Article
Melanocyte localization and distribution in human cholesteatoma
Search Medline for
Authors
Published: | April 24, 2007 |
---|
Outline
Text
Introduction: Melanocytes in skin are derivates of the neural crest and colonize the epidermis in the first trimester of gestation. During embryogenesis, the pharyngeal pounches generate the mucosa of the middle ear, the nasopharynx, and the mounth. The aim of our study was to evaluate the prevalence and role of melanocytes in human cholesteatoma and normal meatal skin in Caucasian adults.
Material and methods: Human cholesteatoma (n=18) and normal meatal skin samples (n=10) were investigated immunohistochemically with anti-HMB-45 and MART-1 antibodies. Localization and distribution of melanocytes were assessed in the epidermis and cholesteatoma using the automatic analyzing system (DP SOFT version 3.2, New York, USA).
Results: Regular skin exhibited melanocytes within the epidermis and accounting for 10% of the total cell number. They occurred partly as membrane-bound clusters. Cholesteatoma matrix melanocytes were observed in the basal layer of exhibiting an oval or round morphology. Decreased numbers of melanocytes in the basal layer correlated with keratinization in cholesteatoma samples. Melanocytes revealed monomorphous nuclei, abundant cytoplasm containing particles of melanin. Accounting for 2-6% of the total cell number within the squamous epithelium, melanocytes density was significantly lower in cholesteatoma tissue than in skin.
Conclusion: Melanocytes distribution pattern was slightly different compared the epithelia of skin and cholesteatoma. The presence of melanocytes in cholesteatoma may be due to an ingrowth consequently controlled by keratinocyte-derived signals. In terms the pathogenesis of cholesteatoma matrix neither squamous metaplasia nor melanocyte metaplasia can be excluded by our data.