NCCN Guidelines® Insights: Merkel Cell Carcinoma, Version 1.2024.

The NCCN Guidelines for Merkel Cell Carcinoma (MCC) provide recommendations for diagnostic workup, clinical stage, and treatment options for patients. The panel meets annually to discuss updates to the guidelines based on comments from expert review from panel members, institutional review, as well as submissions from within NCCN and external organizations. These NCCN Guidelines Insights focus on the introduction of a new page for locally advanced disease in the setting of clinical node negative status, entitled "Clinical N0 Disease, Locally Advanced MCC." This new algorithm page addresses locally advanced disease, and the panel clarifies the meaning behind the term "nonsurgical" by further defining locally advanced disease. In addition, the guideline includes the management of in-transit disease and updates to the systemic therapy options.

Multiple primary dermatofibrosarcoma protuberans tumors in a single patient with chromosomal microarray analysis: A case report and review.

Dermatofibrosarcoma protuberans (DFSP) is a cutaneous sarcoma with a high propensity for local invasion and recurrence. Although it is a rare event, the occurrence of multiple tumors in a single patient raises a diagnostic dilemma, as metastatic disease should be differentiated from multiple primary malignant events. In more than 90% of DFSP, a pathogenic t(17;22) translocation leads to the expression of COL1A1::PDGFB fusion transcripts. Karyotype analysis, fluorescence in situ hybridization, and RT-PCR can be useful ancillary studies in detecting this characteristic rearrangement, and sequencing of the fusion transcript can be used to support a clonal origin in metastatic and multifocal disease. However, previous reports have demonstrated variable sensitivity of these assays, in part due to the high sequence variability of the COL1A1::PDGFB fusion. Here, we report a patient who developed two distinct DFSP tumors over the course of 7 years. Chromosomal microarray analysis identified distinctive genomic alterations in the two tumors, supporting the occurrence of multiple primary malignant events.

The relationship between acrochordons, obesity, and metabolic syndrome in the pediatric population: A retrospective cohort study.

BACKGROUND: Acrochordons or skin tags are common benign skin growths. Several studies explored the relationship between obesity and metabolic syndrome in adults but remains unexplored in children. METHODS: This was a single-center retrospective cohort study of outpatient dermatology patients between 1 January 2000 to 1 January 2021. Children under 18 years old diagnosed with acrochordons using diagnostic codes International Classification of Diseases, 10th Revision (ICD-10) L91.8 and 9th Revision (ICD-9) 701.8 were included. We collected patient demographics, past medical history, laboratory values, vital signs, and physical exam. Body mass index (BMI) was calculated and stratified into categories based on the Center for Disease Control's BMI-for-Age Growth Charts. Metabolic syndrome was diagnosed when three of the five criteria were met. Data were propensity-matched and compared with NHANES (National Health and Nutrition Examination Survey), which offered a generalizable sample to the US population. RESULTS: Fifty-five patients under 18 years old with a diagnosis of acrochordons were mostly Caucasian (76%) and female (64%). The mean BMI was 27.3, with 49.5% categorized as obese and 20% as overweight. The mean age of diagnosis was 10.1 years. Acrochordon predominantly appeared in the axilla. In our cohort, three patients (5.5%) met the criteria for metabolic syndrome. The prevalence of obesity (42% vs. 21%), type 2 diabetes mellitus (4.8% vs. 0.6%), hyperlipidemia (8.1% vs. 0%), and hypertension (1.6% vs. 0%) was greater in our cohort compared with NHANES. CONCLUSIONS: Like the adult population, acrochordons may serve as marker for metabolic disease in the pediatric population.

Basal Cell Skin Cancer, Version 2.2024, NCCN Clinical Practice Guidelines in Oncology.

