Mohs Micrographic Surgery Stages Research Articles

Factors Influencing Margin Clearance and the Number of Stages of Mohs Micrographic Surgery in Basal Cell Carcinoma: A Retrospective Chart Review.

How patient and tumor factors influence clearance margins and the number of Mohs Micrographic Surgery (MMS) stages when treating basal cell carcinoma (BCC) remains widely uncharacterized. It is important to elucidate these relationships, as surgical outcomes may be compared nationally between colleagues. Our objective is to evaluate the relationships between defect size and patient demographics, as well as between BCC subtypes and the number of MMS stages. Our second objective is to compare practice patterns and characteristics of patients requiring MMS at academic centers and private practices. A retrospective chart review was performed using data collected at academic centers (2015-2018) and private practices (2011-2018) of BCC patients older than 18 years old who underwent MMS. In total, 7651 patients with BCC requiring MMS were identified. Academic center adjusted analyses demonstrated clearance margins 0.1 mm higher for every year's increase in age (p < 0.0001) and 0.25 increase in MMS stages for high-risk BCC (p < 0.0001). Private practice adjusted analyses demonstrated clearance margins 0.04 mm higher for every year's increase in age (p < 0.0001). Clearance margins correlate with older age, and additional MMS stages correlate with high-risk BCC, suggesting the role patient and tumor factors may play in predicting tumor clearance and MMS stages.

Using optical coherence tomography to optimize Mohs micrographic surgery

Mohs micrographic surgery (MMS) is considered the gold standard for treating high-risk cutaneous basal cell carcinoma (BCC), but is expensive, time-consuming, and can be unpredictable as to how many stages will be required or how large the final lesion and corresponding surgical defect will be. This study is meant to investigate whether optical coherence tomography (OCT), a highly researched modality in dermatology, can be used preoperatively to map out the borders of BCC, resulting in fewer stages of MMS or a smaller final defect. In this prospective study, 22 patients with BCC undergoing surgical excision were enrolled at a single institution. All patients had previously received a diagnostic biopsy providing confirmation of BCC and had been referred to our center for excision with MMS. Immediately prior to performing MMS, OCT was used to map the borders of the lesion. MMS then proceeded according to standard protocol. OCT images were compared to histopathology for agreement. Histopathologic analysis of 7 of 22 MMS specimens (32%) revealed a total absence of BCC, indicating resolution of BCC after previous diagnostic biopsy. This outcome was correctly predicted by OCT imaging in 6 of 7 cases (86%). Nine tumors (9/22, 41%) had true BCC and required a single MMS stage, which was successfully predicted by pre-operative OCT analysis in 7 of 9 cases (78%). The final six tumors (27%) had true BCC and required two MMS stages for complete excision; preoperative OCT successfully predicted the need for a second stage in five cases (5/6, 83.3%). Overall, OCT diagnosed BCC with 95.5% accuracy (Cohen’s kappa, κ = 0.89 (p-value = < 0.01) in the center of the lesion. Following a diagnostic biopsy, OCT can be used to verify the existence or absence of residual basal cell carcinoma. When residual tumor is present that requires excision with MMS, OCT can be used to predict tumor borders, optimize surgery and minimize the need for additional surgical stages.

Outcomes of Squamous Cell Carcinoma of the Lip Treated With Mohs Micrographic Surgery: A Retrospective Cohort Study.

Cutaneous squamous cell carcinomas (cSCCs) of the lip have been reported to be at higher risk for poorer post-treatment outcomes. To examine outcomes of patients with SCC of the lip treated with Mohs micrographic surgery (MMS) and identify factors for recurrence. This retrospective review of a single tertiary referral center's Mohs case logs from 2010 to 2019 identified cases of lip SCC. Clinicopathologic characteristics and outcomes (local recurrence [LR], metastasis, and disease-specific death) were reviewed. One hundred ninety cases of SCC of the lip were identified and demonstrated that MMS offered a disease-free survival of 96.8% over an average follow-up period of 42 months. Younger age (61 vs 74 years p = .006), increased MMS stages ( p = .009), and higher American Joint Committee on Cancer and Brigham and Women's Hospital T stages were risk factors for LR. Immunosuppression, large tumor size, mucosal lip involvement, aggressive histology, and perineural invasion were not associated with LR. The results of this study show that SCC of the lip behaved similarly to cSCC outside the lip area, and that both primary and recurrent lesions can be treated effectively with MMS.

