Abstract
Decreased hydroxymethylated cytosine (5-hydroxymethycytosine, 5-hmC) is reported to correlate with melanocyte dysplasia. The purpose of this study was to assess the diagnostic utility of this observation. 5-hmC immunohistochemistry was performed on tissue microarrays containing 171-melanocytic lesions from two different institutions. An immunohistochemical staining score representing the percentage and intensity of nuclear staining was assigned. The performance characteristics of 5-hmC immunohistochemistry for discriminating between a nevus and melanoma were determined. Additional cases of melanoma arising in a nevus (n = 8), nodal nevi (n = 5) and melanoma micrometastases to a lymph node (n = 6) were also assessed. Pronounced 5-hmC loss was observed in melanomas when compared with nevi (mean ± standard deviation = 6.71 ± 11.78 and 55.19 ± 23.66, respectively, p < 0.0001). While the mean immunohistochemical staining score values for melanocytic nevi and melanoma were distinct, there was considerable variability in immunohistochemical staining score within a single diagnostic category. The sensitivity and specificity of this assay for nevus vs. melanoma is 92.74 and 97.78%, respectively. Distinct biphasic staining patterns were observed in cases of melanoma arising in association with a nevus. Relative changes of 5-hmC expression within a single lesion may be more informative than absolute values when using 5-hmC as a diagnostic adjunct.
Original language | English (US) |
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Pages (from-to) | 807-814 |
Number of pages | 8 |
Journal | Journal of cutaneous pathology |
Volume | 42 |
Issue number | 11 |
DOIs | |
State | Published - Nov 1 2015 |
Keywords
- 5-hydroxymethylcytosine
- dermatopathology
- epigenetics
- melanoma
- nevus
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Histology
- Dermatology