Transcript MOHS MICROGRAPHIC SURGERY: A HISTORICAL

MOHS MICROGRAPHIC SURGERY: A HISTORICAL PERSPECTIVE
Patricia Ting, BSc, Anatoli Freiman, MD
ABSTRACT
Division of Dermatology, McGill University Health Centre, Montreal, Canada
In the early 1930s, as a medical student at the University of Wisconsin, Fredric E. Mohs pioneered the idea of
INK DYES
microscopically-controlled removal of cutaneous tumours. With its ability to systematically examine 100% of lesion
Dr. Fredric E. Mohs
(1910-2000)
margins, Mohs Micrographic Surgery (MMS) allows for maximal sparing of normal tissues and provides excellent cosmetic
results. Whereas today, it is considered one of the greatest contributions to the field of dermatologic surgery, the
widespread acceptance of the technique took over 50 years. We review the key historical events and people involved in
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the development of MMS.
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THE BEGINNINGS
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Mohs refined his technique by color-coding the
specimen edges with:
– Red (merbromin)
– Blue (laundry dye)
– Black (India ink)
The addition of ink dyes provided a precise reference
map of the tumour to be drawn and juxtaposed upon
the corresponding surgical wound bed.
In the early 1930’s, as a young medical student at the University of Wisconsin, Frederic E. Mohs worked as an
assistant in a cancer research laboratory, investigating the effect of various irritants on implanted cancers in rats.
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FRESH TISSUE TECHNIQUE
Mohs observed that injections of 20% zinc chloride effectively and accurately penetrated the tissues without
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systemic toxicity. Furthermore, the chemical was also safe to handle, as it did not diffuse into the keratin layer of
procedure. A monumental change in Mohs fixed tissue technique serendipitously occurred in 1953 during the filming of
the skin, unless a keratolytic, such as dichloroacetic acid, was previously applied. Most importantly, this zinc
an instructional documentary demonstrating Dr. Allington’s suggestion on a multistage removal of an eyelid basal cell
preparation maintained the histologic architecture of tissues.
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carcinoma. Due to the time constraints of the filming session, Mohs injected the residual tumour area with local
Mohs subsequently proposed the concept of chemical fixation followed by surgical excision of tumors with
1st Meeting of the American College of Chemosurgery in 1967 (Chicago).
Front row & center: Dr. Fredric E. Mohs.
microscopic examination of tumor margins. And thus, the concept of micrographic chemosurgery was born.
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In 1936, after formal training as a general surgeon, Dr. Mohs began treating patients with cutaneous malignancies in
granular matrix) and sanguinaria canadenis (a binder for the saturated solution of zinc chloride).
ORIGINAL PROCEDURE FOR MOHS CHEMOSURGERY –
FIXED TISSUE TECHNIQUE (1936 – 1948)
1933
12
years
Figure 6. Diagrammatic
representation of
horizontal sections used in
Mohs technique.
Step 1: Injection of local anesthetic (Figure 1) .
Step 2: Removal and curettage of superficial tumour (Figure 2).
Source: Brodland et al. 2000
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absence of tissue inflammation and sloughing, which were previously observed secondary to zinc chloride application,
1936 Dr. Mohs begins using his technique at the Wisconsin General Hospital.
more tissue could be conserved and reconstruction of the wound bed could now take place on the same day as the
1941 Dr. Mohs reports 440 patients successfully treated with chemosurgery.
excision.
1953
1953 The fresh tissue technique used for the first time during the filming of an instructional documentary on Mohs
technique for the removal of eyelid tumours.
17
years
1956 Mohs technique appears in the 1st edition of Epstein’s Skin Surgery.
1966 Establishment of the first 1-year fellowship in Mohs surgery at NYU Medical Centre by Perry Robbins.
1970
Source: Mohs, FE. Chemosurgery – Microscopically
Controlled Surgery for Skin Cancer (1978).
ACCEPTANCE OF MOHS MICROGRAPHIC TECHNIQUE
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1970 Dr. Theodore Tromovitch reports successful results with the fresh tissue technique at the 4th American College of
Chemosurgery meeting.
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rates with this new technique, which also proved that the real reason for the success of the fresh-tissue Mohs
surgery was not the chemical fixation of the tissue, but the microscopic control.
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officially regulated via this organization.
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reconstructive surgery.
CONCLUSIONS
1991 Establishment of the American Board of Mohs Micrographic Surgery and Cutaneous Oncology.
Figure 5.
“Winning general acceptance takes much patience,” said Dr. Fredric Mohs.
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The development and widespread acceptance of Mohs micrographic surgery has taken over 50 years.