Mohs micrographic surgery for keratinocyte carcinomas: clinicopathological predictors of the number of stages

Background The number of Mohs stages needed to remove a keratinocyte carcinoma affects resource use, expenses, and repair complexity. This study aimed to identify clinicopathological predictors associated with increased or decreased stages and areas for further research. Methods A retrospective review was conducted from a single private practice with two Mohs surgeons of 2788 consecutive Mohs cases between January 2017 and December 2021, analyzing the average number of stages taken versus national norms (P = 0.21) and subgroups using unpaired t tests (*<0.05). Results Several tumor features were significantly associated with fewer stages: squamous cell carcinomas, Mohs appropriate use criteria score of 7 or 8, preoperative size <0.25 cm2, tumors on the lips and extremities (including hands/fingers), and smoking. Clinicopathological features significantly associated with more stages included Mohs appropriate use criteria score of 9, recurrent skin cancers, basal cell carcinomas, tumor size of 2.25–3.99 cm2, cancers on ears, solid organ transplant patients, treatment delays >180 days, and patients ≥90 years old. Conclusions Significant predictors exist for both increased and decreased numbers of Mohs micrographic surgery stages required to eradicate a tumor, which may help Mohs surgeons facilitate, plan, and allocate resources more effectively. Areas for further research in Mohs micrographic surgery are identified.

Predictors of patient satisfaction with Mohs micrographic surgery at time of surgery and 3 months postsurgery: A prospective cohort study

Despite the importance of patient satisfaction in ensuring high-quality care, studies investigating patient satisfaction in Mohs micrographic surgery (MMS) are limited. We investigated the factors associated with patient satisfaction in MMS for nonmelanoma skin cancer and how patient satisfaction changes in the postoperative period. In this prospective cohort study including 100 patients, patient satisfaction surveys were administered at the time of surgery and at 3months postsurgery. Sociodemographic characteristics, medical history, and surgical parameters were collected by chart review. Univariate linear and logistic regression models were created to examine these relationships. Decreased satisfaction was observed in patients requiring 3 or more MMS stages both at the timeof surgery (P=.047) and at 3months post-surgery (P=.0244). Patients with morning procedures ending after 1:00 pm had decreased satisfaction at the time of surgery (P=.019). A decrease in patient satisfaction between the time of surgery and 3months postsurgery was observed in patients with surgical sites on the extremities (P=.036), larger preoperative lesion sizes (P=.012), and larger defect sizes (P=.033). Single-institution data, self-selection bias, and recall bias. Patient satisfaction with MMS is impacted by numerous factors and remains dynamic over time.

Use of hemostatic clips to reduce blood loss in between Mohs micrographic surgery stages

Use of hemostatic clips to reduce blood loss in between Mohs micrographic surgery stages

Pain of local anesthetic injection of lidocaine during subsequent stages of Mohs micrographic surgery: A multicenter prospective cohort study

Patients awake during staged cutaneous surgery procedures may experience procedure-related pain. To determine whether the level of pain associated with local anesthetic injections prior to each Mohs stage increases with subsequent Mohs stages. Multicenter longitudinal cohort study. Patients rated pain (visual analog scale: 1-10) after anesthetic injection preceding each Mohs stage. Two hundred fifty-nine adult patients presenting for Mohs who required multiple Mohs stages at 2 academic medical centers were enrolled; 330 stages were excluded due to complete anesthesia from prior stages, and 511 stages were analyzed. Mean visual analog scale pain ratings were nominally but not significantly different for subsequent stages of Mohs surgery (stage 1: 2.5; stage 2: 2.5; stage 3: 2.7: stage 4:2.8: stage 5: 3.2; P=.770). Between 37% and 44% experienced moderate pain, and 9.5% and 12.5% severe pain, during first as versus subsequent stages (P>.05) LIMITATIONS: Both academic centers were in urban areas. Pain rating is inherently subjective. Patients did not report significantly increased anesthetic injection pain level during subsequent stages of Mohs.

Dermoscopic and Histopathologic Analysis of the Correlation between the Pigmentation of Basal Cell Carcinoma and Tumor Aggressiveness.

