The correspondence department of the ARCHIVES is meant to provide a forum for exchange of ideas about cutaneous medicine and surgery, and is divided into two sections. The comments and OPINIONS section is intended for responses to articles previously published in the journal or for com¬ ments on philosophic and practical issues pertaining to dermatology. If an Archives is discussed, the letter should contain this reference and be received within two months of the article's publication. The VIGNETTES section contains ministudies, very short case reports, rapid publications, and prelim¬ inary observations that lack the data to qualify as full journal articles. We encourage submission of letters for publication in the CORRESPONDENCE section. Acceptance is contingent on editorial review and space available. Correspondence should not exceed 500 words, con¬ tain more than five references and two figures, and must include a copyright transfer statement (see Information for Authors and Readers,) when submitted.


Micrographic Surgery and the Practitioner

To the Editor.\p=m-\DrRonald Rapini's editorial1 on Mohs surgery is his second2 thoughtful article on the subject in several years. However, many of his arguments are incorrect, and they certainly do not support the conclusion that there is anything uncertain in the definition of Mohs micrographic surgery (MMS). Foremost, I must take issue with his discussion of the bevel used in MMS. A 90\s=deg\bevel, as he advocates, precludes in continuity evaluation of margins. Axiomatic to MMS is the removal of a continuous layer of tissue (no buttonholes and complete epidermal edge) to irradicate a tumor that is continuous (no skip areas). Separating the histologic evaluation of "the edge" from "the base" violates this continuity. The geometry of such a technique would create a pathway for tumor to escape detection. What a leap of faith he asks of us to accept this approach based on his experience and an unpublished personal communication! I quickly surveyed six Mohs surgeons on reading this and found that (1) none used this technique, (2) several had not heard of it, and (3) no one con¬ sidered it MMS. To further support his contention of uncertainty, Rapini references several articles.3,4 In the first, Breuninger and Dietz3 review subclinical tumor extensions. Breuninger and Dietz do not represent their technique as MMS; rather, it is a modification thereof. No cure rates are discussed. In their "Materials and Methods" section, they cite a prior article5 detailing their technique. The title professes their technique an alternative to Mohs'." Its vague resemblance to to be MMS, therefore, is only that—they make no attempt to por¬ tray it as MMS. A careful reading of the article by McGillis et al4 reveals discussion mainly of sterile technique and instrumentation. It is disingenuous to characterize this arti¬ cle as proposing "extensive modifications of MMS from within the College." I would agree that there are several newer procedures that vaguely resemble MMS, such as "in continuity peripheral margins" or double knife blade excisions. These, however, are not usually presented as MMS; rather, they are an alterna¬ tive to it. Representing these as MMS is clearly in error. There are, of course, minor differences within the college, such as which stain is used and exactly how the tissue is mapped or is color coded. These variations, though, are more "


similar to what I imagine one would find among orthopedists perfroming hip replacement surgery or cardiovascular sur¬ geons performing a coronary artery bypass. The importance, of course, of all of these fine differentia¬ tions is the cure rate published in the scientific literature. The articles documenting the high cure rate of MMS are too nu¬ merous to list. They truly form one of the pillars that support dermatologie surgery. All the aforementioned techniques lack that rigorous scientific documentation. That is not to say that they are not useful techniques. Many of them are. Not all tu¬ mors require the rigors of MMS. But before these other tech¬ niques are summarily lumped together with MMS they must be shown to have the same high cure rate as MMS. I know that if I develop a morpheaform basal cell carcinoma of the inner canthus I will want MMS. Somehow a double knife blade will suspect Dr Rapini would make the same choice. John J. Ghidoni, MD 3708 Jefferson Suite 103 Austin, TX 78731

not do. I

1. Rapini RP. On the definition of Mohs surgery and how it determines appropriate surgical margins. Arch Dermatol. 1992;128:673-678. 2. Rapini RP. Pitfalls of Mohs' micrographic surgery. J Am Acad Derma-

tol. 1990;23:681-686. 3. Breuninger H, Dietz K. Predicition of subclinical tumor infiltration in basal cell carcinoma. J Dermatol Surg Oncol. 1991;17:574-578. 4. McGillis ST, Wheeland RG, Sebben JE. Current issues in the performance of Mohs' micrographic surgery. J Dermatol Surg Oncol. 1991;17:681-684. 5. Breuninger H, Schaumburg-Lever G. Control of excisional margins by conventional histopathological techniques in the treatment of skin tumors: an alternative to Mohs' technique. J Pathol. 1988;154:167-71.

The Subtleties of Mohs


To the Editor.\p=m-\Iread Rapini's1 editorial in the May 1992 isof the Archives and found some of his suggestions concerning modifications of the Mohs technique worrisome. There are subtleties of Mohs surgery that are not readily apparent to observers that were not discussed and that bear directly on the enormous success of this procedure. Mohs surgeons insist that tissue be excised obliquely and sectioned horizontally with lateral and deep margins in the same plane and that all slides be reviewed by the surgeon. The purpose of these rigid guidelines is to enable the surgeon examining the slides to develop a three-dimensional mental image of the tumor. It is this mental image that the surgeon carries back to the operating room that gives Mohs surgery uniformly high cure rates no matter how complicated the case. In difficult tumors, it is not sufficient for the surgeon to sue

