
These tumors can be both benign and malignant. Among them, the two main types are pyogenic granulomas and various types of vascular anomalies, such as hemangiomas. Pyogenic granulomas can appear after surgery. Of the fibrous tumors, which include fibromas, fibrous histiocytomas, which are benign in children, and nodular fasciitis, benign fibrous histiocytomas can present in the pediatric population.
Histiocytic tumors include juvenile xanthogranuloma, which can be difficult to treat, Dr. Pe’er said. Rhabdomyosarcoma is a form of myogenic tumor that can be associated with the orbital manifestation of the disease. Juvenile conjunctival xanthogranuloma appears as a single orange-pink stromal mass that often develops near the limbus.
Histopathologic evaluation shows histiocytes and Touton giant cells; this tumor may resolve spontaneously. Treatment can include excision, administration of local or systemic corticosteroids, and brachytherapy. Other tumor types are lipomatous tumors and lymphoproliferative tumors. The former include herniation orbital fat that are not uncommon. In children, the latter include usually benign reactive lymphoid hyperplasia, rare usually lowgrade lymphoma that can be diagnosis by immunohistochemistry and molecular pathology.
Hamartomas and choristomas usually are diagnosed first in children and include dermoids, dermolipomas, osseous choristomas, lacrimal gland choristomas, and complex choristomas. These are congenital lesions that are treated based on their size and any resulting functional disturbance. Caruncular tumors arise from both the conjunctival tissue and from the epidermis and skin appendages.
Xeroderma pigmentosa, which is characterized by extreme sensitivity to sunlight, is inherited as an autosomal recessive trait with full penetrance. The disease occurs alone as the result of a mutation in one of eight genes involved in nucleotide excision repair. The eyes are involved in about 20% of cases and the involvement is limited to eyelids, conjunctiva, and cornea exposed to the sun.
Dr. Pe’er noted that the most relevant factor is that the patient is predisposed to develop multiple neoplasms of the eyelid and ocular surface, such as basal cell and squamous cell carcinoma and melanoma.
Jacob J. Pe’er, MD
This article was adapted from Dr. Pe’er’s presentation during Cornea Subspecialty Day at the 2018 meeting of the American Academy of Ophthalmology. Dr. Pe’er has no financial interests to disclose related to this report.