Meet our team

Donn LaTour, M.D., Ph.D. – PHYSICIAN

Dr. Donn LaTour received his medical degree from Loma Linda University of Medicine and his PhD in Biochemistry/ Molecular Biology. He completed his dermatology residency, as well as a one-year advanced Mohs Skin Cancer Surgery Fellowship at the Loma Linda University Medical Center in California.

Dr. LaTour’s Mohs Skin Cancer Surgery Fellowship provided him with in depth expertise in the management of skin cancer. Mohs surgery is a very specialized way to remove skin cancers preserving as much skin tissue as possible, while providing a high cure rate for the skin cancer.

Dr. LaTour returned to his home state of Michigan, to begin his practice in 1997. Since that time, he has expanded his practice with offices in Jackson, Kalamazoo, Battle Creek, Sturgis and Angola. Dr. Donn LaTour is certified by the American Board of Dermatology and is a member of the American College of Mohs Surgery.

Esther M. LaTour, M.D. – PHYSICIAN

Dr. Esther LaTour earned her undergraduate degree biochemistry at Loma Linda University in California. She received her medical degree from Loma Linda University School of Medicine. Dr. Esther LaTour then completed a masters program in nutrition, her residencies in Family Practice and in Preventive Medicine at Loma Linda University.

Dr. Esther LaTour is certified by the American Board of Family Practice. She and her husband, Dr. Donn LaTour, and their family moved to Michigan in 1997. Dr. Esther LaTour has worked exclusively providing dermatology services since the opening of the first Dermatology & Skin Surgery Center office.

Walter Korytowsky, M.D. – PHYSICIAN

Dr. Walter Korytowsky received his medical degree from the University of Michigan. He completed his dermatology residency at the University of Illinois at Chicago. He is board certified by the American Board of Dermatology.

Caleb Lee, D.O. - PHYSICIAN

Dr. Caleb Lee received a Master of Science degree in physical therapy from Andrew University in Berrien Springs, Michigan. Dr Lee furthered his medical education by obtaining his medical degree at Kirkville College of Osteopathic Medicine in Missouri. He returned to Michigan to complete his residency at Ingham Regional Medical Center in Lansing. Dr. Lee is Board Certified in Internal Medicine.

After practicing as a licensed physical therapists for several years, Dr. Lee decided to expand his scope of practice from providing therapy to the role of physician diagnosing and providing preventative care. In 2010 after completing his Internal Medicine medical training, Dr. Lee decided to focus on dermatology and joined Dermatology & Skin Surgery Center.

Amber Corneillie, PA-C – CERTIFIED PHYSICIAN ASSISTANT

Amber received her Bachelor of Science in Exercise and Health Science from Alma College, in Michigan. She continued her education with Emergency Medical Technician training at Lansing Community College and is a licensed EMT. Amber completed her Master of Science Degree in Physician Assistant Studies at Central Michigan University, located in Mount Pleasant, Michigan. Amber is certified by the National Commission on Certification for Physician Assistants. She is an active member of the American Academy and the Michigan Academy of Physician Assistants, as well as the Society of Dermatology Physician Assistants.

Following her academic training, Amber worked in general surgery for three years, giving her clinical knowledge and a strong foundation that built her dermatology skills. She is interested in all aspects of dermatology. Amber joined the Dermatology & Skin Surgery Center, with office locations in Battle Creek, Jackson, and Kalamazoo in 2007.

Thomas D. Till, PA-C – CERTIFIED PHYSICIAN ASSISTANT

Tom earned his undergraduate degree in microbiology and medical technology from the University of Washington in Seattle, Washington. He completed his Bachelor of Science degree in medicine at the Physician Assistant Program of Western Michigan University in 1994.

Tom joined the Dermatology & Skin Surgery Center 2006 . Prior to joining Dermatology & Skin Surgery Center, Tom provided competent and compassionate general medical care, including dermatology for thirteen years. He has extensive experience providing care to both adults and pediatric patients. Tom is certified by the American Academy of Physician Assistants and is a Diplomate of the Society of Dermatology Physician Assistants. Tom has limited his practice to dermatology for over 9 years.

