Standardizing Retrospective Observational Research in Cutaneous Squamous Cell Carcinoma: Expert Panel Guidelines from ITSCC.

Importance: Cutaneous squamous cell carcinoma (CSCC) is the second most common malignant disease in the US. Although it typically carries a good prognosis, a subset of CSCCs are highly aggressive, carrying regional and distant metastatic potential. Due to its high incidence, this aggressive subset is responsible for considerable mortality, with an overall annual mortality estimated to equal or even surpass melanoma. Despite this morbidity, CSCC is excluded from national cancer registries, making it difficult to study its epidemiology and outcomes. Therefore, the bulk of the CSCC literature is composed of single-center and multi-institutional retrospective cohort analyses. Given variations in reporting measures and analyses in these studies, interpretability between studies and the ability to pool results are limited. Objective: To define standardized reporting measures for retrospective CSCC studies. Findings: An expert panel was convened to determine standardized guidelines for recording and analyzing retrospective CSCC data. A total of 13 dermatologists and dermatologic surgeons with more than 5 years of posttraining experience and considerable experience with performing CSCC outcomes research were recruited to the panel. Consensus recommendations were achieved for CSCC retrospective study reporting measures, definitions, and analyses. Conclusions and Relevance: The recommendations in this report present the potential to standardize future CSCC retrospective studies. With such standardization, future work may have greater interstudy interpretability and allow for pooled analyses.

Acute myeloid leukemia cutis with KMT2A::MLLT3 fusion presenting with leonine facies.

A 63-year-old woman presented with plaques covering 60 % body-surface-area and leonine facies. Blood work showed no diagnostic aberrancies. Skin biopsy contained a malignant CD4+/CD56+ mononuclear cell population concerning for blastic plasmacytoid dendritic cell neoplasm. A later bone marrow biopsy confirmed AML with KMT2A::MLLT10 fusion detected by next-generation sequencing (NGS). This patient's LC preceded blood and marrow based symptoms of AML. NGS of the initial skin biopsy should be considered as part of diagnostic guidelines in cases with LC in the differential as this may have led to earlier diagnosis in this case and future cases.

Adnexotropic and granulomatous mycosis fungoides following TNF-α inhibitor treatment.

Recent publications have documented an increased prevalence of cutaneous T-cell lymphoma (CTCL) in patients undergoing tumor necrosis factor alpha (TNF-α) inhibitor therapy. Herein, we present an uncommon manifestation of mycosis fungoides (MF) with unique pathological findings after the initiation of adalimumab therapy for the treatment of psoriasis. One year after starting treatment, the patient noticed a slowly growing, eroded plaque on the left cheek, the biopsy of which demonstrated mixed granulomatous and adnexotropic lymphocytic infiltrate with features characteristics of MF. In the following months, the patient developed pink- and violet-colored scaly plaques on the right posterior upper arm and right medial upper arm. Biopsy of these plaques also revealed findings compatible with MF. T-cell receptor (TCR) clonality studies by PCR revealed identical T-cell clones in the samples obtained from the cheek, right posterior upper arm, and right medial upper arm. TCR clonality studies of a long-standing psoriatic plaque on the right thigh failed to reveal similar T-cell clones. Blurring of histopathologic presentation by TNF-α inhibitors could greatly complicate the identification of MF subtypes. Providers treating patients with TNF-α inhibitors must be aware of the risk of cutaneous lymphoma development and the potential deviations from their expected presentations. In patients without an initial biopsy, the possibility of pre-existing CTCL with psoriasiform presentation should be considered.

A Practical Review of the Presentation, Diagnosis, and Management of Cutaneous B-Cell Lymphomas.

This review of cutaneous B-cell lymphoma (CBCL) is focused on the clinical presentation, treatment, and workup of each type of lymphoma. Part 1 is an overview of each of the CBCLs, including clinical presentation, recent advances in the pathobiology, and evidence regarding treatment strategies. Part 2 is a detailed guide to the steps in diagnosis and workup of a newly diagnosed CBCL according to the International Society for Cutaneous Lymphoma/European Organization for Research and Treatment of Cancer and NCCN guidelines.

