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Surgical margins for excision of dermatofibrosarcoma protuberans
DERMATOLOGICSURGERY Surgical margins for excision of dermatofibrosarcoma protuberans Timothy L. Parker, MD, and John A. Zitelli, MD Overland Park, Kansas, and Pittsburgh,
Pennsylvania
Background: Dermatofibrosareoma protuberans (DFSP) commonly recurs after standard surgical excision with a wide margin, No studies have been undertaken to objectively determine the appropriate surgical margins by measuring the extension of the subclinical tumor. Objective: Our purpose was to measure the subclinical extent of tumor in 20 patients with DFSP to determine appropriate surgical margins. Methods: We mapped the subclinical tumor extension with Mohs micrographic surgery and measured the surgical margins required to clear the tumor completely. Results: We found that a 2.5 cm surgical margin through the deep fascia (nonscalp) or pe riosteum (scalp) cleared all of the tumors. DFSP tumors that measured less than 2 cm were completely cleared with a 1.5 cm surgical margin. None of our patients had a recurrence of the tumor, and in 16 of 20 patients primary repairs were possible. ConcZz&n: Our data support the use of Mohs surgery to excise DFSP with maximum conservation of tissue and a high cure rate. (J AM ACAD DERMATOL 1995;32:233-6.)
Dermatofibrosarcoma protuberans (DFSP) is characterizedby subclinicalextensionthat requires wide surgicalmargins to removeall of the tumor. It normally hasa benigncoursebut may rarely metastasizeto distant organs,especiallyafter repeatedrecurrences.’DFSP has a high recurrencerate after surgicalexcision(range,11% to 73%).‘-’ The literature includes 18 reportsof DFSP casesthat were successfullytreated with Mohs micrographic surgery.6-10 Surgical margins of 3 cm or more beyondthe tumor border arecurrently recommendedwhen standard surgery is used. This recommendationwas made predominantly on the basis of studies by McPeak et al.’ and Bendix-Hansenet a1.3that comparedthe relationshipof recurrenceratesto the surgical margin. McPeak et al. concludedthat a 3 cm lateral margin should be excisedthrough the deep fascia. This margin resulted in a recurrence rate of ( 10%)(8 of 82).Bendix-Hansenet al. excised at leasta l-inch margin throughthe deepfasciaand reportedno recurrencesin 19 patients.No studies From Shadyside Medical Center. Reprint requests:John A. Zitelli, MD, Shadyside Medical Center, 5200 Centre Ave., Suite 303, Pittsburgh, PA 15232. Copyright @ 1995 by the American Academy of Dermatology, Inc. Ot90-9622194 $3.00 + 0 6/l/60526
have beenundertakento measurethe histopathologic subclinicalmargins to determinemore objectively the appropriate surgical margin. We attemptedto defineappropriatemarginsof excisionon the basisof measurementsof subclinicaltumor extensionwith the Mohs micrographic technique. MATERIAL
AND METHODS
A retrospective study of 20 patients treated for DFSP from 1985 to 1993 with the Mohs micrographic technique was undertaken. The technique involved marking the clinically apparent margin around the tumor. The clinically apparent tumor was debulked with a scalpel; a layer of normal-appearing tissue of 0.4 to 1.Ocm in width was then removed around the entire wound margin. The margin of the tissue layer was examined in its entirety by microscopy and residual tumor was mapped to the exact location of the wound where it remained. This process was repeated only in the specific locations of the wound that still contained tumor. Further stages were performed until the entire margin was histologically clear of tumor. The wound was then reconstructed immediately. The margins were calculated by using the tumor map (drawn to scale) and adding the measured width of the tissue layers that were taken. The final layer taken had reached a tumor-free plane in each case. A common goal in treating skin malignancies is to reach a 5-year cure rate of 95%. Our goal for establishing a guideline for surgical margins was to determine the 233
Journal of the American Academy of Dermatology 234
Parker and Zitelli
February 1995
Clearance cumulative% 100
-
100
N=ZO
80 -
80
85
75
Margin of excision (cm) Fig. 1. Rate of tumor clearance for various margins of excision in 20 tumors.
Distribution accordingto tumor size
Table I.
