Evidence behind the use of molecular tests in melanocytic lesions and practice patterns of these tests by dermatopathologists.

BACKGROUND: The gold standard for the diagnosis of melanocytic lesions is histologic examination. However, as histologic examination can have its limitations, there are many clinical scenarios in which additional testing may be appropriate in an attempt to render a definitive diagnosis. METHODS: A literature review for three ancillary tests-comparative genomic hybridization (CGH)/single-nucleotide polymorphism (SNP) array, fluorescence in situ hybridization (FISH), and gene expression profiling by quantitative reverse transcription polymerase chain reaction (qRT-PCR)-was compiled and current use patterns were tabulated. Survey of the practice patterns of these tests by dermatopathologists was also accessed in the attendees of the American Society of Dermatopathology Annual Meeting (Chicago, 2016). RESULTS: Here we summarize the use of these molecular tests in melanocytic lesions. We found that 54.4% of the respondents surveyed utilize (or expect consultants to utilize) molecular testing of melanocytic lesions in their practice when appropriate. CONCLUSIONS: CGH/SNP arrays, FISH testing, and qRT-PCR applied to melanocytic lesions have allowed for more accurate classification. Just over half of those surveyed use molecular testing for melanocytic lesion with the majority sending their cases out for completion of the molecular test.

Keratocystic odontogenic tumor associated with nevoid basal cell carcinoma syndrome: similar behavior to sporadic type?

OBJECTIVE: The objective of this study was to analyze the expression of proliferative markers and p53 in keratocystic odontogenic tumor (KCOT) sporadic type and KCOT associated with nevoid basal cell carcinoma syndrome (NBCCS). STUDY DESIGN AND SETTING: We performed a cross-sectional study. A total of 19 patients with KCOT were selected from the Oral Pathology Laboratory archives, Central University of Venezuela, from 1995 to 2005. SUBJECTS AND METHODS: Twelve cases corresponded to sporadic KCOT, and seven cases were associated with NBCCS. Immunohistochemical analysis for p53, proliferating cell nuclear antigen (PCNA), and Ki-67 was performed in all 19 cases. RESULTS: Of the seven cases associated with NBCCS, six (86%) were positive for PCNA. From the 12 sporadic cases, nine (75%) were positive for PCNA. Only one case of sporadic KCOT showed Ki-67 positivity. Five of 12 (42%) cases of sporadic KCOT were positive for p53, and only one (14%) case associated with NBCCS was positive for p53. CONCLUSION: On the basis of the analysis of the expression of PCNA, Ki-67, and p53, there appears to be no evidence to indicate higher aggressiveness in growth and infiltrative behavior in syndromic KCOT compared with the sporadic type. Therefore, surgical treatment may be approached in the same manner in KCOT sporadic and syndromic with the goal of minimizing recurrence.