Primary cutaneous gamma-delta T-cell lymphoma masquerading as leukemia cutis in a patient recently diagnosed with small lymphocytic lymphoma: Clues to the diagnosis.

A 54-year-old man recently diagnosed with small lymphocytic lymphoma (SLL) had waxing and waning, indurated, erythematous plaques on his legs, with leukopenia and anemia disproportionate to the SLL burden in his marrow and pelvic lymph nodes. Punch biopsy of a plaque performed to evaluate for leukemia cutis revealed a lymphocytic lobular-panniculitis-like infiltrate resembling lupus panniculitis, but a preponderance of CD8+/Ki-67+ T-cells surrounding adipocytes raised concern for subcutaneous panniculitis-like T-cell lymphoma (SPTCL). Additional immunohistochemistry (IHC) studies showed that the adipotropic T-cells expressed TCR-gamma, supporting the rare, unexpected diagnosis of Primary cutaneous gamma-delta T-cell lymphoma (PCGDTCL). The patient subsequently met diagnostic criteria for hemophagocytic lymphohistiocytosis (HLH). PCGDTCL is an aggressive, HLH-associated lymphoma requiring different management than SPTCL and SLL. This case illustrates how PCGDTCL can co-exist with B-cell lymphoma and resemble panniculitis on biopsies. PCGDTCL and SPTCL should enter the differential diagnosis whenever patients present with the constellation of lobular panniculitis and unexplained cytopenias. In the present case, close clinicopathologic correlation and judicious use of IHC on a small sample allowed for a prompt diagnosis.

Small lymphocytic lymphoma mimicking primary cutaneous marginal zone lymphoma with colonization of germinal center follicles.

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is primarily a disease of older adults and is occasionally an incidental finding on skin biopsies accompanying epithelial neoplasms and insect bite reactions. In rare instances, however, it produces leukemic infiltrates showing clinical and histopathologic overlap with primary cutaneous B-cell lymphomas including primary cutaneous marginal zone lymphoma (PCMZL). Even less frequently, such findings serve as the initial disease manifestation. We present an exceptional case of a 61-year-old man with no past medical history whose clinical and histopathologic findings raised consideration for PCMZL with abnormal B-cells colonizing germinal center follicles; however, faint CD5 and CD23 co-expression raised the differential diagnosis of CLL/SLL. In light of an ambiguous clinical presentation with widely distributed papules and plaques, peripheral blood flow cytometry was also performed, revealing high count of CLL-type monoclonal B lymphocytosis. Subsequent workup revealed bone marrow involvement and mesenteric lymphadenopathy, supporting the diagnosis of SLL. Follicular colonization by SLL has not been previously reported. Our case underscores the importance of subtle immunophenotypic clues and correlations with clinical and radiologic findings in the workup of B-cell lymphomas presenting in the skin.

Phototherapy for Cutaneous T-Cell Lymphoma.

Phototherapy with psoralen and ultraviolet A (PUVA) or narrowband-UVB (NBUVB) is frequently used for the patch and plaque stages of mycosis fungoides (MF), the most common type of cutaneous T-cell lymphoma. This article provides practical guidelines for the design and implementation of a phototherapy protocol for early stage MF, including an overview of treatment phases, response criteria, and considerations in the selection of a light source. Several evolving topics in phototherapy research are also discussed, including the relative efficacy of PUVA versus NBUVB, the role of maintenance therapy, risk of photocarcinogenicity, and combination therapies.

Adenopathy and extensive skin patch overlying a plasmacytoma with unusual histologic findings in a patient with polyneuropathy, organomegaly, endocrinopathy, monoclonal protein and skin changes syndrome and Castleman disease.