LOCdiOll
Size
(cm)
o-2 2-4 >4
No.
%
9 8 3
45 40 15
minimum margin necessary to successfully remove all tumor in at least 95% of patients.t ’ We compared tumor size, location (head/neck or trunk), whether the tumor was primary or recurrent, and depth of tumor extension with the margin of excision needed for tumor clearance. We also looked at the overall recurrence rate and the type of reconstruction required to close the surgical defect. RESULTS
The patient’s agesranged from 20 to 64 years (mean, 37.7 years). Twelve of the patients had a primary (untreated)tumor, and eight patientshad a recurrent tumor. Tumor sizevariedfrom 1 to 10cm (Table I). The minimal lateral margin required for tumor clearancewasdeterminedfor eachlesion (Fig. 1). Margins of 2.5 cm were required to clear all of the tumors, and this was also the minimum surgical margin that would completely removeall tumor in 95% of patients.It is noteworthythat 75%of the tumors were completely cleared with only a 1.0 cm margin, 80% with a 1.5cm margin, and 85% with a 2.0 cm margin. The relation of tumor sizeto the minimum surgi-
Head/neck
3 2 2
TNnk
6 6 1
cal margin was determined (Fig. 2). The tumors weregroupedby diameter:lessthan 2 cm, 2 to 4 cm, and greaterthan 4 cm. A 1.5cm margin clearedall tumors with a diameterof 0 to 2 cm. A 2.5cm margin was requiredto clear all tumors greaterthan 2 cm in diameter. There wasno differencein the margin requiredto reachthe 95%tumor clearancestandardfor tumors onthe heador neckversustumorsonthe trunk. Both the heador neck andthe trunk locationsrequireda 2.5 cm surgical margin to completelyeradicatethe tumor in at least 95% of patients. When the sizeof the tumor in eachlocation was evaluatedfor minimal surgical margins, the three heador necktumors 2 cm or lessin diameterwere clearedwith only a 0.5 cm margin. However, a 2.5 cm margin wasstill necessaryto clear the largertumors. The tumors of the trunk that measuredless than 2 cm were cleared with a 1.5 cm margin, whereasthe tumors in the 2 to 4 cm rangedid not reachthe 95% clearancerate until a 2.5cm margin was reached. We compared the surgical margin required to clear the tumor with the type of tumor, that is, pri-
Journal of the American Academy of Dermatology Volume 32, Number 1, Part 1
Parker and Zitelli
235
Tumor Clearance cumulative % Tumor Size O-2cm N=9 @j 2-4cm N=8 q >4cm N=3
8o q
Fig.
61
63 f
Margin of excision (cm) 2. Rateof tumor clearanceasa functionof tumorsize.
mary or recurrent.The primary tumors weremore likely to be clearedwith a 0.5 cm margin (50% vs 12.5%),but to clear 95%of the tumorstherewasno differencein the surgical margin betweenprimary and recurrent tumors (Table 11). All of the tumors (exceptthoseon the forehead and scalp) were completely removed by cutting through the deep fascia and into the superficial musclelayer.The tumors on the scalpandforehead were completely removed by cutting through the periosteum. Primary closurewaspossiblein 16of 20 patients, including 5 of 7 with tumors in the head and neck area.The woundof onepatient wasrepairedwith a cheek advancementflap, and three patients had woundsthat weremanagedby secondintention(two on the trunk and one in the supraclaviculararea). None of the 20 patients with either primary or recurrent DFSP had a recurrencein this instance. The follow-up periodrangedfrom 3 months to 105 months, with a mean of 40.4 months. Standardx2 statisticalanalysiswasnot performedbecauseof the small number of patientsin the study. DISCUSSION
Historically, DFSP hasbeena difficult tumor to eradicate.Dismal recurrenceratesevenafter wide local excisionsand“salvagesurgeries”(further wide excisionsdone in the standard surgical manner) aboundin the literature. This is the first study to determine objectivelythe appropriatesurgicalmargin for this tumor by tracking subclinicaltumor exten-
