Dermatopathologic features of cutaneous squamous cell carcinoma and actinic keratosis: Consensus criteria and proposed reporting guidelines.

BACKGROUND: There is considerable variation in the literature regarding the dermatopathologic diagnostic features of and reporting guidelines for actinic keratosis (AK) and cutaneous squamous cell carcinoma (cSCC). OBJECTIVE: To develop consensus recommendations regarding diagnostic criteria, nomenclature, and reporting of AK and cSCC. METHODS: Literature review and cross-sectional multiround Delphi process including an international group of expert dermatopathologists followed by a consensus meeting. RESULTS: Consensus was achieved regarding the key dermatopathologic features necessary for diagnosing cSCC, AK, and associated variants; grading of degree of cellular differentiation in cSCC; utility of immunohistochemistry for diagnosis of cSCC; and pathologic features that should be reported for cSCC and AK. LIMITATIONS: Consensus was not achieved on all questions considered. CONCLUSION: Despite the lack of clarity in the literature, there is consensus among expert dermatopathologists regarding diagnostic criteria and appropriate reporting of AK and cSCC. Widespread implementation of these consensus recommendations may improve communication between dermatopathologists and clinicians, facilitating appropriate treatment of AK and cSCC.

Cutaneous adverse events in 155 patients with metastatic melanoma consecutively treated with anti-CTLA4 and anti-PD1 combination immunotherapy: Incidence, management, and clinical benefit.

BACKGROUND: In response to the increased use of combination checkpoint inhibitors (CPIs) and the resulting increased cutaneous adverse events (CAEs), this study reviewed patients with melanoma treated with combination CPIs to characterize CAE features and their clinical impact, correlation to adverse events in other organs, and correlation to tumor response. METHODS: Patients from the authors' institutional database who received at least 1 dose of ipilimumab in combination with either nivolumab or pembrolizumab between January 1, 2012, and December 31, 2017, for stage IV or unresectable stage III melanoma were identified. The time to next treatment (TTNT) was calculated from the start of CPI therapy to the start of the next treatment or death, and the development of CAEs was tested in a time-dependent Cox regression to identify associations with TTNT. RESULTS: Eighty-one patients (52.3%) experienced a total of 92 CAEs, including eczematous dermatitis (25.0%), morbilliform eruption (22.8%), vitiligo (12.0%), and pruritus without rash (8.7%). The median times to the onset and resolution of CAEs were 21 days (range, 0-341 days) and 50 days (range, 1-352 days), respectively. Most CAEs resolved after patients entered the CPI maintenance phase and treatment with oral antihistamines with or without topical steroids. CPI discontinuation occurred in 4 patients (2.6%) because of CAEs, in 49 (31.6%) because of other immune-related adverse events, and in 20 (12.9%) because of melanoma progression or death. For patients definitively treated with CPIs (n = 134; 86.5%), TTNT was significantly longer with CAEs than without CAEs (hazard ratio, 0.567; 95% CI, 0.331-0.972; P = .039). CONCLUSIONS: CAEs were mostly reversible and rarely required therapy discontinuation. The development of CAEs was associated with a longer TTNT, and this suggested a possible clinical benefit.

Diverse types of dermatologic toxicities from immune checkpoint blockade therapy.

Immunomodulatory drugs that leverages host immune mechanisms to destroy tumor cells have been met with great promise in the treatment of cancer. Immunotherapy, targeting cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and the programmed cell death 1 (PD-1) receptor and its ligand (PD-L1) have shown tremendous improvements in the survival of patients with advanced solid tumors. However, the development of dermatologic toxicity (DT) is a consequence to immunotherapy. Review of published reports of the DT to immunotherapy revealed patients receiving anti-CTCLA-4 antibody or anti-PD-1/PD-L1 antibody often develop a DT of any type and grade. In this article, of the 3825 patients who were treated with anti-PD-1 and of 556 patients receiving anti-PD-L1, DT of any type and grade were reported in 1474 (∼39%) and 95 (∼17%) of patients, respectively. The emergence of specific types of DT to immunotherapy is beginning to be recognized can be categorized into four groups: (a) inflammatory, (b) immunobullous, (c) alteration of keratinocytes and (d) alteration of melanocytes. Lichenoid dermatitis and bullous pemphigoid appear to be DT more associated with anti-PD-1/PD-L1 antibody. The DT profile in patients receiving immunotherapy is diverse, and early recognition of specific types of DT that clinicians may encounter is critical for optimal patient care.

