Search

Acral melanoma (AM) is a subtype of cutaneous melanoma located on the palms, soles, and nails. The pathogenesis of AM involves mechanical stimulation and characteristic tumor-promoting mutations, such as those in the KIT proto-oncogene. Dermoscopy is useful for diagnosing AM, which is characterized by parallel ridge patterns and irregular diffuse pigmentation. Although histopathological confirmation is the gold standard for diagnosing AM, lesions showing minimal histopathological changes should be considered early-stage AM if they clinically resemble it. Recently, immunohistochemical staining of preferentially expressed antigen in melanoma has been recognized as a useful method to distinguish benign from malignant melanocytic tumors. Research reveals that AM is associated with an immunosuppressive microenvironment characterized by increased numbers of M2 macrophages and regulatory T cells, alongside a decreased number of tumor-infiltrating lymphocytes. Mohs micrographic surgery or digit-sparing wide local excision has been explored to improve quality of life and replace wide local excision or proximal amputation. AM has a worse prognosis than other subtypes, even in the early stages, indicating its inherent aggressiveness. [ABSTRACT FROM AUTHOR]

Background Amelanotic acral melanoma (AAM) is a rare type of acral melanoma that has a poor prognosis. Objectives To investigate the transcriptomic differences between AAM and pigmented acral melanoma (PAM). Methods Differences in the spatially resolved transcriptomic profiles of 9 patients with AAM with 29 regions of interest (ROIs) and 11 patients with PAM with 46 ROIs were investigated using S100b and CD3 morphology markers. Results In S100b+ tumour cell areas, we detected 11 upregulated differentially expressed genes (DEGs; including chaperone/ubiquitin--associated DEGs) and 82 downregulated DEGs (including human leucocyte antigen) in AAMs vs. PAMs. Protein–protein interaction network and pathway analyses revealed significant enrichment of dysregulated translational and nonsense-mediated decay pathways but significant decreases in antigen processing and presentation, interferon signalling and melanin biosynthesis pathways in S100b+ ROIs of AAMs compared with PAMs. In tumour-associated immune cell areas, the numbers of CD8 T cells (P = 0.04) and M1 macrophages (P = 0.01) were significantly decreased, whereas those of monocytes (P = 0.04) and endothelial cells (P = 0.04) were increased in AAMs compared with PAMs. Conclusions These findings could widen our understanding of the biological differences between AAMs and PAMs, which might result in a different clinical course. [ABSTRACT FROM AUTHOR]

Distant metastasis, the leading cause of cancer death, is efficiently kept in check by immune surveillance. Studies have uncovered peripheral natural killer (NK) cells as key antimetastatic effectors and their dysregulation during metastasis. However, the molecular mechanism governing NK cell dysfunction links to metastasis remains elusive. Herein, MAP4K1 encoding HPK1 is aberrantly overexpressed in dysfunctional NK cells in the periphery and the metastatic site. Conditional HPK1 overexpression in NK cells suffices to exacerbate melanoma lung metastasis but not primary tumor growth. Conversely, MAP4K1‐deficient mice are resistant to metastasis and further protected by combined immune‐checkpoint inhibitors. Mechanistically, HPK1 restrains NK cell cytotoxicity and expansion via activating receptors. Likewise, HPK1 limits human NK cell activation and associates with melanoma NK cell dysfunction couples to TGF‐β1 and patient response to immune checkpoint therapy. Thus, HPK1 is an intracellular checkpoint controlling NK‐target cell responses, which is dysregulated and hijacked by tumors during metastatic progression. [ABSTRACT FROM AUTHOR]

Background: Studies on the interaction between tumour‐infiltrating immune cells (TIICs) and tumour cells in melanoma arising from congenital melanocytic nevus (CMN) are lacking. Objective: The aim of this study was to determine the intratumoral immune landscape of TIICs and tumour cells during invasion and metastasis. Methods: Tissue specimens were obtained from patients with melanoma originating from CMN. Differential gene expression in melanoma cells and TIICs during invasion and metastasis was determined using spatial transcriptomics. Results: As invasion depth increased, the expression of LGALS3, known to induce tumour‐driven immunosuppression, increased in melanoma cells. In T cells, the expression of genes that inhibit T‐cell activation increased with increasing invasion depth. In macrophages, the expression of genes related to the anti‐inflammatory M2 phenotype was upregulated with increasing invasion depth. Compared to primary tumour cells, melanoma cells in metastatic lesions showed upregulated expression of genes associated with cancer immune evasion, including AXL and EPHA2, which impede T‐cell recruitment, and BST2, associated with M2 polarization. Furthermore, T cells showed increased expression of genes related to immunosuppression, and macrophages exhibited increased expression of genes associated with the M2 phenotype. Conclusions: The interaction between melanomas arising from CMN and TIICs may be important for tumour progression and metastasis. [ABSTRACT FROM AUTHOR]