Table II. Rate of tumor clearanceas a function of primary versusrecurrenttumor Surgical margin (cm)
Primary
Recmrent
W./W
ouo./%)
1(12S%)
0.5
6 (50%)
1.0
10(83%) 10(83%) 11(92%)
5 (63%) 6 (75%) 6 (75%)
12 (100%)
8 (100%)
1.5 2.0 2.5
sion with histopathologicmeasurements.We have shown that the use of a recommendedmargin of greaterthan 3 cm would have risked unnecessary removalof normal tissuein all 20 of our patients.In fact, we were able to completelyexcise80% of the tumors with a 1.5 cm margin. Although the clearancepercentagefor this margin is too low to recommend it for standardexcision,it documentssignificant tissue conservationcomparedwith the previously suggestedmargin. The fact that we cleared 100%of the tumors in our serieswithout a recurrencedemonstratesthat traditional pathologicexaminationof the margin in this tumor is much less reliable than the margin control with the Mohs technique.This study of 20 patients, although small, is the largest to date of DFSP tumors excisedby Mohs surgery. Our data suggestthat the sizeof the tumor is the most important variableaffecting surgicalmargins. Tumors lessthan 2 cm may be safelyexcisedwith
236
Parker and Zitelli
a 1.5 cm margin, as opposedto the 2.5 cm margin neededin larger tumors. The sizeof the margin requiredto clearthetumors in differentlocationsor for differenttypes(primary or recurrent)did not differ. Mohs surgeryoffersseveraladvantagesin removing DFSP tumors. With Mohs surgeryit is possible to conserveasmuch normal tissueaspossiblewhile still completely removing the tumor. All our patients’ tumors were clearedwith a margin of 2.5 cm or less;80%wereclearedwith only a 1.5cm margin. This resultsin a smaller woundthat requiresa less complicatedrepair.Previousreportshavestatedthat removalof most DFSP tumors requiresa skin graft to repair the wound.L 5We were ableto close 16of 20 woundsprimarily without skin grafting because we were ableto usethe narrowestmarginspossible. Mohs surgeryalsohas the highestcure rate of any modality usedfor DFSP. Our patientshavehad no recurrences(mean follow-up, more than 3 years), nor have any recurrencesof DFSP treated with Mohs surgerybeenreportedin the literature.6-10 REFERENCES
1. McPeak CJ, Cruz T, Nicastri AD. Dermatofibrosarcoma protuberans: an analysisof 86 cases,five with metastasis. Ann Surg 1967;166:803-16.
Journal of the American Academy of Dermatology February 1995
2. Taylor HB, Helwig EB. Dermatofibrosarcoma protuberans: a study of 115 cases.Cancer 1962;15:717-25. 3. Bendix-Hansen K, Myhre-Jensen 0, Kaae S. Dermatofibrosarcoma protuberans: a clinicopathological study of nineteen casesand a review of the world literature. Stand J Plast Reconstr Surg Hand Surg 1983;17:247-52. 4. RosesDR, Valensi Q, La Trenta G, et al. Surgical treatment of dermatofibrosarcomaprotuberans. Surg Gynecol Obstet 1986;162:449-52. 5. Mark RJ, Bailet JW, Tran LM, et al. Dermatofibrosarcoma protuberansof the head and neck:a report of 16cases. Arch Otolaryngol Head Neck Surg 1993;119:891-6. 6. M&hail GR, Lynn BH. Dermatofibrosarcoma protuberans. J Dermatol Surg Oncol 1978;4:81-4. 7. PetersCW, Hanke CW, PasarellHA, et al. Chemosurgical reports: dermatofibrosarcomaprotuberans of the face. J Dermatol Surg Oncol 1982;8:823-6. 8. Robinson JK. Dermatofibrosarcoma protuberans resected by Mohs’ surgery(chemosurgery)J AM ACADDERMATOL 1985;12:1093-8. 9. Hobbs ER, Wheeland RG, Bailm PL, et al. Treatment of dermatofibrosarcomaprotuberanswith Mohsmicrographic surgery. Ann Surg 1988;207:102-7. 10. Weber PJ, Gretzula JC, Hevia 0, et al. Dermatofibrosarcoma protuberans. J Dermatol Surg Oncol 1988;14:555-8. 11. Brodland DG, Zitelli JA. Surgicalmargins for excisionof primary cutaneoussquamouscell carcinoma. J AM ACAD DERMATOL1992;27:241-8.