Basal cell carcinoma (BCC) is the most common form of skin cancer in the United States. Due to the high frequency, BCC occurrences are not typically recorded, and annual rates of incidence can only be estimated. Current estimated rates are 2 million Americans affected annually, and this continues to rise. Exposure to radiation, from either sunlight or previous medical therapy, is a key player in BCC development. BCC is not as aggressive as other skin cancers because it is less likely to metastasize. However, surgery and radiation are prevalent treatment options, therefore disfigurement and limitation of function are significant considerations. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) outline an updated risk stratification and treatment options available for BCC.

Development of a core outcome set for basal cell carcinoma.

BACKGROUND: There is variation in the outcomes reported in clinical studies of basal cell carcinoma. This can prevent effective meta-analyses from answering important clinical questions. OBJECTIVE: To identify a recommended minimum set of core outcomes for basal cell carcinoma clinical trials. METHODS: Patient and professional Delphi process to cull a long list, culminating in a consensus meeting. To be provisionally accepted, outcomes needed to be deemed important (score, 7-9, with 9 being the maximum) by 70% of each stakeholder group. RESULTS: Two hundred thirty-five candidate outcomes identified via a systematic literature review and survey of key stakeholders were reduced to 74 that were rated by 100 health care professionals and patients in 2 Delphi rounds. Twenty-seven outcomes were provisionally accepted. The final core set of 5 agreed-upon outcomes after the consensus meeting included complete response; persistent or serious adverse events; recurrence-free survival; quality of life; and patient satisfaction, including cosmetic outcome. LIMITATIONS: English-speaking patients and professionals rated outcomes extracted from English language studies. CONCLUSION: A core outcome set for basal cell carcinoma has been developed. The use of relevant measures may improve the utility of clinical research and the quality of therapeutic guidance available to clinicians.

NCCN Guidelines® Insights: Squamous Cell Skin Cancer, Version 1.2022.

The NCCN Guidelines for Squamous Cell Skin Cancer provide recommendations for diagnostic workup, clinical stage, and treatment options for patients with cutaneous squamous cell carcinoma. The NCCN panel meets annually to discuss updates to the guidelines based on comments from panel members and the Institutional Review, as well as submissions from within NCCN and external organizations. These NCCN Guidelines Insights focus on the introduction of a new surgical recommendation terminology (peripheral and deep en face margin assessment), as well as recent updates on topical prophylaxis, immunotherapy for regional and metastatic disease, and radiation therapy.

Dermatology residency preparation curriculum: a model for initiating new residents into dermatology clinical care.

Entering dermatology residency is an immersive experience requiring new specialty-specific skills. There is no standard Accreditation Council for Graduate Medical Education (ACGME) protocol for orienting new dermatology residents. We aimed to design, develop, and evaluate a curriculum for incoming first-year dermatology residents focusing on practical introduction to dermatologic clinical care emphasizing ACGME dermatology milestones. A concentrated 8-hour residency preparation course for first-year dermatology residents was designed and developed by faculty. The course encompassed clinical competencies, procedural techniques, and professionalism and collegiality principles. Teaching methods included lectures, video demonstrations, simulated patient experiences, and one-on-one practical instruction. Surveys were distributed before, immediately after, and 6-months following the course from 2016-2018 to assess participants' skill-based confidence level and perceived usefulness of the course. A total of 24 first-year dermatology residents participated in the residency preparation course over 3 years from 2016-2018. Residents' confidence levels in performing dermatology-specific skills immediately increased following the course and continued to increase 6 months into training. The majority of first-year residents "agreed" or "strongly agreed" that the course was helpful for improving clinical competence. Our residency preparation course increased first-year residents' confidence and perceived competence in performing clinical skills related to ACGME dermatology milestones.

Completion Lymph Node Dissection or Radiation Therapy for Sentinel Node Metastasis in Merkel Cell Carcinoma.

