ASOPRSFall Scientific SymposiumSyllabus
142
ASOPRSThesis&Awards Session
Moderators:Michael T.Yen,MD, Roberta E. Gausas,MD
4:30pm
Clinical and Immunohistochemical Features of ConjunctivalMelanocytic Lesions
HarshaS. Reddy,MD
Introduction:
Melanocytic conjunctival lesionsmay overlap in clinical presentation and histopathology but varywidely in clinical
course and prognosis. Immunohistochemistry (IHC) has been used to distinguish between these lesions.This study evaluates IHC
differences between conjunctival nevi, primary acquiredmelanosis (PAM), and conjunctival melanomas using themarkers HMB-45,
Ki-67,Melan-A and a novel marker, beta-catenin, a protein of theWnt signaling pathway. In cutaneousmelanomas, loss of
beta-catenin expression is associatedwithmore aggressivemolecular and clinical disease.
Methods:
11 conjunctival nevi, 10PAM lesions, and 10 conjunctival melanomaswere identified using a retrospective review
by ICD code and the institutional pathology database between the dates of 1/2000 and 1/2010. Each specimenwas sectioned and
stained for the 4 IHCmarkers noted above.Three 3 independent graders trained in ocular pathology and blinded to the diagnosis
scored each slide for staining uniformity (0=no staining, 1=focally positive, 2=variably positive, 3=uniformly positive) and intensity
(0=no staining, 1=weak, 2=intermediate, 3=uniformly positive).The 3 groups’ IHC staining patternswere statistically compared.
Results:
Therewas good inter-rater reliability (Kappa 0.53). HMB-45 and Ki-67 had higher staining intensity and distribution scores
in conjunctival melanomas than in PAM and conjunctival nevi (p< 0.001).Melan-Awas highly expressed in all 3 groups and did not
distinguish between groups. Beta-cateninwasmore strongly expressed inmelanomas and nevi than in PAM (p< 0.001).
Conclusion:
IHC labeling of HMB-45 and Ki-67 is stronger in conjunctival melanomas than in PAM or conjunctival nevi.
Beta-catenin, an IHCmarker previously unstudied in conjunctival melanocytic lesions, is not preferentially expressed in benign lesions
andmay play a different role in conjunctival atypia than it does in cutaneousmelanoma.
References:
1. Shields CL,Markowitz JS, Belinsky I et al. Conjunctival melanoma: outcomes based on tumor origin in
382 consecutive cases. Ophthalmol 2011; 118:389-95. 2. Jakobiec FA, Bhat P, Colby KA. Immunohistochemical studies of
Conjunctival nevi andmelanomas.ArchOphthal 2010; 128(2):174-183. 3. ShararaNA,Alexander RA, Luthert PJ, et al. Differential
immunoreactivity of melanocytic lesions of the conjunctiva. Histopathology. 20001; 39(40):426-431. 4. Keijser S,MissottenGS,
Bonfrer JM et al. Immunophenotypicmarkers to differentiate between benign andmalignant melanocytic lesions. BJO 2006; 90:213-
217. 5. Lebe B, Pabuccuoglu U, Ozer E.The significance of Ki-67 proliferative index and cyclinD1 expression of dysplastic nevi in
the biologic spectrum of melanocytic lesions.Appl ImmunohistochemMol Morphol 2007; 15(2):160-164. 6.ChienAJ,Moore EC,
Lonsdorf AS, et al.ActivatedWnt/betacatenin signaling inmelanoma is associatedwith decreased proliferation in patient tumors and
amurinemelanomamodel. Proc Natl Acad Sci USA 2009; 106:1193–1198. 7.KageshitaT, Hamby CV, IshiharaT, et al. Loss of beta-
catenin expression associatedwith disease progression inmalignant melanoma. Br J Dermatol 2001; 145:210–216.
DetailedProgram
—Friday,October 17, 2014
