Nonmelanoma Skin Cancer in Patients Older Than Age 85 Years Presenting for Mohs Surgery: A Prospective, Multicenter Cohort Study.

Importance: It has been suggested that Mohs surgery for skin cancer among individuals with limited life expectancy may be associated with needless risk and discomfort, along with increased health care costs. Objective: To investigate patient- and tumor-specific indications considered by clinicians for treatment of nonmelanoma skin cancer in older individuals. Design, Setting, and Participants: This multicenter, prospective cohort study was conducted using data from US private practice and academic centers. Included patients were those older than age 85 years presenting for skin cancer surgery and referred for Mohs surgery, with reference groups of those younger than age 85 years receiving Mohs surgery and those older than age 85 years not receiving Mohs surgery. Data were analyzed from November 2018 through January 2019. Exposures: Mohs surgery for nonmelanoma skin cancer. Main Outcomes and Measures: Reason for treatment selection. Results: Among 1181 patients older than age 85 years referred for Mohs surgery (724 [61.9%] men among 1169 patients with sex data; 681 individuals aged >85 to 88 years [57.9%] among 1176 patients with age data) treated at 22 sites, 1078 patients (91.3%) were treated by Mohs surgery, and 103 patients (8.7%) received alternate treatment. Patients receiving Mohs surgery were more likely to have tumors on the face (738 patients [68.5%] vs 26 patients [25.2%]; P < .001) and nearly 4-fold more likely to have high functional status (614 patients [57.0%] vs 16 patients [15.5%]; P < .001). Of 15 distinct reasons provided by surgeons for opting to proceed with Mohs surgery, the most common were patient desire for treatment with a high cure rate (712 patients [66.0%]), good or excellent patient functional status for age (614 patients [57.0%]), and high risk associated with the tumor based on histology (433 patients [40.2%]). Conclusions and Relevance: This study found that older patients who received Mohs surgery often had high functional status, high-risk tumors, and tumors located on the face. These findings suggest that timely surgical treatment may be appropriate in older patients given that their tumors may be aggressive, painful, disfiguring, and anxiety provoking.

Natural History of Incident and Persistent Cutaneous Human Papillomavirus and Human Polyomavirus Infections.

BACKGROUND: Cutaneous human papillomaviruses (cuHPV) and polyomaviruses (HPyV) have been implicated in skin cancers; however, interpretation of findings across studies is complicated by limited understanding of the natural history of these infections across normal tissue types. METHODS: In total, 675 eyebrow hair (EBH) and skin swab (SSW) samples were collected from 71 skin cancer screening patients every 6 months over 2 years and measured for presence of ß-HPV, γ-HPV, and HPyV. Incidence, persistence, and clearance of cuHPV/HPyV were estimated, and risk factors associated with infection were examined. RESULTS: Prevalence, incidence, and persistence of ß-HPV, γ-HPV, and HPyV were consistently higher in SSW than in EBH, with types 5, 24, 49, 76 and Merkel cell polyomavirus (MCPyV) having incidence rates greater than 20 per 1000 person-months. Prevalent γ-HPV EBH infections persisted more often in women (P = .024), incident ß-HPV EBH infections persisted less often among individuals with history of blistering sunburn (P = .019), and prevalent MCPyV SSW infections persisted more often in those with a history of skin cancer (P = .033). CONCLUSIONS: Incidence and persistence of cuHPV/HPyV were observed in SSW and EBH; however, none of the risk factors examined were commonly associated with cuHPV/HPyV infections across normal tissue types.

Circulating Immunosuppressive Regulatory T Cells Predict Risk of Incident Cutaneous Squamous Cell Carcinoma.

Ultraviolet radiation exposure (UVR) is a risk factor for cutaneous squamous cell carcinoma (cuSCC) and has been shown to be positively associated with circulating immunosuppressive regulatory T cells ("Tregs"). However, the risk of cuSCC in association with circulating Tregs has not been studied. The aim of this study was to determine whether circulating Treg levels are associated with cuSCC development, particularly in the context of high UVR. Blood and spectrophotometer-based UVR measurements were obtained on 327 immunocompetent individuals undergoing routine skin cancer screenings at baseline and followed for up to 4 years for incident cuSCC development within a prospective cohort study. Proportions of phenotypically distinct Tregs, especially CCR4hi and CLA+ cells which are associated with activation and homing, respectively, were measured by flow cytometry. Tregs in cuSCC tumors were assessed using immunohistochemistry and graded for solar elastosis, a measure of cumulative UVR damage. Of several Treg phenotypes examined, higher levels of circulating CCR4hi Tregs at baseline were significantly associated with increased risk of subsequent cuSCC; those with higher levels of both CCR4hi and UVR were four times more likely to develop cuSCC compared to those with lower levels of both (Hazard Ratio = 4.11, 95% CI = 1.22-13.90). Within cuSCC tumors, CCR4hi Tregs were positively associated with solar elastosis. Results show that a higher proportion of CCR4hi peripheral Tregs predicts incident cuSCC up to 4 years, especially among highly UV-exposed individuals. Research of the underpinning biology of Tregs in UVR-associated skin damage may possibly reveal novel opportunities for screening, prevention, and treatment.