Concomitant Cutaneous Langerhans Cell Hystiocytosis and Leukemia Cutis.

Leukemia cutis develops in <4% of all acute leukemias. Concurrent acute myeloid leukemia (AML) and Langerhans cell histiocytosis (LCH) is rare, with most cases involving lymph nodes or spleen, and no cutaneous involvement. We report the case of a 59-year-old man who presented with fever, malaise, and fatigue. The CBC showed leukocytosis (30.4 × 10/L, 9% blasts), anemia, and thrombocytopenia. Bone marrow biopsy was diagnosed with AML, not otherwise specified, with mutations of FLT3 and IDH2 (R140Q). The patient developed skin rash on the right flank with the clinical differential diagnosis of herpes simplex virus or varicella-zoster virus infection/reactivation versus leukemia cutis. A skin biopsy showed leukemia cutis in mid and deep dermis. Immunohistochemistry positive for CD4, CD33, CD117, and myeloperoxidase (MPO) supported myeloid and monocytic differentiation. Clusters of Langerhans cells positive for S100, CD1a, CD4, langerin and aberrant CD33 and MPO were found admixed with the AML cells. Langerhans cells were negative for BRAF V600E by immunohistochemistry. The diagnosis of leukemia cutis and concomitant LCH was established. The aberrant expression of CD33 and MPO shared by AML and LCH suggests a possible relationship among these 2 lesions. No LCH or Langerhans cell differentiation was found in the bone marrow. The patient achieved complete remission 4 months after chemotherapy and the skin lesions resolved. To our knowledge, we present for the first time a case of concomitant cutaneous LCH and leukemia cutis.

Autoimmune dermatologic toxicities from immune checkpoint blockade with anti-PD-1 antibody therapy: a report on bullous skin eruptions.

Monoclonal antibodies against the immune checkpoint programmed cell death receptor 1 (PD-1) improve the hosts' antitumor immune response and have showed tremendous promise in the treatment of advanced solid tumors and hematologic malignancies. Reports of serious autoimmune dermatologic toxicities from immune checkpoint blockade therapy, however, are emerging. We report our experience with five patients who presented with pruritic vesicles and blisters on the skin while treated with anti-PD-1 antibody immunotherapy with either nivolumab or pembrolizumab. Four of the patients' skin biopsies revealed subepidermal bullae with immunohistochemical study for type IV collagen labeling the floor of the blister cavity and direct immunofluorescence studies (in three of the four patients tested) decorated linear IgG and C3 immune deposits on the blister roof, diagnostic of bullous pemphigoid. One patient developed bullous erythema multiforme. All patients had partial or complete resolution of skin lesions following treatment with systemic corticosteroid and cessation of checkpoint blockade. Recognition and treatment of rare immune-related bullous dermatologic toxicities will become increasingly important as more patients are treated with effective and newer immune checkpoint blockade therapy.

Grape Cells (Multinucleated Keratinocytes) in Noninfectious Dermatoses: Case Series and Review of the Literature.

Multinucleated keratinocytes (also known as multinucleated epidermal giant cells) are a frequently overlooked histological finding in noninfectious inflammatory dermatoses. They are sometimes found in conditions characterized by chronic rubbing and pruritus, such as lichen simplex chronicus or prurigo nodularis, and may be a helpful clue in making the clinical diagnosis. This finding must be differentiated from other conditions characterized by multinucleated keratinocytes on histopathology, specifically herpes simplex, varicella zoster, or measles viral infections. The authors present a case series of 2 patients with unique clinical noninfectious diagnoses but similar histopathologic findings on biopsy. The histopathologic findings on both cases demonstrated multinucleated keratinocytes, which were related to manipulation of the epidermis.