Pennsylvania
Background: Dermatofibrosareoma protuberans (DFSP) commonly recurs after standard surgical excision with a wide margin, No studies have been undertaken to objectively determine the appropriate surgical margins by measuring the extension of the subclinical tumor. Objective: Our purpose was to measure the subclinical extent of tumor in 20 patients with DFSP to determine appropriate surgical margins. Methods: We mapped the subclinical tumor extension with Mohs micrographic surgery and measured the surgical margins required to clear the tumor completely. Results: We found that a 2.5 cm surgical margin through the deep fascia (nonscalp) or pe riosteum (scalp) cleared all of the tumors. DFSP tumors that measured less than 2 cm were completely cleared with a 1.5 cm surgical margin. None of our patients had a recurrence of the tumor, and in 16 of 20 patients primary repairs were possible. ConcZz&n: Our data support the use of Mohs surgery to excise DFSP with maximum conservation of tissue and a high cure rate. (J AM ACAD DERMATOL 1995;32:233-6.)
Dermatofibrosarcoma protuberans (DFSP) is characterizedby subclinicalextensionthat requires wide surgicalmargins to removeall of the tumor. It normally hasa benigncoursebut may rarely metastasizeto distant organs,especiallyafter repeatedrecurrences.’DFSP has a high recurrencerate after surgicalexcision(range,11% to 73%).‘-’ The literature includes 18 reportsof DFSP casesthat were successfullytreated with Mohs micrographic surgery.6-10 Surgical margins of 3 cm or more beyondthe tumor border arecurrently recommendedwhen standard surgery is used. This recommendationwas made predominantly on the basis of studies by McPeak et al.’ and Bendix-Hansenet a1.3that comparedthe relationshipof recurrenceratesto the surgical margin. McPeak et al. concludedthat a 3 cm lateral margin should be excisedthrough the deep fascia. This margin resulted in a recurrence rate of ( 10%)(8 of 82).Bendix-Hansenet al. excised at leasta l-inch margin throughthe deepfasciaand reportedno recurrencesin 19 patients.No studies From Shadyside Medical Center. Reprint requests:John A. Zitelli, MD, Shadyside Medical Center, 5200 Centre Ave., Suite 303, Pittsburgh, PA 15232. Copyright @ 1995 by the American Academy of Dermatology, Inc. Ot90-9622194 $3.00 + 0 6/l/60526
have beenundertakento measurethe histopathologic subclinicalmargins to determinemore objectively the appropriate surgical margin. We attemptedto defineappropriatemarginsof excisionon the basisof measurementsof subclinicaltumor extensionwith the Mohs micrographic technique. MATERIAL
AND METHODS
A retrospective study of 20 patients treated for DFSP from 1985 to 1993 with the Mohs micrographic technique was undertaken. The technique involved marking the clinically apparent margin around the tumor. The clinically apparent tumor was debulked with a scalpel; a layer of normal-appearing tissue of 0.4 to 1.Ocm in width was then removed around the entire wound margin. The margin of the tissue layer was examined in its entirety by microscopy and residual tumor was mapped to the exact location of the wound where it remained. This process was repeated only in the specific locations of the wound that still contained tumor. Further stages were performed until the entire margin was histologically clear of tumor. The wound was then reconstructed immediately. The margins were calculated by using the tumor map (drawn to scale) and adding the measured width of the tissue layers that were taken. The final layer taken had reached a tumor-free plane in each case. A common goal in treating skin malignancies is to reach a 5-year cure rate of 95%. Our goal for establishing a guideline for surgical margins was to determine the 233
Journal of the American Academy of Dermatology 234
Parker and Zitelli
February 1995
Clearance cumulative% 100
-
100
N=ZO
80 -
80
85
75
Margin of excision (cm) Fig. 1. Rate of tumor clearance for various margins of excision in 20 tumors.
Distribution accordingto tumor size
Table I.
LOCdiOll
Size
(cm)
o-2 2-4 >4
No.
