Rare, Dangerous Skin Cancers – Traditionally, said Michael B. Morgan, M.D., dermatologists and dermatopathologists are taught that the clinical presentation of Merkel Cell Carcinoma (MCC) is nondescript. "But there are some distinctive features to consider. If we were to take a cohort of patients with MCC, about 50 of them would show a periocular location." Additional hallmarks include large size – at least 1 cm, on average at diagnosis. Dr. Morgan is professor of pathology, University of South Florida College of Medicine, and professor of dermatology, Michigan State University College of Medicine.
World-Class Actinic Keratosis (AK) Panel – Neil Bhatia, M.D., asked, "Is actinic keratosis the disease, or a symptom of a bigger disease – photodamage? Or more importantly, is it already a squamous cell carcinoma (SCC) in situ?" He embraces the concept of subclinical AK and field treatment. For every AK you can see, he said, many more are developing, and it's important to nip the risk of invasive SCC in the bud. Dr. Bhatia is a Long Beach, California-based dermatologist in private practice and an associate professor of dermatology at the Harbor UCLA Medical Center.
Dallas-based dermatologist and dermatopathologist Clay J. Cockerell, M.D., said that although he believes AKs should be biopsied and treated, it may not be feasible to treat every AK. "It's impossible to remove every single lesion. You're not going to be able to wipe out every last keratinocyte that has been damaged. You can try, but AK is going to come back." However, he added, "I'm not a big believer in regression of AKs. I believe it’s more inflammation that comes one day and goes the next. Nobody's ever biopsied" a supposedly regressed AK. Therefore, "I take a reasonable rather than literal approach – remove as many as you can, follow the patient and use topical therapy" where appropriate.
Among AK treatments, Brian Berman, M.D., Ph.D., highlighted painless photodynamic therapy. In a small study, one method using 15 minutes' incubation with aminolevulinic acid painlessly provided AK reductions comparable to those of much longer incubation periods. He is a voluntary professor of dermatology and cutaneous surgery, University of Miami.
Nauseating Nevi –Dr. Cockerell addressed several conundrums surrounding the worry-inducing dysplastic nevus. It's not a premalignant lesion, he said. "It's a benign lesion that has characteristic clinical and histological features that may – sometimes but not always – be markers for melanoma." With little agreement on grading systems, he added, "I'd rather just use 2 grades – high-grade and low-grade."
Cutaneous Paraneoplastic Syndromes – With papulosquamous, interface and other disorders in this category, said Seemal Desai, M.D., "The most important factor is, which comes first – the cancer or the skin condition?" For example, he said, Bazex's Syndrome gives dermatologists and dermatopathologists an opportunity to save lives, as new-onset psoriasis symptoms in elderly patients precede development of SCC of the aerodigestive tract by about a year. He is clinical assistant professor of dermatology, University of Texas Southwestern, Dallas.
Perplexing Pigmentary Disorders – "We as dermatologists fall in the trap of thinking that everything dark on the face is either post inflammatory hyperpigmentation (PIH) or melasma," said Dr. Desai. These are the most common causes of local hyperpigmentation. However, he said, performing a full-body skin exam might provoke consideration of other causes, from drug reactions to vitamin deficiencies and melanocytic lesions.
When examining a biopsy, said Dipti Anand, M.D., "We are often asked to determine whether it's PIH or melasma. This can be difficult, but certain features can be helpful." With melasma, for example, "You can distinctly see epidermal hypermelanosis, and this pigment often forms a cap around the nucleus of the keratinocyte." She is an Atlanta, GA -based dermatopathologist at SkinPath Solutions.
Pediatric Potpourri – Anna Bruckner, M.D., presented an algorithm for evaluating blisters and erosions in newborns. After infections, she said, consider less likely, often genetic causes such as epidermolysis bullosa. Its diagnosis is best confirmed by immunofluorescence microscopy, she added, though genetic testing will assume a larger role. Immunofluorescence microscopy is relatively quick, inexpensive and accurate for diagnosing certain EB subtypes. "The kicker is, you must use a lab that uses very specific antibodies to the proteins expressed in the basement membrane zone." She is associate professor of dermatology and pathology, University of Colorado.