Panniculitis With Necrotizing Granulomata in a Patient on BRAF Inhibitor (Dabrafenib) Therapy for Metastatic Melanoma.

There have been major developments in targeted therapeutics with the clinical development of selective BRAF inhibitors (BRAFi) for patients with metastatic BRAF V600E mutant melanoma. Objective response rate of almost 50% has been witnessed in BRAFi clinical trials. Frequent side effects range from squamoproliferative lesions, including hyperplasia, keratoacanthomas, and squamous cell carcinomas to second primary melanomas. We describe a 50-year-old Hispanic woman with BRAF V600E mutant metastatic melanoma who was treated with surgery, radiation therapy, interleukin-2, and was enrolled on a BRAFi (dabrafenib) trial. Two months after initiation, she developed multiple erythematous, indurated, tender subcutaneous nodules bilaterally on the anterior thighs, posterior arms, and left dorsal forearm without overlying epidermal change. Punch biopsy revealed panniculitis with necrotizing granulomata. Infectious and other causes for panniculitis were excluded. We believe the histology likely represents a reaction to BRAFi therapy based on the temporal relationship of its onset to initiation of BRAFi therapy and previously reported cases of neutrophilic panniculitis associated with BRAFi therapy. Panniculitis has been emerging as an important unusual side effect of BRAFi therapy. Our case illustrates a unique presentation of BRAFi-associated panniculitis demonstrating necrotizing granulomata.

Morphea-like complications to illicit gluteal silicone injections.

We present a case of a 39-year-old Hispanic woman who was referred to our clinic for treatment of several indurated plaques on her buttocks that developed one year prior to presentation, after she received injections of an unknown substance for augmentation. Biopsy of one nodule revealed silicone in the dermis.

Syringocystadenocarcinoma papilliferum with transition to areas of squamous differentiation: a case report and review of the literature.

Syringocystadenocarcinoma papilliferum (SCACP) is an exceedingly rare cutaneous adnexal neoplasm, which is typically located in the head and neck, and perianal area. Very few cases have been reported in the literature. Here, we report a case of SCACP with evident transition to squamous differentiation. A 75-year-old white woman presented with 1-year history of a solitary tender nodule in the left upper arm. Physical examination revealed a single, 1.5 × 1.1-cm, erythematous ulcerated nodule within a background of red patch. Biopsy showed an adnexal carcinoma connected to the epidermis and composed of cystic papillary projections admixed with solid basaloid areas with marked cytologic atypia. The basaloid tumor cells appeared to blend with the squamous component that demonstrated ductal formation, which was highlighted by carcinoembryonic antigen. Tumor cells were reactive for both cytokeratins 5/6 and 7. This case represents SCACP arising from syringocystadenoma papilliferum in the upper arm, with distinct transition to areas of squamous differentiation.

Pityriasis rosea-like rash after messenger RNA COVID-19 vaccination: A case report and review of the literature.

A spectrum of cutaneous reactions to SARs-CoV-2 (COVID-19) vaccines have been reported in the literature. We present a case of a pityriasis rosea-like rash occurring after Pfizer COVID-19 vaccination and review cases of pityriasis rosea (PR)/PR-like eruption (PR-LE) after mRNA COVID-19 vaccine published in the medical literature. Of the 30 cases found, none experienced severe adverse effects and the rash resolved in an average of 5.6 weeks. It is important for physicians to be aware of this self-limited reaction so they can reassure and appropriately counsel patients that it is safe to receive subsequent vaccine doses despite the cutaneous eruption. Additionally, differences in incidence of this reaction after Pfizer and Moderna vaccination may suggest a differing host immune response incited by these vaccines which warrants further investigation.

Milestones 2.0: An advancement in competency-based assessment for dermatology.

