Soluble adenylyl cyclase contributes to imiquimod-mediated inflammation and is a potential therapeutic target in psoriasis.

Cyclic AMP (cAMP) has a key role in psoriasis pathogenesis, as indicated by the therapeutic efficacy of phosphodiesterase inhibitors that prevent the degradation of cAMP. However, whether soluble adenylate cyclase (sAC) (encoded by the ADCY10 gene), which is an important source for cAMP, is involved in Th17 cell-mediated inflammation or could be an alternative therapeutic target in psoriasis is unknown. We have utilized the imiquimod model of murine psoriasiform dermatitis to address this question. Adcy10-/- mice had reduced erythema, scaling and swelling in the skin and reduced CD4+ IL17+ cell numbers in the draining lymph nodes, compared with wild-type mice after induction of psoriasiform dermatitis with imiquimod. Keratinocyte-specific knock out of Adcy10 had no effect on imiquimod-induced ear swelling suggesting keratinocyte sAC has no role in imiquimod-induced inflammation. During Th17 polarization in vitro, naive T cells from Adcy10-/- mice exhibited reduced IL17 secretion and IL-17+ T-cell proliferation suggesting that differentiation into Th17 cells is suppressed without sAC activity. Interestingly, loss of sAC did not impact the expression of Th17 lineage-defining transcription factors (such as Rorc and cMaf) but rather was required for CREB-dependent gene expression, which is known to support Th17 cell gene expression. Finally, topical application of small molecule sAC inhibitors (sACi) reduced imiquimod-induced psoriasiform dermatitis and Il17 gene expression in the skin. Collectively, these findings demonstrate that sAC is important for psoriasiform dermatitis in mouse skin. sACi may provide an alternative class of topical therapeutics for Th17-mediated skin diseases.

Early Fractional Ablative Laser for Skin Cancer Excision Scars: A Randomized Split-Scar Study.

BACKGROUND: Fractional ablative laser resurfacing has been shown to improve the final cosmetic appearance of surgical scars, but optimal timing is unknown. OBJECTIVE: To compare surgical scars treated with fractional carbon dioxide (CO 2 ) laser performed on Day 0 and Day 14. METHODS: Prospective, randomized, split-scar, physician-blinded study of 30 surgical scars on the limbs. Scars halves received fractional CO 2 laser on either Day 0 or Day 14. Scar assessment at 6 months evaluated patient preference, physician modified Manchester Scar Scale (MMSS) score, and quantitative scar analysis on histology (fractal dimension [F D ] and lacunarity [L] analysis). RESULTS: There was no significant difference in patient assessment (54% preferred Day 0 side, 46% preferred Day 14 side, p = .58) or physician assessment (mean MMSS 8.4 for Day 0 vs 8.7 for Day 14, p = .28). Fractal dimensions were similar for both interventions (mean 1.778 for Day 0 vs 1.781 for Day 14, p = .80). Lacunarity was similar for both interventions (mean 0.368 for Day 0 vs 0.345 for Day 14, p = .44). LIMITATIONS: Single-center study with wounds limited to limbs of skin Phototype I-II subjects; 4 of whom were lost to follow-up. CONCLUSION: Intraoperative CO 2 laser is noninferior to Day 14 laser resurfacing for surgical scar treatment.

Resolution of pembrolizumab-associated lichenoid dermatitis with a single dose of methotrexate.

We present a 53-year-old woman with severe lichenoid dermatitis secondary to pembrolizumab therapy that was refractory to both topical and oral steroids. After almost three months without improvement, the rash was effectively combated with a single 15mg dose of methotrexate. We hope this case will help guide the management of the cutaneous adverse effects of anti-PD1 immunotherapy.

Distinguishing pustular psoriasis and acute generalized exanthematous pustulosis on the basis of plasmacytoid dendritic cells and MxA protein.