A 56-year-old previously healthy man presented to the dermatology clinic with a 2-year history of an expanding, violaceous, infiltrated plaque on the right flank. Biopsy revealed a diffuse dermal vascular proliferation of bland, capillary-sized vessels admixed with conspicuous fibrohistiocytic cells including scattered multinucleated floret cells. Further workup revealed a monoclonal gammopathy, an osteolytic chest wall plasmacytoma underlying the plaque, and regional lymphadenopathy leading to a diagnosis of adenopathy and extensive skin patch overlying a plasmacytoma (AESOP). Biopsy of an enlarged lymph node revealed Castleman disease. The patient subsequently developed polyneuropathy and peripheral edema, which supported an additional diagnosis of polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes (POEMS) syndrome. Herein, we discuss the unique findings of our patient, the potential pathogenesis of AESOP, and the link between these three rare paraneoplastic entities along with review of the literature.

Automated detection of nonmelanoma skin cancer using digital images: a systematic review.

BACKGROUND: Computer-aided diagnosis of skin lesions is a growing area of research, but its application to nonmelanoma skin cancer (NMSC) is relatively under-studied. The purpose of this review is to synthesize the research that has been conducted on automated detection of NMSC using digital images and to assess the quality of evidence for the diagnostic accuracy of these technologies. METHODS: Eight databases (PubMed, Google Scholar, Embase, IEEE Xplore, Web of Science, SpringerLink, ScienceDirect, and the ACM Digital Library) were searched to identify diagnostic studies of NMSC using image-based machine learning models. Two reviewers independently screened eligible articles. The level of evidence of each study was evaluated using a five tier rating system, and the applicability and risk of bias of each study was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. RESULTS: Thirty-nine studies were reviewed. Twenty-four models were designed to detect basal cell carcinoma, two were designed to detect squamous cell carcinoma, and thirteen were designed to detect both. All studies were conducted in silico. The overall diagnostic accuracy of the classifiers, defined as concordance with histopathologic diagnosis, was high, with reported accuracies ranging from 72 to 100% and areas under the receiver operating characteristic curve ranging from 0.832 to 1. Most studies had substantial methodological limitations, but several were robustly designed and presented a high level of evidence. CONCLUSION: Most studies of image-based NMSC classifiers report performance greater than or equal to the reported diagnostic accuracy of the average dermatologist, but relatively few studies have presented a high level of evidence. Clinical studies are needed to assess whether these technologies can feasibly be implemented as a real-time aid for clinical diagnosis of NMSC.

Combined Modality Treatment With Brentuximab Vedotin and Radiation Therapy for Primary Cutaneous Anaplastic Large Cell Lymphoma: A Case Report.

Primary cutaneous anaplastic large cell lymphoma (pcALCL) is a rare form of non-Hodgkins lymphoma. Current frontline treatments for pcALCL include surgical resection, anthracycline-based chemotherapy, and/or radiation therapy (RT) depending on disease severity. While brentuximab vedotin (BV) has been used for refractory/relapsed cases, it recently received Food and Drug Administration (FDA) approval for use in combination with chemotherapy for peripheral T-cell lymphomas. In this case report, we utilized a combined modality therapy of RT and BV for a limited stage aggressive pcALCL presentation for which routine management is contraindicated. A 59-year-old man with a history of peripheral vascular disease (PVD) presented with an aggressive pcALCL involving the left inferior eyelid and small ipsilateral level II hypermetabolic lymph nodes at stage IIE. Due to the patient's history of PVD, the tumor's rapid growth, possible lymph node involvement, and eye proximity, BV was chosen as the initial chemotherapy treatment followed by RT. Complete metabolic resolution of the primary cutaneous lesion and lymphadenopathy was reached after BV treatment alone; complete clinical response of the primary tumor was reached following radiation therapy. Relapse occurred within 7 months. Salvage cyclophosphamide, vincristine, etoposide, and prednisone were not effective. Retreatment with BV + RT is currently being used to treat the new lesions. Our case illustrates that a combination of BV and RT can be a safe and effective initial treatment in patients with limited stage pcALCL who cannot tolerate anthracycline-based chemotherapy. Our patient had a complete response but ultimately relapsed; thus larger clinical trials are needed to better understand early-stage disease.