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know only if specimen A or B contains tumor. The surgeon must also know whether tumor is present at a skin edge, tracking horizontally in muscle or deep dermis, following a nerve,



fatty septum,


sliding along perichon-

drium. It is this awareness that separates Mohs surgery from all other techniques. A critical feature of Mohs surgery is assuring that the slides being examined contain a complete representation of the tissue that was removed. This task cannot be performed effectively by someone not present during surgery. Every time an excised specimen is subdivided, there is a chance tu¬ mor will be missed in the seam. This can occur because of tis¬ sue curling after excision and not being flattened by the technician or because of failure of the technician to face the tissue block exactly parallel to the blade. These shortcomings will be more apparent to the surgeon reading his or her own slides and much more easily corrected if the surgeon directly supervises the laboratory. The modifications suggested by Rapini will hinder these critical aspects of Mohs surgery. I agree, however, that not all tumors require such a narrowly defined procedure. The treatment of primary basal cell carcinoma and recurrent basal cell carcinoma confined to the skin is basically a two-dimensional problem. The third dimension, depth, is of lesser concern because excision to the underlying fat ade¬ quately removes the deep tumor in virtually all cases. Liber¬ ties can, therefore, be taken with margin checks without a fall in cure rates. Complex recurrent tumors and some primary tumors involving complex structures such as the eyelids, ears, and nose are true three-dimensional problems because of the ability of tumor to infiltrate any underlying tissue. Mohs surgery does not need to be redefined. Instead, Mohs surgeons and dermatologists need to agree on the narrow range of tumors that truly need this procedure. The remain¬ der can be treated by any reasonable modification of Mohs surgery, but the name "Mohs" should remain quite specific. Any third-party payer buying Mohs surgery for a client should reliably get the "real McCoy." George B. Winton, MD Department of Medicine (Dermatology) James H. Quillen College of Medicine East Tennessee State University Johnson City, TN 37604 1. Rapini RP. On the definition of Mohs' surgery and how it determines appropriate surgical margins. Arch Dermatol. 1992;128:673-678.

Redefinition of Mohs

Number of Microscopic Sections Required for Examination of Small Tumors*


To the Editor.\p=m-\DrRapini's editorial on Mohs Surgery1 was both disturbing and provocative. I am concerned that a dermatopathologist who is obviously very critical of Mohs surgery should be given an opportunity to redefine Mohs surgery. Several of Dr Rapini's statements deserve comment. I am surprised to hear that complete marginal examination was an "ancient rite" practiced for "decades" by other specialties. Dr Mohs began complete marginal examination in 1936 and was maligned and criticized for years for his tech-

nique. Through dogged determination and meticulous record keeping, Dr Mohs was able to show the merit of Mohs

surgery. Dr Rapini suggests in his editorial that Mohs surgeons excise too much tissue. Tissue preservation using Mohs surgery for treatment of skin cancers has been well demonstrated by Bumsted and Ceilley.2 They evaluated the size of the proposed excision using conventional surgery vs the actual defect using Mohs surgery for 71 patients with skin cancers


Method Bread-loaf method Bread-loaf-cross Peripheral vertical


vertical and horizontal Bread-loaf-cross with peripheral sections Mohs

No. of Sections





No No


Lateral, yes


Yes Yes






*Methods of tissue examination for small tumors as outlined



of the ear larger than 1 cm. Conventional surgery would have resulted in an average excess excision of 180% in primary le¬ sions and 347% in recurrent lesions (range of 78% to 1051%). Of greater concern, conventional surgery would have re¬ sulted in incomplete tumor excision in 24% of the patients.2 Dr Rapini is also critical of the Mohs surgeon acting as the pathologist. One of the key advantages of Mohs surgery is its efficiency and accuracy in processing tissue specimens. An outside histopathology laboratory cannot provide the rapid turnaround of multiple specimens necessary in an active Mohs clinic. Moreover, the cost of Mohs surgery is less than the cost of skin cancer excision plus the histologie examina¬ tion of multiple Mohs specimens. Dr Rapini's implication that greed is the motivation for Mohs surgery is irresponsible. Mohs surgery is used because it clearly has the highest cure rate for treating most skin cancers. Dr Rapini proposes, however, that Mohs surgery be redefined so that physicians who do not have the expense of a Mohs laboratory, who cannot assure full margin control, and cannot provide timely microscopic examination be allowed to collect for "Mohs surgery." Greed as a motivation for treat¬ ment hurts all of us as physicians and should not be accept¬ able in any field of medicine. Dr Rapini proposes that Mohs surgery be redefined as "a meticulous check of surgical margins." Dr Rapini previously reviewed alternate methods for microscopic examination of tumor margins.3 Bread-loaf sectioning, "the workhorse most commonly used by most laboratories for small specimens,"3 may examine only a small percentage of the tumor border. More complete examination more than doubles the number of microscopic sections needed for complete examination when compared with Mohs surgery (Table). This undoubtedly adds to the time, cost, complexity, and chance of errors. Dr Rapini hopesfor a cure rate of "90% to 95%" in basal cell carcinomas with these methods. Mohs surgery has a documented 5-year cure rate of 99% in primary4 and 94.4% in recurrent basal cell


On the positive side, Dr Rapini does assume the value of meticulous examination of tumor margins to maximize the cure rate of skin cancers. Any method that seeks to maximize cure rates is to be commended and encouraged. However, to diffuse the clear definition of Mohs surgery by redefining it as the "meticulous check of surgical margins" is counterpro¬ ductive. What precisely is the "meticulous check of surgical margins"? Who does these meticulous checks? Can the sur¬ geon be assured that 100% of the margin is being examined? Can this be done in a timely fashion? Can this be done in a cost-effective fashion? What are the 5-year cure rates using these meticulous methods? Alternate methods of tumor ex¬ cision should not be discouraged, but, to clearly evaluate the

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The subtleties of Mohs surgery.

The correspondence department of the ARCHIVES is meant to provide a forum for exchange of ideas about cutaneous medicine and surgery, and is divided i...
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