BACKGROUND: Distinguishing acute generalized exanthematous pustulosis (AGEP) and pustular psoriasis (PS) can be challenging. Staining for plasmacytoid dendritic cells, or PDCs (producer of IFN-α/ß), and MxA (an IFN-α/ß inducible protein) may help discriminate these entities. METHODS: Forty-three cases of AGEP and PS were compiled from two academic institutions. All cases were examined for CD123+ PDCs, eosinophils, acanthosis, papillomatosis, suprapapillary plate thinning, tortuous dilated capillaries, single necrotic keratinocytes, papillary dermal edema, vasculitis, eosinophil exocytosis, intraepidermal pustules, and subcorneal pustules. A subset of cases (n = 26) was stained for MxA. RESULTS: Perivascular and intraepidermal PDCs, dilated tortuous vessels, and MxA expression in the dermal inflammatory infiltrate were significantly (P < 0.05) in favor of a diagnosis of PS. The absence of PDCs and presence of eosinophils favored a diagnosis of AGEP (P < 0.05). CONCLUSIONS: We found compelling evidence for the use of CD123 to highlight PDCs in these cases. The presence of PDCs and expression of MxA in dermal inflammatory infiltrate, as well as absence of eosinophils and presence of tortuous dilated capillaries favored a diagnosis of PS. Expression of MxA in the dermal infiltrate corresponds with a Th1 pathway in PS and may indicate a Th1 component in the early initial phase of AGEP.

Observational Study Examining the Diagnostic Practice of Ki67 Staining for Melanocytic Lesions.

BACKGROUND: Dermatopathologists routinely use Ki67 immunostaining to assess atypical melanocytic lesions with a dermal component to determine whether an ambiguous tumor is melanoma. However, there is no universal standard of use for Ki67 in melanocytic neoplasms. We sought to observe the real-world use of Ki67 in the diagnosis of melanocytic lesions and establish a best practice recommendation. METHODS: We searched dermatopathology reports from 2 academic practices for melanocytic lesions in which Ki67 staining was used for diagnosis. The proliferation rate was compared between cases diagnosed as benign (not requiring re-excision), moderate to severely dysplastic or atypical Spitz nevi (requiring re-excision), and malignant melanoma. The use of other melanocytic markers and consensus review was also recorded and compared between institutions. RESULTS: Pathology reports for 106 cases were reviewed. A high Ki67 proliferation rate (n = 18) favored a diagnosis of melanoma or nevi requiring re-excision (15/18, 83.3%) versus a benign nevus (3/18, 16.67%). A high Ki67 rate was 71.4%-90.9% sensitive and 40%-56% specific for the diagnosis of nevus requiring re-excision or melanoma. Institutional practices differed in regard to reporting of Ki67 staining, the use of multiple markers in the workup of atypical melanocytic lesions (HMB45, Melan-A, Ki67 being most common), and consensus review. CONCLUSIONS: A negative or low Ki67 proliferation rate correlates well with rendering of a benign diagnosis. However, a low proliferation rate does not preclude the diagnosis of melanoma. Ki67 staining is most commonly used as an ancillary test to support a diagnosis after other factors have been considered, such as histopathologic morphology and results of additional concurrently used stains.

Squamous cell carcinoma with enteric adenocarcinomatous differentiation.

We report a highly unusual case of a primary cutaneous squamous cell carcinoma (SCC) with intermixed enteric-type adenocarcinomatous dedifferentiation and a small component of undifferentiated mesenchymal differentiation. We believe this is the first time this form of phenotypic plasticity has been described in cutaneous SCC.

Cutaneous/subcutaneous mesenchymal proliferations of the breast.

Cutaneous mesenchymal "spindle cell" lesions arising in the vicinity of the breast represent a complex clinical and diagnostic scenario which may overlap histopathologically and immunohistochemically with mammary spindle cell proliferations, potentially impacting management and overall prognostication. In this review, we suggest a pattern-based approach to assist in the evaluation of these lesions. A comprehensive description of each entity is accompanied by a cutaneous and mammary differential diagnosis.

Giant benign intradermal melanocytic nevus of rapid onset.

Benign melanocytic nevi are slowly growing acquiredor congenital tumors with varied morphology,commonly encountered in dermatology clinics. Anytumor with rapid clinical growth must be assessedcarefully in order to exclude malignancy. We report awoman with a histopathologically benign intradermalnevus that presented as a rapidly evolving largecutaneous mass on the ear. Owing to the discrepancybetween the clinical and histopathological findings,an extensive histopathological work-up involvingmany deeper sections, immunohistochemical stains,and fluorescent in situ hybridization (FISH) analysiswas conducted in order to rule out malignancy.

