Sampling of melanocytic nevi for research purposes: A prospective, pilot study to determine effect on diagnosis
Background
Research on melanocytic nevi predominantly utilizes formalin-fixed, paraffin-embedded tissue, largely limiting research to morphologic and immunohistochemical observations. Withholding portions of fresh nevus tissue for molecular studies could result in the loss of important diagnostic material.
Objective
This study prospectively evaluated melanocytic nevi for histologic homogeneity to determine if using a portion for research would have affected diagnosis.
Methods
Thirty-three subjects were enrolled in a prospective study in which pigmented lesions were chosen for biopsy on a clinical basis. Lesions were sectioned and each piece submitted in a separate block (mean, 2.7; range 2-5 blocks per lesion). Slides from nevi were examined in two phases. In phase I, sections of nevi were randomized and a diagnosis was rendered for each section of nevus. In phase II, the dermatopathologist reviewed all slides for each nevus as a case, similar to the original interpretation of the lesion provided to the clinician. Diagnoses from phases I and II were compared with the original diagnosis.
Results
Case material included 51 melanocytic lesions from 31 subjects. The phase I diagnosis matched the original diagnosis for 99 of 121 slides that showed a melanocytic lesion (82%). The phase II diagnosis matched the original diagnosis for 45 of 51 specimens (88%).
Limitations
The study was limited by: a small number of specimens; the clinician could have chosen clinically homogeneous nevi for biopsy; effect of interobserver and intraobserver variability on diagnosis.
Conclusions
For the majority of melanocytic nevi in this study, the diagnostic information present in one section of a melanocytic nevus could be extrapolated to the remainder of the specimen without adverse consequences from a diagnostic or therapeutic perspective.
aThe Melanoma Program, Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah
bDepartment of Dermatology, University of Utah, Salt Lake City, Utah
cDepartment of Oncological Sciences, University of Utah, Salt Lake City, Utah
dDepartment of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas
Reprint requests: Scott R. Florell, MD, Department of Dermatology, University of Utah Health Sciences Center, 4B454 SOM, Salt Lake City, UT 84132.
Supported by grants from The Skin Cancer Foundation (to S. R. F.), the Dermatology Foundation Leaders Society Dermatologist Investigator Research Fellowship and Clinical Career Development Award (to S. R. F.); National Institutes of Health grants K23 RR17525-01 (to S. R. F.) and R01 AR50102 (to D. G.), Doris Duke Charitable Foundation (to S. A. L.), Fellowship-To-Faculty Transition Award from the University of Utah funded in part by the Howard Hughes Medical Institute (to S. A. L.), The Huntsman Cancer Foundation (to S. A. L., D. G.), the Tom C. Mathews Jr. Familial Melanoma Research Endowment, Huntsman General Clinical Research Center Public Health Service grant (MO1 RR00064), National Cancer Institute (NCI) Cancer Center Support grants 5P30CA420-14, and the Utah Cancer Registry, funded by Contract # N01-PC-35141 from the NCI with additional support from the Utah Department of Health and the University of Utah.
ABSTRACT