Cutaneous Human Papillomaviruses and the Risk of Keratinocyte Carcinomas.

Cutaneous human papillomavirus (cuHPV) infections may be novel targets for skin cancer prevention and treatment, but critical information regarding the development of virus-positive skin cancers following cuHPV infection has been lacking. In this study, baseline cuHPV infection was measured by serology and viral DNA detection in eyebrow hairs (EBH) and forearm skin swabs (SSW) among 1,008 individuals undergoing routine skin cancer screening exams and followed for incidence of basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cuSCC). Baseline ß-HPV detection, particularly in SSW, significantly predicted cuSCC (HR = 4.32; 95% confidence interval, 1.00-18.66), whereas serologic evidence of past ß-HPV infection was not associated with cuSCC. Less than 5% of baseline ß-HPV types detected in SSW were present in subsequent cuSCC tumors, and cuHPV detected in SSW with higher mean fluorescence intensity values were more likely to be present in cuSCC compared with those with lower levels (P < 0.001). ß-HPV-positive cuSCC occurred more often in areas of highly sun-damaged skin than did ß-HPV-negative cuSCC. Overall, no clear patterns were observed between baseline ß-HPV detection and subsequent development of BCC, or between baseline γ-HPV detection and either cuSCC or BCC. Collectively, these results demonstrate that ß-HPV detection in SSW is a significant predictor of cuSCC risk, although evidence suggests only a small subset of cuSCC is etiologically linked to ß-HPV infection. SIGNIFICANCE: ß-HPV positivity may be a useful biomarker for identifying individuals who could benefit from increased screening or novel cutaneous squamous cell carcinoma prevention strategies.

Association between Human Polyomaviruses and Keratinocyte Carcinomas: A Prospective Cohort Study.

BACKGROUND: A positive association between Merkel cell polyomavirus (MCPyV) infection and cutaneous squamous cell carcinoma (cuSCC) has been observed in at least one previous case-control study. To evaluate this association in a prospective context, we investigated infections with human polyomaviruses (HPyV), including MCPyV, as predictors of keratinocyte carcinomas, including cuSCC and basal cell carcinoma (BCC), among a cohort of immunocompetent individuals enrolled in the Viruses in Skin Cancer (VIRUSCAN) Study. METHODS: Associations between markers of baseline HPyV infection (serum antibodies and viral DNA in eyebrow hairs and skin swabs) and incident keratinocyte carcinomas were modeled using Cox proportional hazards regression. Proportions of baseline HPyV infections that were concordant with a subsequent tumor positive for the same HPyV type were assessed. RESULTS: No significant associations were observed between baseline markers of MCPyV or other HPyV infections and cuSCC or BCC. Less than 4.5% of baseline MCPyV infections were also detected in subsequently developed keratinocyte carcinoma tumors. CONCLUSIONS: HPyV infection was not a predictor of keratinocyte carcinoma risk in this prospective cohort. IMPACT: Cancer-associated infections represent attractive targets for cancer prevention; however, HPyV infections have limited potential as novel targets for cuSCC prevention.

Viruses in Skin Cancer (VIRUSCAN): Study Design and Baseline Characteristics of a Prospective Clinic-Based Cohort Study.

