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Meet The Faculty

The Department of Dermatology at Mayo Clinic's campus in Rochester, Minnesota, offers a full range of dermatologic care for both common and rare problems of skin, hair, nails, and mucous membranes. The department has a robust faculty practicing in all areas of dermatology, including: clinical, surgical, and laboratory.

More than 18,000 surgical procedures are performed annually in the surgical suites in the Gonda Building, 16th Floor, which includes 16 procedure rooms and a histology lab. The dermatopathology practice interprets more than 30,000 specimens annually from our practice, and there is an immunodermatology lab with a large volume of referred specimens sent through Mayo's reference laboratory.

Jerry Brewer, M.D., M.S.From the program director

Thank you for your interest in our program and for taking the time to learn about Mayo Clinic’s fellowship in Micrographic Surgery and Dermatologic Oncology in Rochester, Minnesota.

As I consider my career thus far, the word that comes to mind is gratitude. As dermatologic surgeons, we have the ability to care for those with skin cancer like no other can. I see the level of care delivered in the area of micrographic surgery and dermatologic oncology raised to new heights, year after year. As Mohs surgeons, we offer hope, cure, and compassion with exceptional function and cosmesis. I am so grateful I have the opportunity to participate in such an awe-inspiring career, and I am equally grateful you have an interest in this great profession. 

In our program, we offer a robust experience with incredible exposure to all aspects of micrographic surgery and dermatologic oncology. Our core faculty members are gifted surgeons who are committed to the development of fellows and are dedicated in their ability to deliver care, collaborate, and teach.  We pride ourselves in our pursuit of excellence, with the over-arching value of Mayo Clinic “the needs of the patient come first.” 

As a fellow in our program, you will have opportunities to learn from many different fine-tuned surgical styles. You will also spend time in the histology lab cutting tissue, participate in cadaver lab sessions, learn pearls from accomplished Mohs surgeons regarding successful micrographic surgical practices, and find opportunities in our leadership curriculum to develop skills in critical areas of life including conflict resolution, giving and receiving feedback, understanding implicit bias, communication styles, wellness, burnout, emotional intelligence, and presentation skills. 

I strive hard to foster a culture of psychological safety and a growth mind set, with the notion that mistakes happen, but what is most important is how we learn from those mistakes as part of our journey in pursuit of excellence. I am an advocate of ambition mixed with kindness, and am a fan of the higher-level attribute gratitude.

Our incredible patients come from various walks of life, some living in this very community and others traveling across the world to get here. 

It is truly an honor to serve as fellowship program director. I am excited for what the future brings, for the strides this great profession will make in my lifetime and beyond, and for the possibility of being a part of your learning and development. 

Thank you again for your interest in this incredible career and for taking the time to learn about our program. I wish you all the best!

Jerry Brewer, M.D., M.S.
Micrographic Surgery and Dermatologic Oncology Fellowship Program Director


Mayo Clinic's faculty members are committed to teaching and facilitating the advancement of medical knowledge, in addition to caring for patients in their clinical practices. Many of our faculty have published and lectured extensively and are well-regarded in their fields. You have direct access to these individuals throughout the Micrographic Surgery and Dermatologic Oncology Fellowship.

Christian Baum, M.D.

Christian Baum, M.D.

Dr. Baum was born and raised in Iowa. He received his M.D. from the University of Iowa in 2005. He completed his dermatology residency and a fellowship in micrographic surgery and cutaneous oncology at the University of Iowa Hospitals and Clinics.

Dr. Baum has been on staff at Mayo Clinic since 2010. He cares deeply about treating patients with skin cancer and has a particular interest in the most vulnerable and high-risk populations. His primary objective is to treat patients with the same diligence and compassion that we would want for his family. He thoroughly enjoys teaching and learning from residents and fellows, and he treasures the long-term relationships that have developed with patients and colleagues.

Dr. Baum and his wife are blessed with three children.

Jerry Brewer, M.D., M.S.

Jerry Brewer, M.D., M.S.

Dr. Jerry Brewer is the program director of the Micrographic Surgery and Dermatologic Oncology Fellowship at Mayo Clinic in Rochester, Minnesota.

He grew up in the small town of Vernal, Utah, and knew he was going to be a physician at the age of five. He attended medical school at Wayne State University in Detroit prior to completing internship at Yale, and then dermatology residency and micrographic surgery and dermatologic oncology fellowship both at Mayo Clinic. He feels fortunate to have had the opportunity to join the faculty of Mayo Clinic after completing training, and although he misses the mountains, has grown to love Minnesota.

Dr. Brewer has developed a passion for mentoring and leadership development. His clinical and academic interests include melanoma epidemiology, high risk skin cancer in immunosuppressed patients, Merkel cell carcinoma, hyperhidrosis, and vein surgery. 

Outside of work, you might run into Dr. Brewer on one of the trails around Rochester taking a jog or going on a bike ride with his family. He enjoys learning new skills and is currently learning French and Italian, as well as taking up the guitar. His favorite restaurant in town is Mango Thai!

Addison Demer, M.D.

Addison Demer, M.D. (he/him)

Dr. Demer is one of our Mohs surgeons; he serves as the associate program director for the MSDO Fellowship and the chair of Mayo Clinic’s Cutaneous Oncology eTumor Board. He grew up in the Twin Cities, where he trained at the University of Minnesota. He has research and clinical interests in special-site cutaneous melanoma, high-risk non-melanoma skin cancer, digital imaging/AI in dermatology, and cutaneous reconstruction. His favorite part of life at Mayo is working closely with and teaching our tremendous trainees.