BACKGROUND: For sentinel lymph node (SLN) metastasis from Merkel cell carcinoma (MCC), the benefit of completion lymph node dissection (CLND) versus radiation therapy (RT) is unclear. This study compares outcomes for patients with SLN metastasis undergoing CLND or RT. We also evaluated positive non-SLNs as a prognostic factor. METHODS: Using a prospective database, we identified MCC patients with SLN metastasis who underwent CLND or RT. At our institution, CLND was recommended for patients with acceptable perioperative risk, while therapeutic RT was offered to those with high perioperative risk. Primary outcomes were MCC-specific survival (MCCSS), disease-free survival (DFS), nodal recurrence-free survival (NRFS), and distant recurrence-free survival (DRFS). RESULTS: From 2006 to 2017, 163 patients underwent CLND (n = 137) or RT (n = 26). Median follow-up was 1.9 years. CLND had no significant differences for MCCSS (5-year survival 71% vs. 64%, p = 1.0), DFS (52% vs. 61%, p = 0.8), NRFS (76% vs. 91%, p = 0.3), or DRFS (65% vs. 75%, p = 0.3) compared with RT. Patients with positive non-SLNs (n = 44) had significantly worse MCCSS (5-year survival 39% vs. 87%, p < 0.001), DFS (35% vs. 60%, p = 0.005), and DRFS (54% vs. 71%, p = 0.03) compared with negative non-SLNs (n = 93). Multivariate analysis showed positive non-SLNs were independently associated with MCCSS, DFS, and DRFS. CONCLUSIONS: CLND and RT may have similar outcomes for MCC patients with SLN metastasis when treatment aligns with our institutional practices. For patients undergoing CLND, positive non-SLNs is an important prognostic factor associated with poor survival and distant recurrence. This high-risk group should be considered for adjuvant systemic therapy trials.

Neurofilament is superior to cytokeratin 20 in supporting cutaneous origin for neuroendocrine carcinoma.

AIM: Primary cutaneous neuroendocrine carcinoma, or Merkel cell carcinoma (MCC), cannot be distinguished morphologically from small-cell neuroendocrine carcinomas (SmCC) from other sites. Immunohistochemistry is required to confirm cutaneous origin, and is also used for detection of sentinel lymph node (SLN) metastases of MCC. Cytokeratin 20 (CK20) expression is commonly used for these purposes, but is negative in some MCC cases, and has unclear specificity. We evaluated immunohistochemistry for neurofilament and CK20 in MCC compared with SmCC from other sites. METHODS AND RESULTS: We evaluated neurofilament expression in 55 MCC specimens from 39 unique patients, including nine CK20-negative MCC tumours. Neurofilament expression was observed in 42 of 55 (76.4%) MCC cases, including seven of nine (77.8%) CK20-negative MCC cases. Neurofilament was expressed in nine of 12 (75%) Merkel cell polyomavirus-positive tumours and five of 10 (50%) virus-negative tumours. Compared to a standard immunohistochemical panel (cytokeratin cocktail and CK20), neurofilament was 87.5% sensitive for detecting SLN metastases. Neurofilament and CK20 expression was also assessed in 61 extracutaneous SmCC from 60 unique patients, with primary sites including lung (27), bladder (18), cervix (3), gastrointestinal tract (3), sinonasal tract (2) and other sites (7). The specificity of neurofilament and CK20 for MCC versus non-cutaneous SmCC was 96.7% and 59.0%, respectively. CONCLUSIONS: Neurofilament has superior specificity to CK20 in distinguishing MCC from non-cutaneous SmCC. Neurofilament is frequently expressed in CK20- and virus-negative MCC tumours. Limitations of neurofilament immunohistochemistry include lower sensitivity than CK20 and subtle staining in some tumours. However, our findings indicate that neurofilament is useful for excluding non-cutaneous SmCC.

Merkel cell carcinoma arising in association with cutaneous T-cell lymphoma: A potential diagnostic pitfall.