BACKGROUND: Accumulating evidence suggests that cutaneous viral infections are risk factors for the development of keratinocyte carcinomas. The Viruses in Skin Cancer (VIRUSCAN) Study, a prospective cohort study, was established in 2014 to investigate the risk of keratinocyte carcinoma associated with cutaneous human papillomavirus and polyomavirus infection and the possible interaction with ultraviolet radiation exposure (UVR). METHODS/RESULTS: VIRUSCAN incorporates repeated measures of viral infection using multiple markers of infection and quantitative measures of UVR using a spectrophotometer. Participants were recruited between July 14, 2014 and August 31, 2017 at the University of South Florida Dermatology Clinic in Tampa, FL. After excluding 124 individuals with prevalent keratinocyte carcinomas at baseline, 1,179 participants (53.2% women, 46.8% men, all ages 60 years and older) were followed for up to 4 years with routine skin exams occurring every 6 to 12 months. Here, we present the VIRUSCAN Study design, methods, and baseline characteristics, including demographics, sun exposure behavior, quantitative UVR exposure measurements, and cutaneous viral prevalence, for the full study cohort. CONCLUSIONS: The VIRUSCAN Study will provide critical temporal evidence needed to assess the causality of the role cutaneous viral infections play in the development of keratinocyte carcinomas, as well as the potential interaction between cutaneous viral infections and UVR exposure. IMPACT: Study findings will be valuable in future development of novel keratinocyte carcinoma prevention strategies.

Case-control study of genus-beta human papillomaviruses in plucked eyebrow hairs and cutaneous squamous cell carcinoma.

Cutaneous human papillomaviruses (HPV) have been reported in cutaneous squamous cell carcinoma (SCC). We conducted a clinic-based case-control study to investigate the association between genus-beta HPV DNA in eyebrow hairs (EBH) and SCC. EBH from 168 SCC cases and 290 controls were genotyped for genus-beta HPV DNA. SCC tumors from a subset of cases (n = 142) were also genotyped. Viral load was determined in a subset of specimens positive for a single HPV type. Associations with SCC were estimated by odds ratios (OR) and 95% confidence intervals (CI) adjusted for age and sex using logistic regression. Statistical tests were two-sided. EBH DNA prevalence was greater in cases (87%) than controls (73%) (p < 0.05), and the association with SCC increased with the number of HPV types present, (≥ 4 types vs. HPV-negative: OR = 2.02, 95% CI = 1.07-3.80; p(trend) = 0.02). Type-specific associations were observed between SCC and DNA in EBH for HPV23 (OR = 1.90, 95% CI = 1.10-3.30) and HPV38 (OR = 1.84, 95% CI = 1.04-3.24). Additionally, when compared with the controls, the DNA prevalence in EBH was significantly higher among cases for 11 of the 25 genus-beta types tested, when accounting for DNA for the same HPV type in the tumor (ORs = 3.44-76.50). Compared to controls, the mean viral DNA load in EBH among the selected cases was greater for HPV5, HPV8 and HPV24, but lower for HPV38. SCC cases were more likely than controls to have HPV DNA+ EBH for single and multiple HPV types, providing additional support for the potential role of genus-beta HPV infections in SCC development.

Telomere length and risk of melanoma, squamous cell carcinoma, and basal cell carcinoma.

BACKGROUND: Telomeres help maintain chromosomal structure and may influence tumorigenesis. We examined the association between telomere length and skin cancer in a clinic-based case-control study of 198 melanoma cases, 136 squamous cell carcinoma (SCC) cases, 185 basal cell carcinoma (BCC) cases, and 372 healthy controls. METHODS: Cases were histologically confirmed patients treated at the Moffitt Cancer Center and University of South Florida Dermatology Clinic in Tampa, FL. Controls self-reported no history of cancer and underwent a skin cancer screening exam at study enrollment to rule out the presence of skin cancer. Quantitative real time PCR was used to measure telomere length in peripheral blood samples. RESULTS: Melanoma patients had longer telomeres than controls (odds ratio (OR)=3.75; 95% confidence interval (CI): 2.02-6.94 for highest versus lowest tertile) (P for trend=<0.0001). In contrast, longer telomere length was significantly inversely associated with SCC (OR=0.01; 95% CI: 0.00-0.05 for highest versus lowest tertile) (P for trend=<0.0001) and BCC (OR=0.10; 95% CI: 0.06-0.19 for highest versus lowest tertile) (P for trend=<0.0001). CONCLUSION: Telomere length may be involved in the development of skin cancer, although the effect on cancer risk differs for melanoma and non-melanoma carcinomas. Our findings suggest that long telomere length is positively associated with melanoma while inversely associated with SCC and BCC.

Case-control study of cutaneous human papillomavirus infection in Basal cell carcinoma of the skin.