Jared P. Wilson, M.S., PA-C. – CERTIFIED PHYSICIAN ASSISTANT

Jared's medical career began in the U.S. Navy in 1993 with EMT training and as leading Petty Officer in an emergency room. In 1995, he attended the U.S. Navy/Marine Corps Field Service School, and then provided medical care in a primary setting at the Marine Corps Air Station in Cherry Point, North Carolina. After the service, Jared earned an associate degree in Applied Science at Ferris State, Big Rapids, Michigan.

In 2000, he earned his undergraduate degree in Biology also from Ferris State University. Jared completed his Master of Science in Medicine at the Physician Assistant Program of Western Michigan University, Kalamazoo, Michigan in 2003. Jared has been a Physician Assistant since 2003, functioning as a surgical assist for vascular and thoracic cases, and providing pre and post-operative treatment. In 2005, Jared joined Dermatology & Skin Surgery Center with office locations in Battle Creek, Jackson and Kalamazoo, Michigan. Jared has been providing dermatology care for over 10 years. Jared is a Diplomate of The Society of Dermatology Physician Assistants.

Stephanie Mason, PA-C – CERTIFIED PHYSICIAN ASSISTANT

Steve Heckel, PA-C – CERTIFIED PHYSICIAN ASSISTANT

Steve earned his bachelor degrees in health science & occupational safety & health at Grand Valley State University, Allendale, Michigan. He obtained his master degree in Physician Assistant at Grand Valley State University.

Steve worked as a Physician Assistant for several years prior to joining Dermatology & Skin Surgery Center in 2012 and limiting practice to dermatology. Steve’s combined over 10 years experience as a Physician Assistant includes emergency medicine, occupational medicine and orthopedic medicine, where he assisted in surgery. His training and clinical knowledge has provided a strong foundation for the specialty of dermatology. He is Certified by the National Commission on Certification of Physician Assistants. 

Courtney Converse, PA-C – CERTIFIED PHYSICIAN ASSISTANT

In 2002, Courtney received her Bachelor of Science in Exercise & Health Science from Alma College, Alma Michigan. In 2004, she received her Master of Science from Central Michigan University in Mount Pleasant, Michigan. Courtney was certified through the National Commission on Certification of Physician Assistants.

Prior to joining Dermatology & Skin Surgery Center, Courtney worked in family practice, general surgery and Colon & Rectal Surgery. She has over 10 years of experience as a Physician Assistant including family medicine, serving a diverse patient population, and surgical skills. Courtney joined the Dermatology & Skin Surgery Center in 2015, and has limited her practice to dermatology.

Maxine M. Weller, NP-C - CERTIFIED NURSE PRACTITIONER

Maxine (Max) received her associate degree in Nursing at Jackson Community College. She earned her undergraduate degree in Health Science at Spring Arbor University. Max completed her Master of Science in Nursing at Andrews University, Berrien Springs, Michigan. She joined the Dermatology & Skin Surgery Center in 2000. Prior to joining Dermatology & Skin Surgery Center, Max worked as a Nurse Practitioner in family and emergency medicine. As a Registered Nurse she worked at Foote Hospital in geriatric nursing and case management. Max has worked in both primary and geriatric care settings providing care for patients of all ages.

Max is certified as Nurse Practitioner and as a Registered Nurse by the State of Michigan. The American Nurse Credentialing Center has certified her for Case Management, Geriatric Nursing and as an Adult Nurse Practitioner. Max has over 15 years’ experience providing dermatology care to patients of all ages.

Diana Parks, M.S., FNP-BC – CERTIFIED NURSE PRACTITIONER

Diana completed her Registered Nurse Diploma at Albany Medical Center Hospital School of Nursing, Albany New York. She received her Bachelor of Arts degree at the University of Maryland University College in Heidelberg, Germany while she lived oversees. Diana received her Master of Science in Nursing as a Family Nurse Practitioner from the Medical College of Virginia, Richmond Virginia. Prior to joining Dermatology & Skin Surgery Center, she worked in several primary care settings providing healthcare for patients of all ages.

In 2010 Diana joined Dermatology & Skin Surgery Center working mostly in the Jackson office. She has over 20 years in practice as a certified Nurse Practitioner. Diana is a member of Sigma Theta Tau the International Honor Society of Nursing, the National Academy of Dermatologic Nurse Practitioners, the Dermatology Nurses Association & the Michigan Council of Nurse Practitioners.