Microcystic Adnexal Carcinoma of the scalp in an african-american male.

Microcystic adnexal carcinoma (MAC) is a rare adnexal neoplasm that typically presents in Caucasians. We report a rare case of MAC in a 68 year old African American male that presented as a large asymptomatic scalp mass. The clinical and histologic features of MAC are discussed. A summary of all reported cases of MAC in African American patients is presented, and treatment options are discussed.

Investigation of cAMP microdomains as a path to novel cancer diagnostics.

Understanding of cAMP signaling has greatly improved over the past decade. The advent of live cell imaging techniques and more specific pharmacologic modulators has led to an improved understanding of the intricacies by which cAMP is able to modulate such a wide variety of cellular pathways. It is now appreciated that cAMP is able to activate multiple effector proteins at distinct areas in the cell leading to the activation of very different downstream targets. The investigation of signaling proteins in cancer is a common route to the development of diagnostic tools, prognostic tools, and/or therapeutic targets, and in this review we highlight how investigation of cAMP signaling microdomains driven by the soluble adenylyl cyclase in different cancers has led to the development of a novel cancer biomarker. Antibodies directed against the soluble adenylyl cyclase (sAC) are highly specific markers for melanoma especially for lentigo maligna melanoma and are being described as "second generation" cancer diagnostics, which are diagnostics that determine the 'state' of a cell and not just identify the cell type. Due to the wide presence of cAMP signaling pathways in cancer, we predict that further investigation of both sAC and other cAMP microdomains will lead to additional cancer biomarkers. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.

Post-radiation atypical vascular proliferation on the head of a young woman: a diagnostic challenge.

With improved outcomes associated with radiotherapy (RT), post-irradiation tumors are increasingly seen in long-term cancer survivors. We report a case of a young woman who presented with a three-year history of a vascular lesion on the temple, previously irradiated for a childhood brain tumor. The history of radiation, the clinical appearance, and the biopsy findings of an atypical vascular proliferation in the dermis, were worrisome for a malignant vascular neoplasm and prompted surgical excision. However, further tissue analysis of the excised specimen confirmed a benign atypical vascular lesion (AVL) overlying a banal pilar cyst. Distinguishing post-radiation benign from malignant vascular lesions can be difficult because they share overlapping clinical and histopathologic features. Thus, any vascular lesion that occurs in a previously irradiated field should be excised completely with tumor-free margins and examined histologically.

Neighboring look-a-likes: distinguishing between breast and dermatologic lesions.

Due to the proximity of the skin, subcutis, and axilla to the breast, the possibility of a "breast mass" actually representing a dermatologic lesion should be considered, particularly if the proliferation does not look characteristically "mammary" in appearance. Even more underappreciated is the scenario of a dermatologic proliferation morphologically masquerading as a breast tumor. The pathologist can fall prey to this pitfall if he/she is led to believe that the location of the tumor is the breast proper. The aim of this review is to provide an overview of dermatologic mimickers of breast lesions and helpful ways to discern between them when possible.

Epidermotropic metastatic epithelioid sarcoma: a potential diagnostic pitfall.

Epithelioid sarcoma (ES) represents an aggressive soft tissue tumor with varied morphologic and histopathologic presentations that typically elicits a broad differential diagnosis, including granuloma annulare, necrobiotic granuloma, fibrous histiocytoma, synovial sarcoma, amelanotic melanoma and poorly differentiated primary cutaneous and metastatic adenocarcinoma. ES is characterized microscopically by a nodular arrangement of abundant, deeply eosinophilic, polygonal tumor cells with frequent central necrosis and hemorrhage, rare mitotic figures and minimal pleomorphism. At the periphery, tumor cells are spindle shaped and may exhibit frequent local infiltration along tendons, fascial planes and neurovascular bundles. Immunohistochemistry typically reveals expression of both epithelial and mesenchymal antigens, such as cytokeratin and vimentin, respectively. The absence of a connection between tumor cells and the overlying epidermis, with or without an in situ carcinoma component, typically rules out a primary cutaneous squamous cell carcinoma. We report a case of stage IV proximal-type ES that mimicked molluscum contagiosum clinically and was histopathologically reminiscent of invasive squamous cell carcinoma because of attachment and colonization of the overlying epidermis. The case represents an unusual pathologic presentation of ES and highlights potential pitfalls in establishing the diagnosis.