Genus-ß human papillomavirus (HPV) DNA has been detected in basal cell carcinoma (BCC) tumors, but most epidemiologic studies have not observed associations between genus-ß HPV seropositivity and BCC. A clinic-based case-control study was conducted to investigate cutaneous HPV infection in BCC. BCC cases (n=224) were recruited from a dermatology clinic, and controls (n=300) were patients who were screened negative for skin cancer. Antibodies against cutaneous HPV types in genera α, ß, γ, mu, and nu were measured, and tumors from a subset of BCC cases (n=195) were tested for HPV DNA. Overall associations were observed between BCC and seropositivity for HPV types in genus-α (odds ratio (OR)=1.61; 95% confidence interval (CI)=1.11-2.35), γ (OR=1.78; 95% CI=1.22-2.60), and mu (OR=1.56; 95% CI=1.06-2.30). BCC cases with ß-HPV DNA in their tumors were more likely to be ß-HPV seropositive than controls (OR=1.76; 95% CI=1.03-3.01), with type-specific associations observed for HPV8 and HPV23, whereas no association was observed between ß-HPV seropositivity and ß-HPV DNA-negative BCC. No concordance between seropositivity and tumor DNA status was observed for HPV types in genera α and γ. In conclusion, the combined serology and tumor DNA results suggest that ß HPV types may have a role in BCC. Additional studies of BCC that assess HPV types in multiple genera are needed.

Rapid immunostaining in Mohs: current applications and attitudes.

BACKGROUND: Rapid immunostaining in Mohs micrographic surgery (MMS) has been extensively reviewed in the recent literature. Despite the recent attention, there is relatively little information on how frequently these techniques are actually utilized and the current attitudes of the Mohs community towards immunohistochemical (IHC) stains. OBJECTIVE: We attempted to obtain information on the utilization and attitudes towards the use of rapid immunostaining in Mohs through a survey of fellowship-trained Mohs surgeons. MATERIALS AND METHODS: A twenty-five question survey was sent to members of the American College of Mohs Surgery (ACMS) through various methods including SurveyMonkey(®) , email, fax, and Metrofax(®) . RESULTS: A total of 378 surveys were completed. These responses represent a cross-section of fellowship-trained members of the ACMS. CONCLUSIONS: The vast majority of respondents felt as though IHC stains could be used reliably in Mohs. A subset of responses indicated that the most common reasons for not using IHC stains are time consumption, lack of education, and startup and/or maintenance costs. An increase in immunostain usage over 10 years ago appears to correlate with the activity in the literature. There may be an underutilization of IHC staining in fellowship programs, as indicated by respondents' opinions.

Patterns and timing of sunlight exposure and risk of basal cell and squamous cell carcinomas of the skin--a case-control study.

BACKGROUND: Non-melanoma skin cancer (NMSC), comprised of basal (BCC) and squamous (SCC) cell carcinomas, is the most common cancer in Caucasians. Ultraviolet radiation (UVR) exposure is the most important environmental risk factor for NMSC. However, the precise relationship between UVR and the risk of NMSC is complex, and the relationship may differ by skin cancer type. METHODS: A case-control study was conducted among Florida residents to investigate measures of patterns (intermittent vs. continuous) and timing (childhood vs. adulthood) of sunlight exposure in BCC and SCC. Participants included 218 BCC and 169 SCC cases recruited from a university dermatology clinic and 316 controls with no history of skin or other cancers. RESULTS: A history of blistering sunburn (a measure of intermittent sunlight exposure) was associated with both BCC (OR = 1.96, 95% CI = 1.27-3.03) and SCC (OR = 2.02, 95% CI = 1.22-3.33). Additionally, having a job in the sun for ≥ 3 months for 10 years or longer (a measure of continuous sunlight exposure) was also associated with both BCC and SCC in our study population. With the exception of younger age at first blistering sunburn, measures of younger age at sunlight exposure tended to be associated with SCC, but not BCC risk. CONCLUSIONS: Results from the current study suggest that sunlight exposure is associated with both BCC and SCC risk regardless of the pattern in which the exposure was received (i.e. intermittent vs. continuous). The data also suggest that sunlight exposure at a younger age may be more important for SCC but not BCC, however additional studies are needed to further characterize sunlight exposure-response relationships in different types of NMSC.

Sunlight exposure and cutaneous human papillomavirus seroreactivity in basal cell and squamous cell carcinomas of the skin.

