Rare Skin Tumor Behaves Differently Than Melanoma
University of Michigan Health System researchers have published new data to help answer two dreaded questions: "Is it cancer?" and "What type of treatment should I have?"
Cancer is the primary concern when abnormal skin lesions are detected. Macroscopic and microscopic features of a lesion usually provide clues about whether it is benign or malignant. However, the distinction is not always clear-cut, and doctors are faced with the question of how to best treat such patients.
The quandary is especially pronounced in atypical spitzoid tumors (ASTs), a rare proliferation of pigmented skin cells. ASTs have many features of melanoma, a potentially deadly form of skin cancer. ASTs tend to appear in patients who are much younger than the age when skin cancer traditionally occurs, which makes determining whether the lesion is malignant or benign even more difficult.
The new research, led by the University of Michigan Multidisciplinary Melanoma Program and published in the journal Cancer, suggests that ASTs behave differently from other types of melanoma. This finding could eventually lead to fundamental changes in the way ASTs are treated.
"As patients with AST appear to do better than conventional melanoma after similar treatment, we are now able to provide some reassurance to concerned parents and loved ones about the implications of the diagnosis," says lead study author Mathew Ludgate, MBChB, FRACP, assistant professor in the U-M Multidisciplinary Melanoma Program.
Although ASTs are rare, the U-M Multidisciplinary Melanoma Program has considerable experience as a preeminent national referral center. ASTs are an increasing challenge for physicians, as the number of ASTs diagnosed throughout the country appears to be increasing for unknown reasons. The researchers focused on long-term outcomes of ASTs to formulate improved evidence-based treatment guidelines.
Doctors generally treat patients with AST similar to malignant melanoma by surgically removing the lesion and in many cases also with a sentinel lymph node biopsy. The sentinel lymph node biopsy involves the removal and evaluation of one or a few lymph nodes nearest the skin lesion to determine whether the skin lesion has spread to the lymph nodes.