Immunohistochemical profiling including beta-catenin in conjunctival melanocytic lesions.
Conjunctival melanocytic lesions encompass a group of clinically diverse, benign to malignant, neoplasms that may contain overlapping histopathological features, making definitive diagnosis challenging in some cases. In this series, we compared multiple immunohistochemical (IHC) markers in 11 conjunctival nevi, 10 primary acquired melanosis (PAM) lesions, and 11 conjunctival melanomas. Immunostains included the melanocytic markers HMB-45 and Melan-A, as well as the proliferative marker Ki-67. Loss of beta-catenin expression has been associated with more aggressive clinical disease in cutaneous melanoma, but its status in conjunctival melanocytic lesions is not known, therefore we incorporated beta-catenin immunohistochemical staining in our study. In this series, conjunctival melanomas had a higher Ki-67 proliferative index and HMB-45 immunoreactivity than did PAM lesions and conjunctival nevi (P<0.001). Melan-A was highly expressed in all 3 groups. Beta-catenin was more strongly expressed in melanomas and nevi than in PAM (P<0.001). There was high inter-grader reliability (Kappa=0.53). Overall, IHC labeling of HMB-45 and Ki-67 is increased in conjunctival melanomas compared to PAM or conjunctival nevi. Beta-catenin, an IHC marker previously unstudied in conjunctival melanocytic lesions, is not preferentially expressed in benign lesions and may play a different role in conjunctival atypia than it does in cutaneous melanoma.
Ophthalmic Plastic and Reconstructive Surgery, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, United States.
Harsha S
HS
Reddy
Department of Ophthalmology, University of Washington School of Medicine and Harborview Medical Center, Seattle, WA, United States; Department of Pathology, Division of Neuropathology, University of Washington School of Medicine and Harborview Medical Center, Seattle, WA, United States.
C Dirk
CD
Keene
Department of Ophthalmology, University of Washington School of Medicine and Harborview Medical Center, Seattle, WA, United States.
Shu H
SH
Chang
Department of Ophthalmology, University of Washington School of Medicine and Harborview Medical Center, Seattle, WA, United States.
Arash
A
Jian-Amadi
Department of Pathology, Division of Neuropathology, University of Washington School of Medicine and Harborview Medical Center, Seattle, WA, United States. Electronic address: pjjc@uw.edu.
Patrick J
PJ
Cimino
D049109:Cell Proliferation; D003230:Conjunctival Neoplasms / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D005819:Genetic Markers; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000235:genetics / Q000378:metabolism; D058965:MART-1 Antigen / Q000235:genetics / Q000378:metabolism; D008545:Melanoma / Q000235:genetics / Q000378:metabolism*; D058950:Melanoma-Specific Antigens / Q000235:genetics / Q000378:metabolism; D009508:Nevus, Pigmented / Q000235:genetics / Q000378:metabolism*; D012878:Skin Neoplasms / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*; D058951:gp100 Melanoma Antigen; D000096142:Cutaneous Malignant Melanoma
C495270:CTNNB1 protein, human; D005819:Genetic Markers; D019394:Ki-67 Antigen; D058965:MART-1 Antigen; D058950:Melanoma-Specific Antigens; C548637:PMEL protein, human; D051176:beta Catenin; D058951:gp100 Melanoma Antigen
Conjunctiva; Melanoma; Neoplasia; Primary acquired melanosis