Basal cell carcinoma (BCC) is the most common type of skin cancer. In patients with darker skin, most BCCs are pigmented. Studies suggest that increased pigmentation in BCC may be inversely associated with tumor aggressiveness. This study analyzed the dermoscopic features and histopathologic patterns of BCCs to evaluate the correlation between BCC pigmentation and tumor aggressiveness. A total of 76 BCC lesions were included in this retrospective study. The Mohs micrographic surgery (MMS) stage and tumor depth were measured as indices of tumor aggressiveness. The Fontana-Masson stain was performed for the identification of melanin, and immunohistochemical analysis was performed using Melan-A and HMB-45 to identify melanocytes. In MMS stage 1, the dermoscopic pigmentation value was 34.48%±14.22% (mean±standard deviation). In MMS stages 2 and 3, dermoscopic pigmentations were 13.72%±7.54% and 15.50%±17.52%, respectively. In the logistic regression model, higher dermoscopic pigmentation (95% confidence interval [CI], 0.68~0.99), melanin (95% CI, 0.63~0.89), and melanocyte-stained areas (95% CI, 0.70~0.92) were associated with a lower possibility of BCC tumor infiltration over the middle and lower layers. We found an inverse correlation between the pigmentation and aggressiveness of BCCs. Clinicians can predict the subclinical infiltration depth of BCC on the basis of the pigmentation observed on dermoscopy. Pigmentation can be considered a favorable prognostic factor for BCC.

Second-Intention Healing in Mohs Micrographic Surgery: A Single-Center Academic Experience.

To describe the trends in second-intention healing (SIH) use at a single Mohs micrographic surgery (MMS) dermatology clinic and assess outcomes and patient satisfaction. The authors conducted a single-center, retrospective study of patients who underwent MMS from November 2012 through November 2018. Data obtained for each patient included sex, age, tumor characteristics, number of MMS stages, final defect size, and postoperative complications. Patient satisfaction of SIH was retrospectively assessed by telephone survey. Providers used SIH in 22% of all MMS cases (n = 159/718). It was most commonly used for defects located on the nose, ear, temple, and periocular region. The average defect size and number of MMS stages for tumor clearance were 1.3 cm and 1.5 stages, respectively. Overall, low rates of postoperative complications were observed, and 95% of patients reported optimal or acceptable levels of satisfaction. This study supports the idea that SIH is a safe, effective alternative for wound management and may have broader practice indications than those traditionally proposed.

Evaluation of Pain After Mohs Micrographic Surgery: A Prospective Study.

Mohs micrographic surgery (MMS) is a widely used technique for removal of cutaneous tumors. The procedure is well-tolerated with little surgical or postoperative pain. This study examined pain levels after Mohs surgery throughout the first week of recovery and the relation to patient demographics, lesion characteristics, surgery details, and postoperative analgesia. A 2-year prospective observational study included patients who underwent MMS. Patients rated the severity of postoperative pain once daily until removal of sutures and documented analgesics used. Analyses of patient and lesion characteristics along with reconstruction methods were conducted. A total of 2,178 patients were included in the study. Pain levels were strongest on the first postoperative day (POD) and were significantly different between genders on POD 3. Site of skin lesion, method of reconstruction, and number of stages of MMS were significantly related to postoperative pain levels on univariate and multivariate analyses. Postoperative consumption of analgesics differed significantly between men and women and was not correlated to age. Mohs surgery is generally nonpainful and is well-tolerated by men and women across all ages. The site of the lesion and method of reconstruction are the major determinants affecting the perception of pain.

Predicting Mohs surgery complexity by applying machine learning to patient demographics and tumor characteristics.

Mohs micrographic surgery (MMS) is considered the gold standard for difficult‐to‐treat malignant skin tumors, whose incidence is on the rise. Currently, there are no agreed upon classifiers to predict complex MMS procedures. Such classifiers could enable better patient scheduling, reduce staff burnout and improve patient education. Our goal was to create an accessible and interpretable classifier(s) that would predict complex MMS procedures. A retrospective study applying machine learning models to a dataset of 8644 MMS procedures to predict complex wound reconstruction and number of MMS procedure stages. Each procedure record contained preoperative data on patient demographics, estimated clinical tumor size prior to surgery (mean diameter), tumor characteristics and tumor location, and postoperative procedure outcomes included the wound reconstruction technique and the number of MMS stages performed in order to achieve tumor‐free margins. For the number of stages complexity classification model, the area under the receiver operating characteristic curve (AUROC) was 0.79 (good performance), with model accuracy of 77%, sensitivity of 71%, specificity of 77%, positive prediction value (PPV) of 14% and negative prediction value (NPV) of 98%. The results for the wound reconstruction complexity classification model were 0.84 for the AUROC (excellent performance), with model accuracy of 75%, sensitivity of 72%, specificity of 76%, PPV of 39% and NPV of 93%. The ML models we created predict the complexity of the components that comprise the MMS procedure. Using the accessible and interpretable tool we provide online, clinicians can improve the management and well‐being of their patients. Study limitation is that models are based on data generated from a single surgeon.

