|CONJUNCTIVAL LUMPS, BUMPS AND SPOTS
Thomas F. Freddo, O.D., Ph.D., F.A.A.O.
Professor and Vice-Chairman for Research
Department of Ophthalmology
Boston Medical Center
CONJUNCTIVA: Epithelium: Non-keratinized stratified epithelium with goblet cells. Continuous with that of cornea at limbus and with lid skin at muco-cutaneous junction.
Substantia Propria: Composed of loose (areolar) connective tissue including fibroblasts, occasional melanocytes, blood vessels, lymphatics, nerves and immunocompetent cells such as lymphocytes, plasma cells, mast cells, histiocytes, etc.
TRANSITION AREAS: Limbus and muco-cutaneous junction at lid margin prone to development (as are other transition areas) to development of viral-induced masses.
THINGS AT THE LIMBUS:
Limbal Dermoid: Congenital choristoma, usually non-cystic, straddling limbus and occasionally associated with Goldenhar's syndromewith auricular appendages and skeletal deformity.
Phlyctenule: Usually hypersensitivity response when at limbus, Can be associated with TB.
Bitot's spot: Squamous metaplastic change resulting in keratin formation on bulbar conjunctiva-associated with avitaminosis A. ERG for night blindness indicated.
Conjunctival Intraepithelial Neoplasia (CIN): Usually solitary, well-circumscribed lesions most often at the limbus which may exhibit leukoplakia. Most common in men between 40-70 years. Usually a long period of slow, intraepithelial growth. Direct invasion of the eye or orbit is rare, as are metastases. 20% recur; 95% within 2 years.
Epithelial inclusion cysts: Shape depends upon underlying tissue. Mechanism of formation, Determinants influencing color and contents.
Epithelial inclusion and other cysts: Smooth, rounded, often dome-shaped with conjunctival vessels passing over them. Caused either by trauma, surgery or foreign body if epithelial inclusion. Chronic inflammation may cause pseudo-retention cysts and retention cysts in the inferior fornix may represent blockage of duct of Glands of Krause.
Lymphangiectasis: dilated, tortuous clear or yellowish channels or accumulations of small, cystic spaces. Represent blockage of lymphatic channels usually in patients with chronic irritation. If hemorrhage occurs into these spaces it may mimic hemangioma.
Conjunctival granulomas: usually in palpebral conjunctiva or under lid skin near lid margin. Less often on bulbar conjunctiva. On biopsy usually represent non-caseating well-differentiated granulomas. In such cases the most likely cause is sarcoidosis.
Pyogenic granuloma: misnomer. The lesion is non-pyogenic and does not represent a granuloma. It is an exuberant healing response composed of granulation tissue (new vessels in a loose, edematous stroma with chronic inflammatory cells). usually follow surgery, retained foreign body or may occur secondary to rupture of tarsus by chalazia. Smooth surfaced, salmon-pink colored masses which bleed easily when manipulated.
Hemangiomas: congenital hamartomas. Capillary type usually occur in early childhood and may grow rapidly but usually undergo significant resorption by age 5. Cavernous hemangiomas- Usually not in children. Must be certain this is not anterior extension of orbital hemangioma.
Kaposi's Sarcoma: nodular mass varying in color from purplish-red to brown. In patients over 60 it usually occurs on the lower extremities and is associated with lymphoma. Likely of lymphatic endothelial origin. In younger individuals they occur on the trunk, neck and face including lids and should be taken as a sign of AIDS. This is rarely the presenting sign however. Those AIDS patients with HLADR5 phenotype are at increased risk.
TUMORS OF EPITHELIAL ORIGIN:
Papilloma: usually elevated, multi-lobulated with series of corkscrew, shaped vessels at center of each papillary frond. Most are pedunculated but sessile forms are not uncommon. Most commonly are seen at limbus or lid margin. Human papilloma virus 6 present in nuclei of most in children and young adults. Importantly, squamous cell CA may appear as a papillomatous mass and is also most common at the limbus.
Pedunculated in fornix Pedunculated or sessile at limbus
Spontaneously resolve Continue to grow
PIGMENTED TUMORS OF THE CONJUNCTIVA:
Guidelines: New pigmentation does NOT always mean malignancy (melanoma). Degree of pigmentation tells you nothing about behavior or malignant potential.
Pigmented masses arise from 3 cell types:
1. melanocytes 2. nevus cells 3. epithelial cells
FEATURE NEVUS CONGEN/MEL ACQUIRED/MELANOSIS
Onset Congenital Congenital Acquired
Structure Discrete Diffuse Diffuse
Color Brown Blue/Black Brown
Cysts 50% of cases None None
Pigment Variable Always Always
Moves Yes No Yes
Growth Stationary Stationary Wax and wane
involved No Heterochromia No
involved No in Nevus of Ota No
potential Conjunctiva Uvea or skin Conjunctiva
Melanoma of the Conjunctiva- Arise from 3 sources.
1. 20% from nevi (primarily nevocellular) 2. 40% from acquired melanosis 3. 40% de novo
Occur most often in middle-aged caucasians. Most often near the limbus. Those rarer tumors arising in palpebral conjunctiva generally have a less favorable prognosis. Characterized by slow superficial growth. Other than tumor thickness, few prognostic indicators for 5 yr survival available. Can't be classified according to Callender classification or Clark system used for skin melanomas.