Hematopoietic transplant-associated thrombotic microangiopathy: case report and review of diagnosis and treatments.

Transplant-associated thrombotic microangiopathy (TA-TMA) refers to inflammatory and thrombotic diseases of the microvasculature characterized by hemolytic anemia, thrombocytopenia, and evidence of organ damage, particularly acute renal failure. This syndrome occurs in 10% to 20% of patients with allogeneic hematopoietic stem cell transplants (HSCTs). It is much less frequent in the autologous setting. TA-TMAs present diagnostic challenges because they may not clearly fall into one of the categories of the 2 major TMAs: atypical hemolytic uremic syndrome (aHUS) and thrombotic thrombocytopenic purpura (TTP). In addition, complications of the transplant itself, including infection, graft-versus-host disease, and disseminated intravascular coagulation, as well as the side effects of immunosuppressive drugs, can mimic a TMA. Because the pathophysiology of TA-TMA is poorly understood, current treatment options are suboptimal, and the condition carries a very high mortality rate. In 3 recent case summaries, the median acute response rate to plasma exchange was as high as 55%, but this therapy failed to alter underlying disease pathology and had little impact on overall mortality, which was approximately 80%. Indeed, the vast majority of TA-TMA patients lack suppression of ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) activity to less than 5% to 10% of normal and do not have a complete response to plasma exchange, characteristics indicating that a TTP-like disorder is not involved. Recent advances in the treatment of aHUS may offer a therapeutic option in the aHUS-like TMAs associated with HSCTs. These issues are discussed in the context of a patient recently evaluated and treated at our institution; the case serves to illustrate the difficulties associated with the diagnosis and treatment of TA-TMA.

Differential histone acetylation and super-enhancer regulation underlie melanoma cell dedifferentiation.

Dedifferentiation or phenotype switching refers to the transition from a proliferative to an invasive cellular state. We previously identified a 122-gene epigenetic gene signature that classifies primary melanomas as low versus high risk (denoted as Epgn1 or Epgn3). We found that the transcriptomes of the Epgn1 low-risk and Epgn3 high-risk cells are similar to the proliferative and invasive cellular states, respectively. These signatures were further validated in melanoma tumor samples. Examination of the chromatin landscape revealed differential H3K27 acetylation in the Epgn1 low-risk versus Epgn3 high-risk cell lines that corroborated with a differential super-enhancer and enhancer landscape. Melanocytic lineage genes (MITF, its targets and regulators) were associated with super-enhancers in the Epgn1 low-risk state, whereas invasiveness genes were linked with Epgn3 high-risk status. We identified the ITGA3 gene as marked by a super-enhancer element in the Epgn3 invasive cells. Silencing of ITGA3 enhanced invasiveness in both in vitro and in vivo systems, suggesting it as a negative regulator of invasion. In conclusion, we define chromatin landscape changes associated with Epgn1/Epgn3 and phenotype switching during early steps of melanoma progression that regulate transcriptional reprogramming. This super-enhancer and enhancer-driven epigenetic regulatory mechanism resulting in major changes in the transcriptome could be important in future therapeutic targeting efforts.

Agminated syringocystadenoma papilliferum: a new clinical presentation of a rare benign adnexal neoplasm.

