mart-1-antigen and Conjunctival-Diseases

To review the diagnostic categories of a group of conditions referred to as "primary acquired melanosis.". Literature review on the subject and proposal of an alternative diagnostic schema with histopathologic and immunohistochemical illustrations.. Standard hematoxylin-eosin-stained sections and immunohistochemical stains for MART-1, HMB-45, microphthalmia-associated transcription factor (MiTF), and Ki-67 for calculating the proliferation index are illustrated.. "Melanosis" is an inadequate and misleading term because it does not distinguish between conjunctival intraepithelial melanin overproduction ("hyperpigmentation") and intraepithelial melanocytic proliferation. It is recommended that "intraepithelial melanocytic proliferation" be adopted for histopathologic diagnosis. Atypical proliferations are characterized either by bloated dendritic melanocytes with enlarged cell components (dendrites, cell bodies, and nuclei) or by epithelioid melanocytes without dendrites. Atypical polygonal or epithelioid pagetoid cells may reach higher levels of the epithelium beyond the basal layer. Immunohistochemistry defines the degree of melanocytic proliferation or the cellular shape (dendritic or nondendritic) (MART-1, HMB-45) or identifies the melanocytic nuclei (MiTF). Intraepithelial melanocytic proliferation without atypia represents increased numbers of normal-appearing dendritic melanocytes (hyperplasia or early neoplasia) that generally remain confined to the basal/basement membrane region. Intraepithelial nonproliferative melanocytic pigmentation signifies the usually small number of conjunctival basal dendritic melanocytes that synthesize increased amounts of melanin that is transferred to surrounding keratinocytes.. All pre- and postoperative biopsies of flat conjunctival melanocytic disorders should be evaluated immunohistochemically if there is any question regarding atypicality. This should lead to a clearer microscopic descriptive diagnosis that is predicated on an analysis of the participating cell types and their architectural patterns. This approach is conducive to a better appreciation of features indicating when to intervene therapeutically. An accurate early diagnosis should forestall unnecessary later surgery.

Topics: Biomarkers; Conjunctival Diseases; Conjunctival Neoplasms; gp100 Melanoma Antigen; Humans; Immunohistochemistry; Ki-67 Antigen; MART-1 Antigen; Melanoma-Specific Antigens; Melanosis; Microphthalmia-Associated Transcription Factor; Nevus, Pigmented; Terminology as Topic

Recent studies indicate that WT1 and Bcl2 protein are detected in melanocytic lesions of the skin. We examined, for the first time, WT1 and Bcl2 expression in a variety of conjunctival melanocytic lesions to evaluate their diagnostic utility compared with other melanocytic markers.. Protein expression and localization of WT1 and Bcl2 were studied by means of immunolabeling and semiquantification in 123 conjunctival melanocytic lesions (71 benign nevi, 21 atypical nevi, 11 primary acquired melanosis, and 20 malignant melanomas). Ancillary immunohistochemical studies were performed with Bcl2, S100, HMB45, and Melan A antibodies.. WT1 showed a graded increase in expression in lesions with increasing atypia. Higher mean numbers of WT1-positive cells correlated with increasing atypia in melanocytes. In all cases, Bcl2 expression was positive and more robust than was S100, HMB45, or Melan A expression. WT1 and HMB45 frequently showed diffuse and strong staining in atypical nevi, primary acquired melanosis with atypia, and malignant melanomas compared with benign lesions.. Bcl2 is a highly sensitive immunohistochemical marker for melanocytic tumors of the conjunctiva; HMB45 and WT1 staining distinguishes benign from malignant lesions.. Our results show that HMB45 and WT1 immunolabeling is helpful in the evaluation of conjunctival melanocytic lesions. Accordingly, we recommend the development of an immunohistochemical panel to classify these lesions.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antigens, Neoplasm; Biomarkers, Tumor; Child; Child, Preschool; Conjunctival Diseases; Conjunctival Neoplasms; Dysplastic Nevus Syndrome; Female; Humans; Immunoenzyme Techniques; Male; MART-1 Antigen; Melanoma; Melanoma-Specific Antigens; Melanosis; Middle Aged; Neoplasm Proteins; Nevus, Pigmented; Proto-Oncogene Proteins c-bcl-2; S100 Proteins; WT1 Proteins; Young Adult

The authors investigated the expression of S100A1, S100A6, S100B, MelanA, and CEA in conjunctival naevi, primary acquired melanosis (PAM), conjunctival melanoma, and uveal melanoma in order to assess their potential usefulness in the pathological differential diagnosis of these entities.. Paraffin embedded sections of 18 conjunctival naevi, 14 PAM, 16 conjunctival melanomas, and 20 uveal melanomas were immunostained for S100A1, S100A6, S100B, MelanA, and CEA, and expression was scored semiquantitatively.. Expression of S100A1 differed significantly between conjunctival naevi and conjunctival melanoma, with percentages of positive cells of 30.6% and 71.4%, respectively. Conjunctival melanomas had high average scores for S100A1 and S100B (71.4%, 62.9%, respectively), while uveal melanomas also had high S100A1 but low S100B scores (88.5%, 18.5%, respectively). MelanA was highly variable; naevi and uveal melanoma had higher average scores than conjunctival melanoma. CEA was hardly detectable in all four groups.. S100A1 seems to be a possible candidate to differentiate conjunctival naevi from conjunctival melanoma. S100B seems to differentiate between uveal melanoma and conjunctival melanoma. However, the study size was small and therefore the data have to be confirmed by others.

Topics: Antigens, Neoplasm; Biomarkers; Carcinoembryonic Antigen; Cell Cycle Proteins; Conjunctival Diseases; Conjunctival Neoplasms; Diagnosis, Differential; Humans; Immunohistochemistry; MART-1 Antigen; Melanoma; Melanosis; Neoplasm Proteins; Nerve Growth Factors; Nevus; S100 Calcium Binding Protein A6; S100 Calcium Binding Protein beta Subunit; S100 Proteins; Uveal Neoplasms