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous neuroendocrine carcinoma with increased prevalence in patients with immunosuppression or B-cell neoplasms. To the best of our knowledge, an association with cutaneous T-cell lymphoma (CTCL) has not been previously described. In this report, we present two cases of MCC arising in the setting of CTCL. The first case was a female during her 70s with previously diagnosed stage IVA1 Sezary syndrome. Biopsy of a scaly patch showed two distinct abnormal cell populations. The first population consisted of hyperchromatic dermal and epidermotropic lymphocytes, expressing CD3 and CD4 with diminished CD7. The second population consisted of intraepidermal clusters of larger atypical cells that expressed synaptophysin, neurofilament, CK20, and Merkel cell polyomavirus transcript. The combination of findings was consistent with intraepidermal MCC in a background of CTCL. Excision showed residual intraepidermal MCC without dermal involvement. The second case was a male during his 50s with a longstanding history of mycosis fungoides, who presented with a new lesion on his right thigh. Biopsy and excision showed dermal MCC without secondary involvement by CTCL. Our cases show that MCC may rarely occur in the setting of T-cell lymphoma, and that intraepidermal MCC may mimic epidermotropic T-cells.

Merkel cell carcinoma: Current US incidence and projected increases based on changing demographics.

BACKGROUND: Merkel cell carcinoma (MCC) incidence rates are rising and strongly age-associated, relevant for an aging population. OBJECTIVE: Determine MCC incidence in the United States and project incident cases through the year 2025. METHODS: Registry data were obtained from the SEER-18 Database, containing 6600 MCC cases. Age- and sex-adjusted projections were generated using US census data. RESULTS: During 2000-2013, the number of reported solid cancer cases increased 15%, melanoma cases increased 57%, and MCC cases increased 95%. In 2013, the MCC incidence rate was 0.7 cases/100,000 person-years in the United States, corresponding to 2488 cases/year. MCC incidence increased exponentially with age, from 0.1 to 1.0 to 9.8 (per 100,000 person-years) among age groups 40-44 years, 60-64 years, and ≥85 years, respectively. Due to aging of the Baby Boomer generation, US MCC incident cases are predicted to climb to 2835 cases/year in 2020 and 3284 cases/year in 2025. LIMITATIONS: We assumed that the age-adjusted incidence rate would stabilize, and thus, the number of incident cases we projected might be an underestimate. CONCLUSION: An aging population is driving brisk increases in the number of new MCC cases in the United States. This growing impact combined with the rapidly evolving therapeutic landscape warrants expanded awareness of MCC diagnosis and management.

Subungual atypical lentiginous melanocytic proliferations in children and adolescents: A clinicopathologic study.

BACKGROUND: Most subungual melanocytic lesions in children are benign, but some are difficult to classify due to prominent lentiginous growth and high-grade cytologic atypia. OBJECTIVE: To characterize the clinicopathologic features of these rare lesions. METHODS: Subungual atypical lentiginous melanocytic proliferations from patients <20 years of age were collected for clinical and histopathologic review. Fluorescence in situ hybridization (FISH) was performed when possible. RESULTS: Eleven patients aged 2-19 years had expanding or darkening longitudinal pigmented streak(s) with or without Hutchinson sign. Microscopically, all revealed predominantly single-cell growth, pagetoid scatter, and poor circumscription. Eight (73%) cases showed focal or poor nesting, and 3 (27%) demonstrated confluence. Nuclear enlargement, hyperchromasia, and angulation were present in 8 (73%) cases, 7 (64%) cases, and 6 (55%) cases, respectively. One of 4 cases tested by FISH was positive. Three lesions recurred locally without other adverse outcome. LIMITATIONS: Small sample size and short clinical follow-up. Two cases were examined in partial biopsies only. CONCLUSION: Some subungual melanocytic lesions in children and adolescents are histologically indistinguishable from adult subungual melanoma in situ. While the biologic potential remains elusive, FISH might aid in risk stratification. Awareness of this rare group of lesions is crucial for facilitating future investigation into its biologic behavior.

Characterization of pediatric golf cart injuries to guide injury prevention efforts.