Cutaneous B-Cell Lymphoma.

Primary cutaneous B-cell lymphomas are non-Hodgkin lymphomas that present in the skin without evidence of extracutaneous involvement at diagnosis. There are 3 types of primary cutaneous B-cell lymphomas: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B-cell lymphoma, leg-type. Because it is most frequently diagnosed on skin biopsy, intravascular large B-cell lymphoma is commonly included with pcBCL. A complicating factor in diagnosing primary cutaneous B-cell lymphomas is that they can appear histologically identical to their extracutaneous counterparts. This review summarizes the clinical presentation, histopathology, evaluation, treatment, and differential diagnosis of these lymphomas.

Angiolymphoid hyperplasia with eosinophilia and Kimura disease overlap, with evidence of diffuse visceral involvement.

A relationship between Kimura disease (KD) and angiolymphoid hyperplasia with eosinophilia (ALHE) has been debated. Given substantial clinical and histological overlap, these entities were once considered to represent a disease spectrum; however, they are now widely considered to be nosologically distinct. A diagnosis of either condition is further complicated by resemblance to various malignancies, which must be carefully excluded. Coexistence of ALHE and KD in a patient is extremely rare, with only four cases reported in the English literature. We report what is to our knowledge the first case of ALHE and KD overlap with evidence of diffuse visceral involvement.

Tumor-stage mycosis fungoides in palmoplantar localization with large-cell transformation and partial CD30 expression shows complete response to brentuximab vedotin.

Mycosis fungoides in palmoplantar localization (MFPP) is a rare variant of MF that is confined to the hands and feet. Patients commonly receive treatment over many years for suspected palmoplantar dermatitis before the diagnosis is made. Most MFPP patients remain at patch or plaque stage, and often respond to treatment with radiotherapy. Herein, we describe a 77-year-old man who suffered 6 years of hand and foot dermatitis that failed multiple treatments, most notably TNF-α inhibitors and mycophenolate mofetil. He eventually developed a tumor on the hand, which was biopsied to reveal a dense dermal infiltrate of large lymphocytes (CD3+/CD4-/CD8-/TCR-BetaF1+/partial CD30+). A subsequent biopsy of an eczematous patch from his hand revealed an epidermotropic and syringotropic infiltrate comprised of smaller lymphocytes with a concordant immunophenotype and matching clonal peak with TCR gene rearrangement. He was diagnosed with MFPP and started on radiotherapy with a modest response; therefore, a decision was made to start brentuximab vedotin, which resulted in a complete response. MFPP is an exceedingly rare variant of MF that can show large-cell transformation and progress in stage. We highlight a possible association between disease progression and immunosuppressants and the potential role for treatment with brentuximab.

Epidermotropic presentation by splenic B-cell lymphoma: The importance of clinical-pathologic correlation.

There are exceedingly rare reports of patients with epidermotropic B-cell lymphomas. A subset presented with intermittent, variably pruritic papular eruptions and involvement of their spleens, peripheral blood and bone marrow at the time of diagnosis. Furthermore, some experienced an indolent course despite dissemination of their lymphomas. We report a 66-year-old woman with a 12-year history of intermittent eruptions of non-pruritic, salmon-colored papules on her torso and proximal extremities that occurred in winter and resolved with outdoor activity in spring. Skin biopsy revealed an epidermotropic B-cell lymphoma with a non-specific B-cell phenotype and heavy chain class switching with IgG expression. On workup, our patient exhibited mild splenomegaly and low-level involvement of her peripheral blood and bone marrow by a kappa-restricted B-cell population. A splenic B-cell lymphoma was diagnosed. Considering her longstanding history and absences of cytopenias, our patient has been followed without splenectomy or systemic therapy. Furthermore, the papules have responded dramatically to narrowband UVB. Our case and a review of similar rare reports aim to raise awareness among dermatopathologists and dermatologists of a clinically distinct and indolent subset of epidermotropic splenic lymphomas with characteristic clinical and histologic findings.