BACKGROUND: Ultraviolet radiation exposure may interact synergistically with cutaneous human papillomavirus (HPV) infection in the development of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) of the skin. METHODS: To investigate differences in the risk of sunlight-associated BCC and SCC by cutaneous genus-specific HPV serostatus, a case-control study was conducted among 204 BCC and 156 SCC cases who were recruited from a university dermatology clinic and 297 controls who had no history of cancer and screened negative for current skin cancer. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for the associations between measures of sunlight exposure and BCC/SCC, stratified by genus-specific HPV serostatus, with adjustment for age and sex. RESULTS: Sunburn due to cutaneous sensitivity to sunlight exposure (P = .006) and poor tanning ability (P = .003) were associated with a higher seroprevalence for genus beta HPV types. Poor or no tanning ability was more strongly associated with SCC among individuals who were seropositive for antibodies to cutaneous HPV types in genera alpha (OR, 15.60; 95% CI, 5.40-45.1; P = .01 for interaction) and beta (OR, 6.86; 95% CI, 3.68-12.80; P = .001 for interaction), compared with individuals who were seronegative for these HPV types. CONCLUSIONS: Seropositivity for HPV types in genera alpha or beta increased the risk of SCC associated with poor tanning ability.

Case-control study of cutaneous human papillomaviruses in squamous cell carcinoma of the skin.

BACKGROUND: Cutaneous human papillomavirus (HPV) infection may be a risk factor for squamous cell carcinoma (SCC) of the skin. METHODS: To investigate the association between cutaneous HPV and SCC, a case-control study was conducted, including 173 SCC cases from a university dermatology clinic and 300 controls that screened negative for skin cancer. Serum antibodies against cutaneous HPV types in genera alpha, beta, gamma, mu, and nu were measured. Tumor tissue from 159 SCC cases was tested for the presence of DNA for genus-beta HPV types. Using logistic regression ORs and 95% confidence intervals (CI) were estimated for the associations between SCC and cutaneous HPV infection, adjusting for age and sex. The Bonferroni method was used to account for multiple comparisons. RESULTS: SCC was positively associated with seropositivity to any genus-beta HPV type (OR, 1.93; 95% CI, 1.23-3.02), particularly with types in species-1 (OR, 1.86; 95% CI, 1.22-2.85). Type-specific associations with SCC were observed for HPV 8 (OR, 1.80; 95% CI, 1.14-2.84), 17 (OR, 1.59; 95% CI, 1.02-2.49) and HPV 10 from genus-alpha (OR, 2.24; 95% CI, 1.04-4.85). None of the type-specific associations remained statistically significant after correction for multiple comparisons. When DNA-positive SCC cases were compared with controls, strong serologic associations were observed for HPVs 5 (OR, 3.48; 95% CI, 1.27-9.59), 17 (OR, 3.36; 95% CI, 1.29-8.72), and 24 (OR, 3.79; 95% CI, 1.24-11.5). CONCLUSION: Genus-beta HPV infections were associated with SCC in our study population. IMPACT: Identifying the role of cutaneous HPV infection in SCC may lead to improved characterization of high-risk individuals and the development of novel prevention strategies.

Advances in the management of cutaneous toxicities of targeted therapies.

Contrary to what might have been expected, the effects of targeted therapies are not limited to the cancer cells and are unfortunately associated with many and numerous adverse events. Dermatologic manifestations are among the most frequently observed, and, when severe and/or protracted, they inevitably impact the quality of life of patients. Management of these various side effects is empirical and mostly based on expert advice and consensus. We will review the skin side effects of EGFR, VEGFR, KIT, platelet-derived growth factor receptor (PDGFR), and BCR-ABL inhibitors, as well as mTOR inhibitors.

Case-control study of smoking and non-melanoma skin cancer.

OBJECTIVE: To investigate the association between cigarette smoking and basal and squamous cell carcinomas (BCC and SCC) of the skin, a clinic-based case-control study was conducted in Tampa, FL. METHODS: Patients with histologically confirmed BCC/SCC were recruited from a university dermatology clinic (n = 215 BCC, 165 SCC). Controls were comprised of individuals with no history of skin cancer who screened negative for skin cancer upon physical examination at the affiliated cancer screening or primary care clinics (n = 315). Information on smoking and other risk factors was obtained from self-administered questionnaires. RESULTS: After adjustment for age, sex, and other skin cancer-risk factors, ever smoking was not associated with BCC (odds ratio (OR) = 1.26, 95% confidence interval (CI) = 0.83-1.92), but was statistically significantly associated with SCC (OR = 1.97, 95% CI = 1.19-3.26), with significant trends observed for SCC associated with increasing cigarettes per day (p = 0.01) and pack-years smoked (p = 0.01). Among men, smoking ≥20 pack-years was associated with non-significant increased risks of BCC (OR = 1.90, 95% CI = 0.88-4.12) and SCC (OR = 1.97, 95% CI = 0.84-4.66), whereas among women, no association was observed with BCC (OR = 0.98, 95% CI = 0.39-2.46) while a statistically significant three-fold risk was observed with SCC (OR = 3.00, 95% CI = 1.02-8.80). CONCLUSION: Cigarette smoking is more strongly associated with SCC than BCC, particularly among women.