In 2000 Gerri received her Bachelor of Science in Nursing from Bowling Green State University graduating with a perfect 4.0. Gerri received her Master of Science in Nursing with a Family Nurse Practitioner concentration from the Medical College of Ohio/University of Toledo Medical College in Toledo, Ohio in 2002. She graduated first in her class & received the Deans Award. She also became Certified Nurse Practitioner in 2002.

Prior to joining Dermatology & Skin Surgery Center, Gerri worked in Montpelier & Bryan, Ohio for over 11 years providing dermatologic care to patients of all ages. Gerri joined the Dermatology & Skin Surgery Center in 2014.

Katrina Hadcock, FNP-BC – CERTIFIED NURSE PRACTITIONER

Katrina became a Board Certified Family Nurse Practitioner in 2013. She received her Master of Science in Nursing with a Family Nurse Practitioner concentration from Saginaw Valley State University, in Michigan. Katrina began her medical career as a Licensed Practical Nurse, she became a Registered Nurse and then received her Bachelor of Science in Nursing (BSN) from the University of Michigan-Flint in 2010 while working in a Michigan hospital in general medical, vascular and cardiac units. Katrina joined the Dermatology & Skin Surgery Center in 2013, limiting her practice to dermatology.

In 2012 Katrina was named the McLaren Greater Lansing Nurse of the Year. She received the Outstanding Merit & Accomplishment Award from U of M- Flint & was a member of the Honor Society at Saginaw Valley State University

Sarah Salvaggio, MSN, FNP - CERTIFIED NURSE PRACTITIONER

Sarah attended the University of Massachusetts Dartmouth where she received a Bachelor of Science in Nursing in 2010. She began her medical career working as an ICU Nurse in a level II trauma center, where she became certified in trauma medicine.

In 2014, Sarah received a Master of Science in Nursing as a Family Nurse Practitioner from the Massachusetts College of Pharmacy and Health Sciences University.



Relocating to Michigan with her husband in 2015, Sarah provided care with a focus on women’s health. In 2016, Sarah joined the Dermatology and Skin Surgery Center, working in both the Battle Creek and Jackson offices. Sarah works under the supervision of Dr. Donn LaTour and the other physicians of the Dermatology and Skin Surgery Center. She has daily communication and contact with the physicians.

Jessica Farhat, MSN, NP-C- CERTIFIED NURSE PRATITIONER

Jessica is a board certified Nurse Practitioner. She completed her graduate program at Michigan State University, earning a Masters of Science in Nursing as a Family Nurse Practitioner. Jessica was the recipient of the Outstanding Student Award for class of 2016 at Michigan State University. During her time at MSU her advocacy for Nurse Practitioners grew and she began lobbying at local levels. She was awarded the MSU’s Health Policy Fellowship and she utilized that opportunity to lobby at Capital Hill. As Past President, she co-founded Michigan Council of Nurse Practitioners Student Chapter for Michigan State University and continues her membership at the state level.

Prior to earning her graduate degree, she earned her Bachelors of Science in Nursing from University of Michigan-Flint. She began her nursing career as a Registered Nurse in 2009. Jessica worked in the capacity as a RN for eight years before receiving her masters’ degree. Her experience includes working in the intensive care unit, emergency department and was a leader on the code blue team in a level I trauma center. During this time she was nominated for the Aspiring Nurse Leader Award. Her overall work experience encompasses general medical, cardiovascular, emergency medicine and advanced cardiac life support.

Matthew Marsh, PA-C- CERTIFIED PHYSICIAN ASSISTANT

In 2008, Matthew received a Bachelor of Science in Clinical Laboratory Science from Southern Adventist University in Tennessee. After several years of hospital work he went on to Union College in Lincoln, Nebraska to receive a Masters of Physician Assistant Studies, graduating in 2013.

Prior to joining the Dermatology and Skin Surgery Center, he spent four years doing family practice, urgent care, general and orthopedic surgery on the island of Guam and the islands Micronesia. He continues to return annually to the islands to provide care to the local people.

Matthew works under the supervision of Dr. Donn LaTour and the other physicians at the Dermatology and Skin Surgery Center, with communication daily with the physicians. Matthew joined the Dermatology and Skin Surgery Center in 2017.