The morphology of facial scars shows a wide variation in terms of texture and colour. To date, there are no reliable predictors of aberrant scarring. We conducted a retrospective analysis to identify factors associated with specific scar features and types. Photographs and medical records of 428 patients with facial scars were retrospectively reviewed. Patients with keloids were excluded. The mean age of the patients was 45.43 ± 23.13 years with a male‐to‐female ratio of 1:1.36. Atrophic scars were the most common (42.8%), followed by flat scars (38.7%) and hypertrophic scars (18.5%). Scars on the forehead were more likely to be atrophic, whereas scars on the chin/jaw and around the mouth were more likely to be hypertrophic. Hypopigmentation was significantly more common in scars located on the forehead. Redness (erythema) was significantly more common in scars located on the chin/jaw. Old scars were less likely to be erythematous, and hypertrophic. Atrophic scars were more common in younger patients. Scars caused by dermatologic conditions, such as acne, were more likely to be atrophic, whereas surgical scars had the lowest risk of being atrophic or hypertrophic. In conclusion, the location, onset, and cause of facial scars were associated with specific features of scars. [ABSTRACT FROM AUTHOR]

Lymphoplasmacytic lymphoma (LPL) is a rare variant of non‐Hodgkin lymphoma, accounting for <1% of cases. Skin involvement in LPL is quite rare—accounting for approximately 5% of extramedullary disease—and includes a variety of clinical morphologies, such as erythematous‐to‐violaceous plaques, violaceous nodules or tumors, and ulceration at various anatomical sites. Herein, we report the case of a 45‐year‐old Korean woman who presented with generalized erythematous indurated plaques and pendulous skin growths, which were asymptomatic, with marked diffuse infiltration of lymphocytes and plasma cells in the dermis. Immunohistochemical studies revealed that the lymphoid cells expressed CD3, CD79a, and cytoplasmic IgG, but lacked CD10 and IgM. Moreover, kappa light chain restriction and monoclonal immunoglobulin heavy chain gene rearrangement were observed. Upon further workup, lymphoma involvement was reported in multiple lymph nodes, including those in the cervical and axillary regions. This case shows a unique form of cutaneous LPL clinically presenting as acquired cutis laxa, emphasizing the dermatologists' need to be vigilant for variant forms of this disease. [ABSTRACT FROM AUTHOR]

This article presents a study on psoriasiform mycosis fungoides (MF), a subtype of cutaneous T-cell lymphoma. The study found that psoriasiform MF is associated with specific clinical features, such as head and neck involvement, lymph node involvement, and advanced stages of the disease. Psoriasiform MF also had poorer survival outcomes compared to other subtypes of MF. The study suggests that psoriasiform MF may have a more rapid clinical progression and highlights the importance of recognizing and diagnosing this subtype accurately. The study was supported by funding from the Asan Cancer Institute and the National Research Foundation of Korea. [Extracted from the article]

Background: Limited clinicopathological and prognostic data are available on hydroa vacciniforme (HV)-like lymphoproliferative diseases (HVLPD). Methods: This systematic review searched HVLPD reports in Medline via PubMed, Embase, Cochrane, and CINAHL databases in October 2020. Results: A total of 393 patients (65 classic HV, 328 severe HV/HV-like T-cell lymphoma [HVLL]) were analyzed. Among severe HV/HVLL cases, 56.0% were Asians, whereas 3.1% were Caucasians. Facial edema, hypersensitivity to mosquito bites, the onset of skin lesion, and percentage of severe HV/HVLL differed significantly by race. Progression to systemic lymphoma was confirmed in 9.4% of HVLPD patients. Death occurred in 39.7% patients with severe HV/HVLL. Facial edema was the only risk factor associated with progression and overall survival. Mortality risk was higher in Latin Americans than in Asians and Caucasians. CD4/CD8 double-negativity was significantly associated with the worst prognosis and increased mortality. Conclusion: HVLPD is a heterogeneous entity with variable clinicopathological features associated with genetic predispositions. [ABSTRACT FROM AUTHOR]