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Although the original concept of micrographic surgery began in the early 1930s, 12 years elapsed before the
INITIAL REJECTION OF MOHS FIXED TISSUE TECHNIQUE
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For residual neoplastic tissue, the process of fixation, surgical
excision and microscopic examination were repeated until the margins
cleared.
Between the 1930 – 1950s, Mohs’ pioneering surgical concept for the treatment of cutaneous malignancies was not well accepted by the
medical community for several reasons:
1. Patients complained of extreme pain due to the caustic effects of zinc chloride fixative, which induced edema and tissue necrosis
The defect was allowed to heal by secondary intention as the
fixative sloughed over the course of 7 to 10 days (Figure 7 & 8).
If required, skin grafts were performed after this time period.
* Mohs technique allowed for histological examination of entire base and
margins of the defect,
2. Local inflammation made it difficult to interpret tumour histopathology
3. Microscopic examination of the margins and repeating process for incompletely excised tumor was very labor intensive
4. Increased infection rates due to delayed surgical reconstruction and closure of wound bed/defect
Figure 7.
Figure 8.
Source: Mohs, FE. Chemosurgery – Microscopically Controlled Surgery for Skin Cancer (1978).
The Mohs surgery fellowship requires specialized training in a composite of skills including dermatopathology and
1985 American College of Chemosurgery renamed to American College of Mohs Micrographic Surgery and Cutaneous Oncology
(ACMMSCO).
Adapted from Brodland et al. 2000
Figure 4.
In 1986, the American College of Chemosurgery was renamed the American College of Mohs Micrographic Surgery
and Cutaneous Oncology (ACMMSCO) and minimum one-year fellowships in Mohs Micrographic Surgery were
1983 Minimum 1-year fellowships regulated by the American College of Chemosurgery.
Figure 3.
At the annual meeting in 1970, Dr. Theodore Tromovitch, who had been using the fresh tissue technique since the
1960s, presented a case series of 75 patients treated for cutaneous carcinomas and reported equally high cure
1974 Dr. Daniel Jones, a trainee of Dr. Mohs, coins the term “micrographic surgery."
1991
By the mid-1960s, Mohs technique gained wide acceptance, eventually leading to the establishment of American
College of Chemotherapy in 1967.
1969 Dr. Mohs presents a 100% cure rate for eyelid tumours using the fresh tissue technique at the 3rd American College of
Chemosurgery meeting.
1978 Textbook of Chemosurgery: Microscopically Controlled Surgery for Skin Cancer written by Dr. Mohs.
Figure 2.
With this procedural modification, patients experienced significantly less pain and morbidity. Because of the
1933 Fredric Mohs’ original concept of chemosurgery for cutaneous neoplasms.
1975 1st issue of the Journal of Dermatologic Surgery and Oncology published.
Figure 1.
It was soon realized that the resolution of tumor margins was not significantly impeded without fixation. This
Epstein’s Skin Surgery in 1956.
MILESTONES IN THE DEVELOPMENT OF MOHS MICROGRAPHIC SURGERY
1967 1st American College of Chemosurgery meeting with 23 attendees.
Step 4: Surgical excision of tumour in saucer-like horizontal
sections (Figure 6).
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1946 Mohs technique caught the attention of dermatologists at the American Academy of Dermatology meeting in Chicago.
Step 3: Application of dichloracetic acid (Figure 3) and in-situ zinc
chloride fixative paste for 12 to 24 hours (Figure 4 & 5).
Step 5: Microscopic examination of frozen sections.
anesthetic and omitted the second round of the zinc chloride fixation.
became known as the fresh-tissue technique, which was also illustrated in Mohs’ chapter in the 1st edition of
the dermatology clinic at the Wisconsin General Hospital. An elderly pharmacist at the drug store supplied him with
the ingredients required for the topical fixative paste containing stibinite (an antimony ore, which served as a
In 1951, Dr. Ray Allington suggested that dichloroacetic acid could be used for hemostatis after the debulking
5. Belief that cutting through the tumour would promote local seeding of tumour cells and metastatic spread
*Therefore, surgeons at the time preferred to use conventional wide surgical margins.
development of the original fresh tissue technique (1936 to 1948), and its use for cutaneous carcinomas did not
begin until 17 years later (1953 to 1970).
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With its ability to systematically examine 100% of tumour margins, Mohs Micrographic Surgery allows for maximal
sparing of normal tissues and provides excellent cosmetic results.
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Today, it is considered one of the greatest contributions to the field of dermatologic surgery.
ACKNOWLEDGEMENTS
Special thanks to Dr. Lawrence Warshawski, Dr. Dan Issen & Dr. David Zloty (Vancouver, BC) for the clinical photos and
to Dr. Channy Y. Muhn (Burlington, Ontario) for the inspiration.