Correlation of basal cell carcinoma subtype with histologically confirmed subclinical extension during Mohs micrographic surgery: A prospective multicenter study

Traditionally "aggressive" histologic subtypes (HSs) of basal cell carcinoma (BCC) are more likely to quantitatively exhibit subclinical extension (SCE), requiring more stages during Mohs micrographic surgery (MMS) and, therefore, larger margins upon excision. However, the tendency for SCE has never been compared between HSs of BCC in a prospective manner. To prospectively correlate the HS of BCC with the likelihood of SCE as defined by the number of MMS stages required to clear the tumor. In a prospective, multicenter study involving 17 Mohs surgeons in 16 different practices across the United States, data regarding 1686 cases of BCC undergoing MMS were collected. Patient demographics, tumor characteristics, number of MMS stages required for tumor clearance, and specific BCC subtypes noted on both index biopsy and the final MMS stage were recorded. Analysis of the average number of MMS stages for each HS required to clear tumor revealed 2 distinct degrees of SCE (P<.0001): high (higher than average) risk of SCE (1.9 stages, 1.0 SD) and low (lower than average) risk of SCE (1.6 stages, 0.9 SD). Subtypes of BCC within the high category were morpheaform (2.1), infiltrative (1.9), metatypical (1.9), mixed (1.8), and superficial (1.8). The low category included BCC subtypes of basosquamous (1.6), micronodular (1.6), nodular (1.6), and unspecified (1.5). Three hundred twenty-four cases (22.0%) manifested HS drift or a change in subtype from index biopsy to the final MMS stage. Superficial BCC was the only subtype that showed an increase in prevalence from index biopsy to the final MMS stage (from 16.0% to 25.8%; P<.0002). HSs from index biopsy may not be representative of all HSs present, resulting in sampling bias. SCE of superficial BCC was as likely as SCE of BCC subtypes that are considered "aggressive" and are deemed "appropriate" for MMS by the appropriate use criteria. Our study also found that when HS drift occurs, the most likely subtype to extend subclinically is superficial BCC.

Factors affecting outcomes of second intent healing of nasal defects after Mohs micrographic surgery.

Reconstruction of nasal defects secondary to Mohs micrographic surgery (MMS) presents particular challenges related to the complex topography, skin quality, tissue laxity, and functional and aesthetic concerns of the region. Factors affecting outcomes resulting from second intent healing (SIH) on the nose have not been well described. The purpose of the study was to identify factors impacting outcomes of SIH for nasal tumors following MMS. Retrospective analysis was performed of all nasal lesions treated with MMS followed by SIH from a single surgical center over a 1.5-year period. Ninety-six cases were included. Chart review was performed, and data were collected including age, gender, nasal site, tumor type, defect size, depth, and number of MMS stages. Pre- and post-operative follow-up photographs were available for all cases. All five authors evaluated the photographs using the modified Manchester scar scale. Analysis was then conducted to identify features associated with good outcomes. Of the 96 tumors, 39 lesions (40.6%) were located on the nasal tip (including supratip), 32 (33.3%) on the ala/alar groove, 17 (17.7%) on the sidewall, and 8 (8.3%) on the dorsum. The average defect size was 0.83 cm2 (diameter of 1.06cm ± 0.4). Defect diameter and defect depth were the factors that significantly impacted scar outcome (p < 0.001) in multivariate analysis. No significant functional deficits were reported. This retrospective study suggests that nasal defects with area less than 0.83 cm2 (or 1.06cm diameter) and depth of defect not extending beyond the superficial fat healed well by SIH regardless of location on the nose.

Determination of Margins for Tumor Clearance in Dermatofibrosarcoma Protuberans: A Single-Center Study of 222 Cases Treated With Modified Mohs Surgery.

Dermatofibrosarcoma protuberans (DFSP) is an invasive skin tumor traditionally associated with very high recurrence rates when treated with conventional surgery (CS). To calculate the minimum margin that would have been required to achieve complete tumor clearance with hypothetical CS. To analyze DFSP characteristics and Mohs micrographic surgery (MMS) effectiveness in treatment of this tumor. Minimum margin was calculated by measuring the largest distance from the visible edge of the tumor to the edge of the surgical defect. Tumor variables (age, sex, size, time since onset, and location) were correlated with surgical variables (number of stages and minimum margin). We studied 222 cases of DFSP treated with MMS. A mean of 1.47 MMS stages and a mean minimum margin of 1.23 cm were required to achieve tumor clearance. Tumors on the head and neck required significantly more stages and a significantly wider margin. Tumor size was positively correlated with time to diagnosis, age, and number of MMS stages. Tumors located on the head and neck have greater subclinical extension. Tumor size was also a predictor of surgical difficulty, but time to diagnosis was not.

