A new study suggests that mass spectrometry imaging, a technique that allows the identification of several molecules, such as metabolites, peptides and proteins, DNA segments, and lipids from tissue samples, can provide a more accurate diagnosis of melanoma than standard procedures.
Currently, diagnosing melanoma is traditionally done by examining skin biopsies with a microscope. However, results from this method are sometimes inconclusive. Researchers are now hopeful that mass spectrometry can give physicians more accurate, reliable results that in turn will improve patient outcomes.
The study, “Imaging mass spectrometry assists in the classification of diagnostically challenging atypical Spitzoid neoplasms,” was conducted by Dr. Rossitza Lazova, MD, from Yale University along with researchers from other research institutes, and published in the Journal of the American Academy of Dermatology.
“In this study, we sought to determine whether imaging mass spectrometry (IMS) could assist in the diagnosis and risk stratification of [atypical moles] by performing IMS in a large series of cases with known clinical follow-up, by comparing in each case the diagnosis rendered by IMS with the histopathological diagnosis and correlating the diagnoses with clinical outcome,” the authors wrote in their report.
A histopathological diagnosis is one that is made by microscopically examining tissue samples, in this case corresponding to the skin biopsies performed in traditional diagnostic procedures for melanoma.
To make this comparison, researchers conducted a retrospective collaborative study involving centers from 11 countries and 11 U.S. institutions, and analyzed skin samples of atypical moles from approximately 100 participants by IMS.
In this analysis, they compared individual proteins in the biopsies to a profile of five proteins that had been previously identified as being expressed in different amounts between benign moles and melanoma, developing a specific signature to distinguish between the two. The researchers then compared the results obtained with IMS with those obtained by the standard microscopic analysis of skin samples. The results showed that IMS provided a more accurate identification of benign moles or melanoma in almost all cases.
This finding suggests that some molecular changes that are invisible to standard histopathology can be detected by IMS, making the technology useful in the accurate diagnosis of melanoma.
“Instead of pathologists being dependent solely upon the physical appearance of the cells, they now have the additional advantage of molecular information regarding the protein makeup [of cells] provided by mass spec imaging,” said Lazova in a news release. “This test integrates anatomic pathology and analytical chemistry in a very useful and meaningful way.”