Case-control study of Merkel cell polyomavirus infection and cutaneous squamous cell carcinoma.

BACKGROUND: Merkel cell polyomavirus (MCV) DNA has been reported in 0% to 25% of squamous cell carcinomas (SCC) occurring in immunocompetent individuals. We conducted the first serologic case-control study of MCV and SCC. METHODS: Patients with histologically confirmed cutaneous SCC (n = 173) were recruited from a university dermatology clinic. Controls were individuals who screened negative for and had no history of skin or other cancers (n = 300). Levels of antibodies against capsid antigens for MCV and another polyomavirus, JC virus (JCV), were determined by fluorescent bead-based multiplex serology. Fresh-frozen tumor tissues were obtained from 145 SCC cases and tested for MCV DNA by multiplexed PCR. Associations between MCV seroreactivity and SCC were estimated by ORs and 95% CIs calculated using logistic regression with adjustment for age and sex. RESULTS: MCV DNA was detected in SCC tumor tissues from 55 (38%) of 145 cases. A statistically significant association was observed between MCV seropositivity and MCV DNA-positive SCC (OR = 2.49, 95% CI = 1.03-6.04), with an almost four-fold association observed when comparing those with MCV antibodies in the fourth versus first quartiles (OR = 3.93, 95% CI = 1.43-10.76, P(trend) = 0.01). No significant associations were observed between MCV seropositivity and MCV DNA-negative SCC (OR = 1.38, 95% CI = 0.76-2.48) or between JCV seropositivity and MCV DNA-positive or DNA-negative SCC. CONCLUSION: Past exposure to MCV may be a risk factor for SCC. IMPACT: Understanding the role of viral infections in the development of nonmelanoma skin cancer could lead to novel prevention strategies.

Mohs surgery for melanoma: rationale, advances and possibilities.

Mohs surgery (MS) is an effective technique for the removal of a variety of cutaneous neoplasms by virtue of its thorough assessment of margins. It has yet to become widely accepted for melanoma because recognizing melanocytes histologically in frozen section can be problematic. Recently, 'rapid' methods of immunohistochemistry have been developed that resolve this issue by staining the melanocytes in frozen section. In addition, some of the immunohistochemistry protocols that previously required up to 1 h now take 19 min or less. These technological enhancements for MS have removed some of the obstacles towards the acceptance of MS as a legitimate option for removal of melanomas, especially poorly demarcated lesions and lesions from the head and neck, the distal extremities and the genitalia. Experience thus far with MS for melanoma has shown lower recurrence rates and improved disease-specific survival compared with historical controls for standard excision, while at the same time minimizing the sacrifice of normal tissue.

Distinction of melanoma in situ from solar lentigo on sun-damaged skin using morphometrics and MITF immunohistochemistry.

Distinction between melanoma in situ (MIS) and solar lentigo (SL) on chronically sun-damaged skin (CSDS) by hematoxylin and eosin (H&E) criteria alone can be difficult and in frozen section (FS) material, may be virtually impossible without immunohistochemistry (IHC). In this study, we used microphthalmia-associated transcription factor (MITF) IHC-directed image analysis to compare melanocyte nuclear morphometrics of MIS, SL, and sections of sun-damaged skin from redundant tissue acquired during Mohs micrographic surgery. The mean nuclear diameter and melanocytic density figures for MIS were greater than those for SL and CSDS by both independent t-test and analysis of variance statistics. No significant differences in these parameters were found between SL and sun-damaged skin. Cutoff values that favored MIS over SL included melanocyte density ≥10 nuclei per 200 µm, nuclear diameter ≥9 µm, and a product of density and diameter of 80 or more, as each of these values was associated with 100% specificity of MIS diagnosis. Our results suggest that image analysis of melanocytes labeled with MITF IHC can be used to produce morphometric data that distinguish MIS from SL and CSDS. The study was conducted using permanent sections, but previous studies with FSs indicate that the findings would apply to FSs as well. Quantitative assessment of melanocytic parameters using image analysis will likely become increasingly important as an adjunct to conventional histopathology for the diagnosis and surgical management of MIS on sun-damaged skin.