Histopathologic upgrading of cutaneous squamous cell carcinomas during Mohs micrographic surgery: A retrospective cohort study

Initial biopsies of cutaneous squamous cell carcinomas (cSCCs) may not reveal aggressive histologic features, which would otherwise inform appropriate surgical management and patient education. To assess the incidence of, and risk factors for, histopathologic upgrading of cSCC during Mohs micrographic surgery (MMS). This was a retrospective cohort study of invasive cSCCs treated with MMS between 2017 and 2019 at 1 academic institution. An "upgrade" was defined as a lesser degree of differentiation (poor or moderate) and/or bony or perineural invasion identified during MMS that was not reported in histopathologic evaluation of the initial biopsy. Of the 1558 tumors studied, 115 (7.4%) were upgraded during MMS. In multivariate logistic regression analysis, male sex, prior field treatment, location on the ear/lip, rapid growth of cSCC, and tumor diameter ≥2cm were significant predictors of tumor upgrading. Upgraded tumors were more likely to require ≥3 MMS stages to clear, complicated closure (flap or graft), or outside (referral) repairs. Single-center study, retrospective, and inter-rater variability. A significant proportion of cSCCs is histopathologically upgraded with more aggressive features during MMS. Routinely documented patient and tumor characteristics can predict tumor upgrading and assist clinicians in directing the management of potentially high-risk cSCC patients.

Utility of Debulk Specimens During Mohs Micrographic Surgery for Cutaneous Squamous Cell Carcinoma

Limited literature exists regarding whether intraoperative analysis of frozen debulk specimens during Mohs micrographic surgery (MMS) improves identification of high-risk features (HRF) of cutaneous squamous cell carcinoma (CSCC). Primary: identification of new HRF on debulk specimens. Secondary: CSCC upstaged after considering debulk data. A single-center, retrospective cohort study of patients with biopsy-proven CSCC treated by MMS with intraoperative frozen debulk analysis. Restricted (poor differentiation, new perineural invasion ≥0.1 mm, and Breslow depth >6 mm) and nonrestricted (any worsened tumor differentiation, any new perineural invasion, and Breslow depth >2 mm) analyses were performed. In restricted analysis, 3.94% of cases had 1 new HRF on debulk analysis. In nonrestricted analysis, 32.9% of cases had ≥1 new HRF; 7.6% increased by 2 HRF. Approximately 2.0% of cases were upstaged by American Joint Committee on Cancer system, eighth edition criteria, 1.4% by Brigham and Women's Hospital. Tumor size ≥2 cm, male sex, and moderate differentiation on biopsy were significantly associated with new HRF identified on debulk analysis. Intraoperative frozen debulk analysis can reveal HRF of CSCC not seen on biopsy or MMS stages, particularly among tumors ≥2 cm. American Joint Committee on Cancer system, eighth edition T2 tumors were most likely to be upstaged. Identification of new HRF on debulk analysis can improve CSCC staging and may impact patient treatment and follow-up.

Characteristics of Superficial Basal Cell Carcinomas Containing More Aggressive Subtypes on Final Histopathologic Diagnosis.

The prognosis and treatment of basal cell carcinoma (BCC) are largely dependent on tumor subtype, which is typically determined by punch or shave biopsy. Data regarding concordance between BCC subtype on initial biopsy and final histopathology for Mohs micrographic surgery (MMS) or excision with frozen sections (EFS) are limited. To determine the concordance between initial biopsy and final MMS or EFS subtyping of BCC. We aim to investigate the incidence and clinical characteristics of lesions initially diagnosed as superficial BCC (sBCC) that are later found to have a nodular, micronodular, or infiltrative component. We conducted a retrospective review of all MMS or EFS cases performed at a single academic center from August 1, 2015 to August 31, 2017. Inclusion criteria were a biopsy-proven diagnosis of sBCC and presence of residual tumor following stage I of MMS or EFS. Fisher&rsquo;s exact test was used to evaluate significance of clinical characteristics and outcomes associated with the presence of a nodular, micronodular, or infiltrative BCC component. A total of 164 MMS or EFS cases had an initial biopsy showing sBCC. Of these, 117 had residual BCC on stage I, and 43 (37%) were found to have a nodular, micronodular, or infiltrative component. Significant predictors of reclassified BCC subtype included age over 60 years (P=0.006) and location on the head or neck (P=0.043). Reclassified lesions required significantly more stages of MMS to clear (P=0.036). Shave biopsy was used to diagnose 114 (98%) of the included cases. Over one third of shave biopsies that initially diagnosed sBCC failed to detect a nodular, micronodular, or infiltrative component. Management of biopsy-proven sBCC should take into account the possible presence of an undiagnosed deeper tumor component with appropriate margin-assessment treatment modalities when clinically indicated. J Drugs Dermatol. 2021;20(3):283-288. doi:10.36849/JDD.5383.

