Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Melanoma may be over-diagnosed

18.07.2006
Researchers note first-ever criteria for distinguishing sun damage from early melanoma, providing guidelines to lessen removal of healthy tissue

A Mayo Clinic physician and colleagues have defined the normal number of melanocytes that are present in Caucasians' sun-exposed skin. Until now, there has not been a criterion to distinguish sun damage from early (in situ) melanoma. Results of the study, which shed light on this undefined area in skin cancer, are available in the July issue of Archives of Dermatology.

"There are many uncertainties in medicine. In many instances these uncertainties lead to overly aggressive treatments," says Ali Hendi, M.D., Mayo Clinic dermatologic surgeon and lead investigator of the study. "We didn't have an accurate way to distinguish cancer from over-exposed but normal skin, and this study was designed to find the missing link."

There are two basic types of skin cancer, non-melanoma, which includes basal cell and squamous cell cancers, and melanoma. Melanoma is the deadliest, reports the American Cancer Society, accounting for only 4 percent of diagnosed skin cancers, but nearly all of the deaths. It originates in melanocytes, the cells that produce melanin, which colors skin, hair and eyes.

Dr. Hendi's team thought that pathologists and Mohs surgeons may err on the side of over-diagnosing melanoma in sun-damaged skin, leading to additional and unnecessary surgery, complications or deformity. Mohs surgery, named for Frederic E. Mohs, M.D., who developed the technique, allows incremental removal of skin cancers, reducing removal of tissue to just the diseased areas. Mohs surgeons remove a thin section of the tumor, review its pathology under a high-powered microscope and are able to stop tissue removal as soon as the edge of the diseased tissue is reached. Because of this assumption of overly cautious surgery, the researchers decided to develop criteria by which cell changes that can indicate noncancerous sun damage can be distinguished from those which indicate melanoma.

In the study, disease-free tissues samples were obtained from 132 randomly selected Caucasian patients undergoing Mohs surgery for non-melanoma skin cancers of the face and neck. The samples were cut from the edges of the excised area, and consisted of normal, noncancerous skin. They found that in normal sun-exposed skin, the number of melanocytes in a 0.5 millimeter (mm) diameter was 15.6 (as opposed to undamaged skin that might have five to seven). Adjacent melanocytes, another indicator used by pathologists to diagnose early melanoma, were present in varying degrees in all but 11 percent of the samples. Finally, melanocytes were found to descend along the hair follicles, a finding previously attributed only to melanoma in sun-damaged skin. The researchers say these findings are significant because many surgeons remove tissue until they reach undamaged cells with "normal" melanocyte distribution.

Dr. Hendi predicts the study's findings will be valuable to doctors who diagnose and treat melanoma. "To be able to look in the microscope and have a measurement by which to determine successful removal of melanoma in situ is something we've hoped for quite a while," he says. "In many cases, surgeons can stop removing tissue much sooner, which will result in less trauma to the skin." Dr. Hendi's team recommends doctors use the study's findings as their new baseline for melanoma diagnosis and tissue removal.

Christine Leon | EurekAlert!
Further information:
http://www.mayo.edu

More articles from Health and Medicine:

nachricht Another reason to exercise: Burning bone fat -- a key to better bone health
19.05.2017 | University of North Carolina Health Care

nachricht Disrupted fat breakdown in the brain makes mice dumb
19.05.2017 | Rheinische Friedrich-Wilhelms-Universität Bonn

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

Im Focus: Hydrogen Bonds Directly Detected for the First Time

For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.

Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

Media accreditation opens for historic year at European Health Forum Gastein

16.05.2017 | Event News

 
Latest News

New approach to revolutionize the production of molecular hydrogen

22.05.2017 | Materials Sciences

Scientists enlist engineered protein to battle the MERS virus

22.05.2017 | Life Sciences

Experts explain origins of topographic relief on Earth, Mars and Titan

22.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>