Syringocystadenoma papilliferum is a rare adnexal tumor that often occurs as a solitary tumor in the head and neck region, although occurrences on other anatomical locations have been described. Linear configurations have been described, but an agminated form is a more rare and underreported variant of this tumor. We describe a case of a healthy 10-year old female with agminated syringocystadenoma papilliferum occurring on her left supraclavicular region, with the clinical appearance of grouped molluscum contagiosum papules.Case synopsis A healthy 10-year-old girl was referred for the treatment of a "collection of molluscum contagiosum" of the left supra clavicular region of several years duration. The lesions were asymptomatic and refractory to cryotherapy. The patient was a healthy girl with no significant systemic findings. Cutaneous exam revealed a clustered group of pink, dome shaped, umbilicated papules over a 1.5 x 1 cm area within the left supraclavicular fossa (Figure 1a). An excisional biopsy was performed. Routine H&E stained sections revealed cystic epidermal invaginations with papillary projections. The superficial portions of the cyst were lined by stratified keratinizing epithelium, whereas the deeper papillated portion exhibited a double layer of basal-like cells and luminal eosinophilic columnar cells with focal decapitation secretion. The papillary structures contained fibrovascular cores and lymphoplasmacytic infiltrates. A component of hamartomatous follicular growth was not identified (Figure 1b-d.). A diagnosis was made of agminated syringocystadenoma papilliferum.

B7-H3 drives immunosuppression and Co-targeting with CD47 is a new therapeutic strategy in ß-catenin activated melanomas.

In melanoma, immune cell infiltration into the tumor is associated with better patient outcomes and response to immunotherapy. T-cell non-inflamed tumors (cold tumors) are associated with tumor cell-intrinsic Wnt/ß-catenin activation, and are typically resistant to anti-PD-1 alone or in combination with anti-CTLA-4 therapy. Reversal of the 'cold tumor' phenotype and identifying new effective immunotherapies are challenges. We sought to investigate the role of a newer immunotherapy agent, B7-H3, in this setting. RNA sequencing was used to identify co-targeting strategies upon B7-H3 inhibition in a well-defined preclinical melanoma model driven by ß-catenin. We found that immune checkpoint molecule B7-H3 confers a suppressive tumor microenvironment by modulating antiviral signals and innate immunity. B7-H3 inhibition led to an inflamed microenvironment, up-regulation of CD47/SIRPa signaling, and together with blockade of the macrophage checkpoint CD47 resulted in additive antitumor responses. We found that the antitumor effects of the B7-H3/CD47 antibody combination were dependent on cytokine signaling pathways (CCR5/CCL5 and IL4).

Relapsing Helicobacter cinaedi Cellulitis without Bacteremia in a Patient with X-linked Agammaglobulinemia after 1 Year of Antibiotic Prophylaxis.

A 23-year-old man with Bruton's X-linked agammaglobulinemia (XLA), who required intravenous immunoglobulin G (IgG) every 3 weeks, presented with an erythematous scaly eruption adjacent to the chest port for antibiotic therapy (Figures 1A,B). His past medical history included Helicobacter cinaedi cellulitis in 2015 that was treated with intravenous vancomycin and ertapenem with no improvement after several months. The therapy was switched to ertapenem and amikacin, which was also unsuccessful after 1 year. Subsequently, on switching to oral doxycycline for 6 months, he had a 2-year period without skin lesions. He presented to Mount Sinai Hospital in 2019 with 2-day fever and newly appearing skin lesions. (SKINmed. 2022;20:457-459).

A nuclear cAMP microdomain suppresses tumor growth by Hippo pathway inactivation.

Cyclic AMP (cAMP) signaling is localized to multiple spatially distinct microdomains, but the role of cAMP microdomains in cancer cell biology is poorly understood. Here, we present a tunable genetic system that allows us to activate cAMP signaling in specific microdomains. We uncover a nuclear cAMP microdomain that activates a tumor-suppressive pathway in a broad range of cancers by inhibiting YAP, a key effector protein of the Hippo pathway, inside the nucleus. We show that nuclear cAMP induces a LATS-dependent pathway leading to phosphorylation of nuclear YAP solely at serine 397 and export of YAP from the nucleus with no change in YAP protein stability. Thus, nuclear cAMP inhibition of nuclear YAP is distinct from other known mechanisms of Hippo regulation. Pharmacologic targeting of specific cAMP microdomains remains an untapped therapeutic approach for cancer; thus, drugs directed at the nuclear cAMP microdomain may provide avenues for the treatment of cancer.