Outside of work, Dr. Demer can often be found out on the Whitewater State Park hiking trails with his wife and three kids, traveling, “ripping it up” on his Onewheel or fat tire mountain bike, snowboarding, camping, boating at the cabin, or doing any number of active hobbies. When not on-the-go, you may find him with a burrito or ice cream cone in hand watching Netflix.

Molly Lohman, M.D.

Molly Lohman, M.D.

Dr. Lohman is one of our Mohs surgeons and serves as the director of Dermatology Surgery Resident Education. Originally from northeast Ohio, she worked in agriculture and food manufacturing prior to medical school. She has enjoyed traveling for training — she completed medical school at Northwestern University in Chicago, attended residency at the University of California, San Francisco, and completed her fellowship at the Mayo Clinic in Rochester. She has research and clinical interests in quality improvement and resident education.

Outside of work, Dr. Lohman can be found outdoors with her family. She loves gardening, hiking, and camping. Her favorite parts of Minnesota are the flyfishing and cross-country ski trails.

Clark Otley, M.D.

Clark Otley, M.D. (he/him)

Dr. Otley is one of our Mohs surgeons. He grew up in New Jersey, majored in religion at Williams College, and then attended Duke University for medical school, where he got hooked on dermatology. After doing internship at Brigham and Women’s Hospital, he completed the dermatology residency at the Harvard Combined program. Thinking he was heading to Mayo Clinic only for a one-year fellowship in cutaneous oncology and Mohs surgery, he was hooked and has spent his entire career in Mayo Clinic’s Department of Dermatology. He has previously served as chair of the department of dermatology and as the president of the American College of Mohs Surgery. He has research and clinical interests in the care of solid organ transplant patients, high-risk non-melanoma skin cancer, and reconstruction. He very much enjoys working with our residents and fellows. When he’s not focused on dermatology, he has served as medical director of Mayo Department of Business Development, is Chief Medical Officer of Mayo Clinic Platform, and president of Destination Medical Center Economic Development Agency.

Outside of work, Dr. Otley enjoys spending as much time as possible outdoors, mountain and gravel biking, cross-country and downhill skiing, camping, and hiking with his wife Jill. They get together with their adult kids and their fiance's and spouses as often as possible. 

Randall Roenigk, M.D.

Randall Roenigk, M.D.

Dr. Roenigk graduated from Northwestern University Medical School in 1981, completed an internship at St. Paul Ramsey County (now Regions) Hospital followed by dermatology residency at the University of Minnesota before completing his fellowship in dermatologic surgery (Mohs) at the Cleveland Clinic. In 1986, he joined the staff at Mayo Clinic to start the surgical practice in the Department of Dermatology, where in 1990 he also started the surgical fellowship program, training 43 fellows.  In 1998, he was appointed chair of the Department of Dermatology at Mayo Clinic in Phoenix, Arizona, and in 2000, chair of the Department of Dermatology at Mayo Clinic in Rochester, Minnesota. In 2007, he was honored by Mayo Clinic as the Robert H. Kieckhefer Professor in Dermatology. 

Dr. Roenigk served as a member and chair of the Residency Review Committee for Dermatology of ACGME from 1994-2000 and 2002-2010. He was elected a director of the American Board of Dermatology in 2000 and president in 2009. In 2013, he was appointed as the assistant executive director of ABD and in 2021 the executive director of ABD. He has received several lifetime achievement awards for his work to gain accreditation and certification in our surgical subspecialty including, the President’s Award in 2003 by the American Society for Dermatologic Surgery, a Distinguished Service award in 2009 by the American Board of Dermatology, and he was honored by the American College of Mohs Surgery in 2011 with the Fredrick E Mohs, M.D. Award for Lifetime Achievement. He has authored over 220 peer-reviewed articles and two books, including three editions of his textbook Dermatologic Surgery: Principles and Practice co-edited with his father, Dr. Henry Roenigk.

In addition to serving as the Executive Director of the American Board of Dermatology, Dr. Roenigk maintains a surgical practice at Mayo Clinic that includes teaching residents and fellows.

He has been married to Julie for 41 years and shares two children and a grandchild.   

Nahid Vidal, M.D.

Nahid Vidal, M.D.

(pronounced Nuh-HEED, Vidal pronounced like Vital signs)  

Dr. Vidal is a board-certified Mohs micrographic surgeon and cutaneous oncologist at Mayo Clinic. She currently serves as the chair of the Division of Dermatologic Surgery. She grew up in California, where she spent considerable time on art, math/physics, and athletics. She attended Stanford University for her undergraduate degree, University of California Davis for her medical degree, and University of Iowa Hospitals & Clinics for dermatology residency. She first came to Mayo Clinic for fellowship in micrographic surgery and dermatologic oncology, and after completing fellowship served as director of dermatologic surgery at Dartmouth-Hitchcock in New Hampshire. Dr. Vidal then returned to Mayo Clinic as faculty and has enjoyed being involved in curriculum improvements, residency admissions, and teaching fellows and residents. She loves the innovative and collaborative environment at Mayo Clinic, and the opportunities to grow and be challenged. Her academic interests include high-risk and rare cutaneous malignancies (such as Extramammary Paget’s Disease), complex facial reconstruction, and artificial intelligence/machine-learning.

Outside of medicine, Dr. Vidal enjoys time with family, playing basketball, watching Marvel, stand-up comedy, cooking and eating (more the latter), hosting, and learning new skills (never too old to learn).

Advisers and mentors

You are assigned a faculty adviser who can provide comprehensive educational advice and personal support. Your adviser also serves as a contact point, introducing you and your family to Mayo Clinic and the community of Rochester, Minnesota.

Visiting professors

Many prominent professors visit Mayo Clinic each year. They present their work during lectures and participate in hospital rounds. You may encounter visiting professors in the area of dermatologic surgery throughout your fellowship, and you are encouraged to take full advantage of these opportunities.