%
9 8 3
45 40 15
minimum margin necessary to successfully remove all tumor in at least 95% of patients.t ’ We compared tumor size, location (head/neck or trunk), whether the tumor was primary or recurrent, and depth of tumor extension with the margin of excision needed for tumor clearance. We also looked at the overall recurrence rate and the type of reconstruction required to close the surgical defect. RESULTS
The patient’s agesranged from 20 to 64 years (mean, 37.7 years). Twelve of the patients had a primary (untreated)tumor, and eight patientshad a recurrent tumor. Tumor sizevariedfrom 1 to 10cm (Table I). The minimal lateral margin required for tumor clearancewasdeterminedfor eachlesion (Fig. 1). Margins of 2.5 cm were required to clear all of the tumors, and this was also the minimum surgical margin that would completely removeall tumor in 95% of patients.It is noteworthythat 75%of the tumors were completely cleared with only a 1.0 cm margin, 80% with a 1.5cm margin, and 85% with a 2.0 cm margin. The relation of tumor sizeto the minimum surgi-
Head/neck
3 2 2
TNnk
6 6 1
cal margin was determined (Fig. 2). The tumors weregroupedby diameter:lessthan 2 cm, 2 to 4 cm, and greaterthan 4 cm. A 1.5cm margin clearedall tumors with a diameterof 0 to 2 cm. A 2.5cm margin was requiredto clear all tumors greaterthan 2 cm in diameter. There wasno differencein the margin requiredto reachthe 95%tumor clearancestandardfor tumors onthe heador neckversustumorsonthe trunk. Both the heador neck andthe trunk locationsrequireda 2.5 cm surgical margin to completelyeradicatethe tumor in at least 95% of patients. When the sizeof the tumor in eachlocation was evaluatedfor minimal surgical margins, the three heador necktumors 2 cm or lessin diameterwere clearedwith only a 0.5 cm margin. However, a 2.5 cm margin wasstill necessaryto clear the largertumors. The tumors of the trunk that measuredless than 2 cm were cleared with a 1.5 cm margin, whereasthe tumors in the 2 to 4 cm rangedid not reachthe 95% clearancerate until a 2.5cm margin was reached. We compared the surgical margin required to clear the tumor with the type of tumor, that is, pri-
Journal of the American Academy of Dermatology Volume 32, Number 1, Part 1
Parker and Zitelli
235
Tumor Clearance cumulative % Tumor Size O-2cm N=9 @j 2-4cm N=8 q >4cm N=3
8o q
Fig.
61
63 f
Margin of excision (cm) 2. Rateof tumor clearanceasa functionof tumorsize.
mary or recurrent.The primary tumors weremore likely to be clearedwith a 0.5 cm margin (50% vs 12.5%),but to clear 95%of the tumorstherewasno differencein the surgical margin betweenprimary and recurrent tumors (Table 11). All of the tumors (exceptthoseon the forehead and scalp) were completely removed by cutting through the deep fascia and into the superficial musclelayer.The tumors on the scalpandforehead were completely removed by cutting through the periosteum. Primary closurewaspossiblein 16of 20 patients, including 5 of 7 with tumors in the head and neck area.The woundof onepatient wasrepairedwith a cheek advancementflap, and three patients had woundsthat weremanagedby secondintention(two on the trunk and one in the supraclaviculararea). None of the 20 patients with either primary or recurrent DFSP had a recurrencein this instance. The follow-up periodrangedfrom 3 months to 105 months, with a mean of 40.4 months. Standardx2 statisticalanalysiswasnot performedbecauseof the small number of patientsin the study. DISCUSSION
Historically, DFSP hasbeena difficult tumor to eradicate.Dismal recurrenceratesevenafter wide local excisionsand“salvagesurgeries”(further wide excisionsdone in the standard surgical manner) aboundin the literature. This is the first study to determine objectivelythe appropriatesurgicalmargin for this tumor by tracking subclinicaltumor exten-
