A rare case of cutaneous interdigitating dendritic cell sarcoma.

Interdigitating dendritic cell sarcomas (IDCSs) are aggressive tumors of dendritic cells, often presenting with lymphadenopathy. Fewer than 10 cases of primary cutaneous IDCS have been reported. Histopathologically, IDCS presents as atypical spindle cells with irregular nuclei, and therefore can be difficult to distinguish from melanoma, follicular dendritic cell sarcoma, and Langerhans cell tumors by H&E examination alone. We report a unique case of a man with cutaneous IDCS that was initially misdiagnosed as melanoma. Having previously undergone an excision of a reported "melanoma" on the neck, he presented with a new growth on the cheek. Histopathologic findings revealed an atypical dermal lymphohistiocytic infiltrate around vessels and cells forming nests along the dermal-epidermal junction. Immunohistochemical stains were strongly positive for S100, fascin, and lysozyme; on the other hand, CD1a, langerin, CD21, CD23, and SOX10 were negative. These immunohistochemical findings were consistent with IDCS, and the patient's prior biopsy specimen was then revisited. Similar staining revealed that lesion also to be a cutaneous IDCS. Follow-up imaging with PET scan was negative for metastases, supporting the diagnosis of primary cutaneous IDCS. Our findings contribute to the limited literature on cutaneous IDCS and highlight a potential pitfall in its diagnosis because of overlapping histopathologic features with melanoma.

Atopic dermatitis in African American patients is TH2/TH22-skewed with TH1/TH17 attenuation.

BACKGROUND: African Americans (AA) are disproportionately impacted by atopic dermatitis (AD), with increased prevalence and therapeutic challenges unique to this population. Molecular profiling data informing development of targeted therapeutics for AD are derived primarily from European American (EA) patients. These studies are absent in AA, hindering development of effective treatments for this population. OBJECTIVE: We sought to characterize the global molecular profile of AD in the skin of AA patients as compared with that of EA AD and healthy controls. METHODS: We performed RNA-Seq with reverse transcription polymerase chain reaction validation and immunohistochemistry studies in lesional and nonlesional skin of AA and EA AD patients vs healthy controls. RESULTS: African American AD lesions were characterized by greater infiltration of dendritic cells (DCs) marked by the high-affinity immunoglobulin E (IgE) receptor (FcεR1+) compared with EA AD (P < .05). Both AD cohorts showed similarly robust up-regulation of Th2-related (CCL17/18/26) and Th22-related markers (interleukin [IL]-22, S100A8/9/12), but AA AD featured decreased expression of innate immune (tumor necrosis factor [TNF], IL-1ß), Th1-related (interferon gamma [IFN-γ], MX1, IL-12RB1), and Th17-related markers (IL-23p19, IL-36G, CXCL1) vs EA AD (P < .05). The Th2 (IL-13) and Th22-related products (IL-22, S100A8/9/12) and serum IgE were significantly correlated with clinical severity (Scoring of Atopic Dermatitis [SCORAD]) in AA. Fillagrin (FLG) was exclusively down-regulated in EA AD, whereas loricrin (LOR) was down-regulated in both AD cohorts and negatively correlated with SCORAD in AA. CONCLUSION: The molecular phenotype of AA AD skin is characterized by attenuated Th1 and Th17 but similar Th2/Th22-skewing to EA AD. Our data encourages a personalized medicine approach accounting for phenotype-specific characteristics in future development of targeted therapeutics and clinical trial design for AD.

Energy-Based Devices for the Treatment of Facial Skin Conditions in Skin of Color.

Background: The development of microfocused ultrasound and fractional radiofrequency-based devices has expanded the range of cosmetic treatment options for patients with skin of color. Fractional non-ablative laser treatments can also be safely performed in skin types III-VI with appropriate settings and adjunctive topical treatments. Objective: We sought to review the available literature on the use of energy-based devices for treatment of facial skin conditions in skin types III-VI. Methods: A PubMed search was performed on studies from 2010-2021 assessing safety and efficacy of fractional ablative and non-ablative lasers, radiofrequency, and microfocused ultrasound-based treatments for conditions such as acne scars, melasma, benign pigmented lesions, rhytids, and skin laxity in skin types III-VI. Results: Seven randomized trials, fourteen prospective cohort studies, and six retrospective reviews were included. Combination treatment with fractional radiofrequency and non-ablative laser has demonstrated efficacy in the treatment of acne scars in skin of color with minimal adverse effects. Laser-assisted drug delivery with low-density 1927-nm thulium or diode lasers has been shown to reduce the number of treatments required for significant clearance of melasma as compared with other modalities. Microfocused ultrasound has been shown to safely treat skin laxity in skin of color. Limitations: There is a paucity of studies which include patients with skin type VI, limiting our overall understanding of the safety of these treatments in skin of color. Conclusion: There are numerous available studies demonstrating safety and efficacy of energy-based devices for the treatment of facial skin conditions in skin types III-VI, but the significant variation among their designs, methods of assessment, and study populations highlights the need for larger meta-analyses to further interpret their results.

Unilateral Verrucous Psoriasis.

Verrucous psoriasis is a variant of psoriasis that presents with wartlike clinical features and overlapping histologic features of verruca and psoriasis. The disease typically arises in patients with established psoriasis but can occur de novo. We report the case of an 80-year-old man with a history of hypertension and coronary artery disease who presented with a rash characterized by multiple asymptomatic plaques with overlying verrucous nodules on the left side of the body. The lesions appeared shortly after coronary artery bypass surgery with a saphenous vein graft.