In 2013, Next Accreditation System and Milestones became the competency-based assessment framework required for all specialties accredited by the Accreditation Council for Graduate Medical Education. Dermatology residency programs implemented Milestones 1.0 in the 2013-2014 academic year. The Accreditation Council for Graduate Medical Education committed to review and revise Milestones 1.0 within 3 to 5 years. Subsequently, feedback from key stakeholders influenced the goals for revision, including reducing complexity, enhancing community engagement, and providing additional resources for programs. In 2019, the Dermatology Milestones 2.0 work group streamlined the specialty-specific patient care and medical knowledge subcompetencies. The harmonized milestones allowed for greater uniformity across specialties in systems-based practice, practice-based learning and improvement, professionalism, and interpersonal communication and skills. The work group developed a supplemental guide with specialty-specific context to help program directors, clinical competency committee members, and other faculty understand individual milestones. Dermatology Milestones 2.0 reduces the number of subcompetencies from 28 to 21. Milestones 2.0 represents an advancement in competency-based assessment for dermatology. The first year of reporting for Dermatology Milestones 2.0 is 2021.

What's Eating You? Caterpillars.

Caterpillar envenomation is a worldwide problem, with manifestations ranging from dermatitis to iridocyclitis and a fatal hemorrhagic diathesis. This article focuses on the diagnosis and management of dermatoses related to caterpillars.

Dermatologic manifestations of colonic disorders.

PURPOSE OF REVIEW: The skin is often a mirror for matters of internal diseases including disorders of the gastrointestinal tract. Here we enumerate many cutaneous and gastrointestinal associations and focus closely on three of the lesser known cutaneous manifestations of colonic disorders. RECENT FINDINGS: Muir-Torre syndrome involves cutaneous sebaceous adenomas and internal malignancy; screening of cutaneous lesions for microsatellite instability, and absence of mismatch repair genes provides an opportunity for diagnosis of the syndrome. Degos' disease is a vasoocclusive disorder involving the cutaneous and gastrointestinal systems; this disease affects all ages with significant mortality, yet a benign variant only affecting the skin is described. Anecdotally reported treatments are listed. Metastatic Crohn's disease is the development of noncaseating granulomas at skin sites not contiguous with the gastrointestinal tract; cutaneous lesions may precede the onset of colonic disease or appear in the absence of active bowel disease, and extensive surgical debridement of perineal lesions is often necessary. SUMMARY: Knowledge of these cutaneous manifestations provides an insight into the state of colonic health. These clues alert the clinician to the potential for life-threatening consequences, which leads to vigilant screening and hopefully earlier diagnosis.

Erythrasma.

This case report describes well-demarcated brown plaques with overlying fine scale in the bilateral axillae, inframammary folds, and inguinal folds and widespread coral-red fluorescence.

Epidermolysis bullosa acquisita occurring in 2 patients with hepatitis C.

We report 2 patients with documented chronic hepatitis C infection and epidermolysis bullosa acquisita (EBA). Both patients clinically represent classic EBA, exhibiting skin fragility and blistering occurring both spontaneously and secondary to trauma, which heal with milia and scar formation. EBA often is a disease of altered immune status and debility. Further work is necessary to show whether hepatitis C plays a causative role in EBA in these 2 patients and in general.

Relapsing polychondritis.

Relapsing polychondritis is a rare disease most commonly presenting as inflammation of the cartilage of the ears and nose. Auricular chondritis, with red ears resembling infectious cellulitis, is the most common initial finding. Antibodies to type II collagen in cartilage are found, and the earlobes are classically spared. Chronic disease may result in a flabby, droopy ear, cauliflower ear, or saddle nose deformity. Acute involvement of the tracheal cartilage may cause collapse of the airway with obstruction and pulmonary infections. Arthritis may be oligoarticular or polyarticular, most often involving the costochondral junctions. Other manifestations include audiovestibular damage; heart valve disease; and neurologic, ocular, and renal disease. Corticosteroids remain the major treatment. Other therapies include nonsteroidal anti-inflammatory drugs, dapsone, colchicine, azathioprine, methotrexate, cyclophosphamide, hydroxychloroquine, cyclosporine, and infliximab.