Table II. Rate of tumor clearanceas a function of primary versusrecurrenttumor Surgical margin (cm)
Primary
Recmrent
W./W
ouo./%)
1(12S%)
0.5
6 (50%)
1.0
10(83%) 10(83%) 11(92%)
5 (63%) 6 (75%) 6 (75%)
12 (100%)
8 (100%)
1.5 2.0 2.5
sion with histopathologicmeasurements.We have shown that the use of a recommendedmargin of greaterthan 3 cm would have risked unnecessary removalof normal tissuein all 20 of our patients.In fact, we were able to completelyexcise80% of the tumors with a 1.5 cm margin. Although the clearancepercentagefor this margin is too low to recommend it for standardexcision,it documentssignificant tissue conservationcomparedwith the previously suggestedmargin. The fact that we cleared 100%of the tumors in our serieswithout a recurrencedemonstratesthat traditional pathologicexaminationof the margin in this tumor is much less reliable than the margin control with the Mohs technique.This study of 20 patients, although small, is the largest to date of DFSP tumors excisedby Mohs surgery. Our data suggestthat the sizeof the tumor is the most important variableaffecting surgicalmargins. Tumors lessthan 2 cm may be safelyexcisedwith
236
Parker and Zitelli
a 1.5 cm margin, as opposedto the 2.5 cm margin neededin larger tumors. The sizeof the margin requiredto clearthetumors in differentlocationsor for differenttypes(primary or recurrent)did not differ. Mohs surgeryoffersseveraladvantagesin removing DFSP tumors. With Mohs surgeryit is possible to conserveasmuch normal tissueaspossiblewhile still completely removing the tumor. All our patients’ tumors were clearedwith a margin of 2.5 cm or less;80%wereclearedwith only a 1.5cm margin. This resultsin a smaller woundthat requiresa less complicatedrepair.Previousreportshavestatedthat removalof most DFSP tumors requiresa skin graft to repair the wound.L 5We were ableto close 16of 20 woundsprimarily without skin grafting because we were ableto usethe narrowestmarginspossible. Mohs surgeryalsohas the highestcure rate of any modality usedfor DFSP. Our patientshavehad no recurrences(mean follow-up, more than 3 years), nor have any recurrencesof DFSP treated with Mohs surgerybeenreportedin the literature.6-10 REFERENCES
1. McPeak CJ, Cruz T, Nicastri AD. Dermatofibrosarcoma protuberans: an analysisof 86 cases,five with metastasis. Ann Surg 1967;166:803-16.
Journal of the American Academy of Dermatology February 1995
2. Taylor HB, Helwig EB. Dermatofibrosarcoma protuberans: a study of 115 cases.Cancer 1962;15:717-25. 3. Bendix-Hansen K, Myhre-Jensen 0, Kaae S. Dermatofibrosarcoma protuberans: a clinicopathological study of nineteen casesand a review of the world literature. Stand J Plast Reconstr Surg Hand Surg 1983;17:247-52. 4. RosesDR, Valensi Q, La Trenta G, et al. Surgical treatment of dermatofibrosarcomaprotuberans. Surg Gynecol Obstet 1986;162:449-52. 5. Mark RJ, Bailet JW, Tran LM, et al. Dermatofibrosarcoma protuberansof the head and neck:a report of 16cases. Arch Otolaryngol Head Neck Surg 1993;119:891-6. 6. M&hail GR, Lynn BH. Dermatofibrosarcoma protuberans. J Dermatol Surg Oncol 1978;4:81-4. 7. PetersCW, Hanke CW, PasarellHA, et al. Chemosurgical reports: dermatofibrosarcomaprotuberans of the face. J Dermatol Surg Oncol 1982;8:823-6. 8. Robinson JK. Dermatofibrosarcoma protuberans resected by Mohs’ surgery(chemosurgery)J AM ACADDERMATOL 1985;12:1093-8. 9. Hobbs ER, Wheeland RG, Bailm PL, et al. Treatment of dermatofibrosarcomaprotuberanswith Mohsmicrographic surgery. Ann Surg 1988;207:102-7. 10. Weber PJ, Gretzula JC, Hevia 0, et al. Dermatofibrosarcoma protuberans. J Dermatol Surg Oncol 1988;14:555-8. 11. Brodland DG, Zitelli JA. Surgicalmargins for excisionof primary cutaneoussquamouscell carcinoma. J AM ACAD DERMATOL1992;27:241-8.