BACKGROUND: Golf cart injuries represent an increasing source of morbidity and mortality in the United States. Characterization of the circumstances of these injuries can inform injury prevention efforts. METHODS: This study retrospectively reviews a prospective trauma registry at a level-one pediatric trauma center for golf cart-related injuries in patients under 18years of age admitted to the hospital between 2008 and 2016. RESULTS: The 40 identified crashes were associated with 82 hospital days, 17 ICU days, and more than $1 million in hospital charges over the study period. The median hospital stay was 1.5days, and the median hospital charge was $20,489. Severe injuries with an Injury Severity Score of >15 were identified in 25% of patients, and moderate injuries with scores between nine and 15 were identified in an additional 30%. The most common injures were head and neck (60%) and external injuries to the body surface (52.5%). Only a single child was wearing a seatbelt, and the vast majority was not using any safety equipment. Children as young as nine years old were driving golf carts, and child drivers were associated with the cart overturning (p=0.007). CONCLUSIONS: Golf cart crashes were a source of substantial morbidity at a level-one trauma center. Increased safety measures, such as higher hip restraints, seatbelts, and front-wheel breaks could substantially increase the safety of golf carts. Increased regulation of driving age as well as driver education may also reduce these injuries.

The natural history of thin melanoma and the utility of sentinel lymph node biopsy.

BACKGROUND AND OBJECTIVES: Current literature may overestimate the risk of nodal metastasis from thin melanoma due to reporting of data only from lesions treated with SLNB. Our objective was to define the natural history of thin melanoma, assessing the likelihood of nodal disease, in order to guide selection for SLNB. METHODS: Retrospective review. The primary outcome was the rate of nodal disease. Clinicopathologic factors were evaluated to find associations with nodal disease. RESULTS: Five hundred and twelve lesions, follow up available for 488 (median: 48 months). Lesions treated with WLE/SLNB compared to WLE alone were more likely to have high-risk features. The rate of nodal disease was higher in the WLE/SLNB group (24 positive SLNB, five false-negative SLNB with nodal recurrence: 10.2%) compared to WLE alone (four nodal recurrences: 2.0%). Univariate analysis showed age ≤45, Breslow depth ≥0.85 mm, mitotic rate >1 mm2 , and ulceration were associated with nodal disease. Multivariate analysis confirmed the association of age ≤45 and ulceration. CONCLUSIONS: SLNB for melanoma 0.75-0.99 mm should be considered in patients age ≤45, Breslow depth ≥0.85 mm, mitotic rate >1 mm2 , and/or with ulceration. Thin melanoma <0.85 mm without high-risk features may be treated with WLE alone.

Analysis of Prognostic Factors from 9387 Merkel Cell Carcinoma Cases Forms the Basis for the New 8th Edition AJCC Staging System.

BACKGROUND: The first consensus Merkel cell carcinoma (MCC) staging system was published in 2010. New information on the clinical course prompts review of MCC staging. METHODS: A total of 9387 MCC cases from the National Cancer Data Base Participant User File with follow-up and staging data (1998-2012) were analyzed. Prognostic differences based on clinical and pathological staging were evaluated. Survival estimates were compared by disease extent. RESULTS: Sixty-five percent of cases presented with local disease, whereas 26 and 8 % presented with nodal and distant disease. Disease extent at presentation was predictive of 5-year overall survival (OS) with estimates of 51, 35, and 14 % for local, nodal, and distant disease. Tumor burden at the regional nodal basin was predictive of 5-year OS with estimates of 40 and 27 % for clinically occult and clinically detected nodal disease. For local disease, we confirm improved prognosis when the regional nodal basin was negative by pathological compared with clinical staging. We identified 336 cases with clinically detected nodal disease and unknown primary tumor and showed improved prognosis over cases presenting with concurrent primary tumor (OS estimates of 42 vs. 27 %). CONCLUSIONS: Analysis of a national dataset of MCC cases validates the predictive value of disease extent at presentation. Separation of clinical and pathological stage groups and regrouping of unknown primary tumors are supported by the analysis. The revised staging system provides more accurate prognostication and has been formally accepted by the AJCC staging committee for inclusion in the 8th edition.

Increased minimum vein diameter on preoperative mapping with duplex ultrasound is associated with arteriovenous fistula maturation and secondary patency.