Dermoscopy-guided Mohs micrographic surgery in post-laser basal cell carcinomas: is dermoscopy helpful for demarcation of the surgical margin?

Background Mohs micrographic surgery (MMS) in cases where the tumor margin is poorly defined to the naked eye can lead to the need to take an increased number of Mohs stages. Objective To evaluate the usefulness of dermoscopy in determining MMS surgical margins of BCCs with a history of ablative laser treatment. Methods Patients were randomly allocated to naked eye (n = 69) or dermoscopy (n = 64) groups by the surgical margin detection method. Surgical outcomes of 133 post-laser BCC patients treated with MMS were analyzed. Results The lateral margin involvement rate at the first MMS stage was significantly lower in the dermoscopy group than in the naked eye group (4.7% vs. 29.0%; p < .001). However, the deep margin involvement rate at the first and mean MMS stages were not significantly different between the groups. The ablative laser treatment duration correlated to the number of MMS stages (p = .026). Conclusion The results demonstrated that lateral margin was mostly controlled within the first MMS stage with dermoscopy. Dermatosurgeons could focus on the deep margin after the first MMS stage; thus, the performance of MMS could be improved with dermoscopic assistance in post-laser BCC patients.

Hypopigmentation in Extramammary Paget Disease Is an Important Prognostic Factor for High Recurrence Rate and Poor Surgical Outcome.

Several studies have reported the presence of hypopigmentation in extramammary Paget disease (EMPD). However, an in-depth analysis regarding its clinical implication is lacking. To evaluate the clinical characteristics of EMPD in the Korean population and to determine the implication of hypopigmentation on clinical outcomes. We retrospectively reviewed 124 cases of EMPD who underwent surgical treatment from a single tertiary hospital from December 2005 to March 2019. Baseline characteristics of the patients and hypopigmentation patterns were analyzed. Moreover, the number of stages of Mohs micrographic surgery (MMS) and recurrence rate were evaluated in relation to the hypopigmentation. A total of 67.7% (n = 84) of the patients showed hypopigmentation. The adjusted odds ratio for recurrence in the hypopigmented group was 5.980, which was statistically significant (95% confidence interval = 1.347-26.553, p-value = 0.019). Furthermore, the average number of MMS stages was 2.92 in the hypopigmentation group, compared with 1.82 in the nonhypopigmentation group (p-value = .0016). Hypopigmented lesions may disguise the tumor margin, thus raising the recurrence rate after surgery and the number of stages of MMS. The hypopigmentation status must be considered when deciding the surgical margin.

Mohs Micrographic Surgery for Primary Versus Recurrent or Incompletely Excised Facial High-risk Basal Cell Carcinomas.

Facial high-risk basal cell carcinomas are preferably treated with Mohs micrographic surgery, but only 10% of patients are offered Mohs micrographic surgery in Sweden. The aim of this retrospective study was to examine the differences between primary and recurrent or incompletely excised facial high-risk basal cell carcinomas undergoing Mohs micrographic surgery, with regard to the number of stages, final defect sizes, reconstructive techniques and other consequences. The study was performed during the period 2012 to 2019 at our centre. A total of 903 basal cell carcinomas in 813 patients (70.1% primary, 10.4% incompletely excised and 19.5% recurrences) were included. The mean number of Mohs micrographic surgery stages was significantly lower for primary basal cell carcinomas compared with recurrences (p = 0.03), and the mean final defect size was significantly smaller in primary basal cell carcinomas compared with both recurrent (p < 0.0001) and incompletely excised (p = 0.003) tumours. Primary basal cell carcinomas tended to more often be reconstructed by primary closure (p = 0.08). Mohs micrographic surgery indications for facial high-risk basal cell carcinomas should be respected and used more frequently on primary basal cell carcinomas, in order to enable better utilization of resources and improved outcomes for the patient.