OBJECTIVE: Autogenous arteriovenous hemodialysis accesses (arteriovenous fistulas [AVFs]) are preferred for chronic hemodialysis access. Preoperative vein mapping by duplex ultrasound is recommended before AVF creation, but there are few data correlating vein diameter with postoperative outcomes. Also, vein diameter has not been included in prior predictive models of fistula maturation. This study aims to test whether preoperative vein diameter is associated with failure of AVF maturation and long-term (secondary) patency. METHODS: We performed a retrospective analysis of clinical variables of patients undergoing brachiobasilic or brachiocephalic AVF creation. Kaplan-Meier and multivariate Cox regression models tested whether preoperative minimum vein diameter (MVD) and clinical covariates were associated with failure of AVF maturation and secondary patency. RESULTS: The sample included 158 adults (54 ± 14 years; 45% male; 61% white; 56% diabetes; body mass index, 32 ± 8; MVD, 3.4 ± 1.1 mm; follow-up, 12 ± 9 months [range, <1-40 months]). Increased MVD was associated with decreased risk of AVF failure. More than one third of AVFs with MVD <2.7 mm failed to mature within 6 months. Multivariate models that adjusted for age, diabetes, race, gender, body mass index, and preoperative dialysis status demonstrated that increased MVD was associated with decreased risk of failure of maturation and better long-term patency overall (P = .005 and P = .001, respectively). CONCLUSIONS: Patients with a larger MVD on preoperative vein mapping are at lower risk for failure of fistula maturation and have increased long-term AVF patency. MVD is the only clinical or demographic factor associated with both AVF maturation and long-term patency. MVD is an important preoperative indicator of fistula success in assessment of potential AVF sites. Future predictive models of fistula maturation and patency should include MVD.

Validation of the Written Administration of the Short Literacy Survey.

Most health literacy assessments are time consuming and administered verbally. Written self-administration of measures may facilitate more widespread assessment of health literacy. This study aimed to determine the intermethod reliability and concurrent validity of the written administration of the 3 subjective health literacy questions of the Short Literacy Survey (SLS). The Rapid Estimate of Adult Literacy in Medicine (REALM) and the shortened test of Functional Health Literacy in Adults (S-TOFHLA) were the reference measures of health literacy. Two hundred ninety-nine participants completed the written and verbal administrations of the SLS from June to December 2012. Intermethod reliability was demonstrated when (a) the written and verbal SLS score did not differ and (b) written and verbal scores were highly correlated. The written items were internally consistent (Cronbach's α = .733). The written total score successfully identified persons with sixth-grade equivalency or less for literacy on the REALM (AUROC = 0.753) and inadequate literacy on the S-TOFHLA (AUROC = 0. 869). The written administration of the SLS is reliable, valid, and is effective in identifying persons with limited health literacy.

Mycosis fungoides with CD20 expression: report of two cases and review of the literature.

CD20 expression is exceedingly rare in T-cell lymphomas. Most published cases have been diagnosed as peripheral T-cell lymphomas, not otherwise specified. Only 18 cases of CD20-positive mycosis fungoides (MF) have been previously reported. Here, we describe two cases of CD20-positive MF. Patient 1 was an 84-year-old woman who presented with a 5-year history of multiple pruritic erythematous papules coalescing into thin plaques over 80% of her body surface area. She expired after developing tumors and large cell transformation. Patient 2 was a 67-year-old woman with a long-standing history of tumor stage MF with large cell transformation. She developed a nodular plaque while receiving topical and systemic therapy. In both cases, the neoplastic T-cells demonstrated a CD4-positive immunophenotype with loss of pan-T-cell markers and a monoclonal T-cell receptor gamma gene rearrangement. CD20 was expressed by a significant population of the neoplastic T-cells, but these T-cells lacked expression of other B-cell markers, including CD79a, CD19 and PAX5. This report adds to and summarizes the small body of literature describing CD20-positive MF, and discusses diagnostic and clinical implications.