Melanoma is the most severe type of skin cancer and its incidence has increased in the last decades. In the United States, it is the 6th most common cancer in both men and women. Prognosis for patients with melanoma depends on the stage of the disease at the time of diagnosis and it can be influenced by the immunologic response. Melanoma has been historically considered an immunogenic malignancy. It often contains great amount of immune cells (different subsets of T-cells, dendritic cells, macrophages, neutrophils, mast cells, B lymphocytes), which may reflect a continuous intercommunication between host and tumor. It is not established if tumor-infiltrating lymphocytes (TILs) are induced by tumor cells or by other components of the microenvironment or when they are a host direct immunologic reaction. It has been observed that in many cases, the presence of a dense TIL is associated with good prognosis. The pattern and activation state of the cells which constitute TIL is variable and modulates the clinical outcome. An important step in the understanding of tumor immunobiology is the analysis of the populations and subsets of immune cells that form TIL. Besides its prognostic significance, after approval of cytotoxic T lymphocyte antigen 4, programmed cell death-1 and programmed death-1 ligand antibodies for the treatment of melanoma, the assessment of immune infiltrate composition has become even more captivating, as it could provide new target molecules and new biomarkers for predicting the effect of the treatment and disease outcome in patients treated with immunotherapy. In this review we discuss current state of knowledge in the field of immune cells that infiltrate melanoma, resuming the potential of TIL components to become prognostic markers for natural evolution, for response to drugs or valuable targets for new medication.

Epithelial-mesenchymal transition (EMT) is involved in physiologic processes such as embryogenesis and wound healing. A similar mechanism occurs in some tumors where cells leave the epithelial layer and gain mesenchymal particularities in order to easily migrate to other tissues. This process can explain the invasiveness and aggressiveness of these tumors which metastasize, by losing the epithelial phenotype (loss of E-cadherin, desmoplakin, and laminin-1) and acquiring mesenchymal markers (N-cadherin). Complex changes and interactions happen between the tumor cells and the microenvironment involving different pathways, transcription factors, altered expression of adhesion molecules, reorganization of cytoskeletal proteins, production of ECM-degrading enzymes, and changes in specific microRNAs. The purpose of this review is to determine particularities of the EMT process in the most common malignant cutaneous tumors (squamous cell carcinoma, basal cell carcinoma, and melanoma) which still have an increasingly high incidence. More studies are required on this topic in order to establish clear correlations. High costs related to skin cancer therapies in general as well as high impact on patients’ quality of life demand finding new, reliable prognostic and therapeutic markers with significant public health impact.

Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a glycoprotein belonging to the carcinoembryonic antigen (CEA) family that is expressed on a wide variety of cells and holds a complex role in inflammation through its alternate splicing and generation of various isoforms, mediating intricate mechanisms of modulation and dysregulation. Initially regarded as a tumor suppressor as its expression shows considerable downregulation within the epithelia in the early phases of many solid cancers, CEACAM1 has been linked lately to the progression of malignancy and metastatic spread as various papers point to its role in tumor progression, angiogenesis, and invasion. We reviewed the literature and discussed the various expression patterns of CEACAM1 in different types of tumors, describing its structure and general biologic functions and emphasizing the most significant findings that link this molecule to poor prognosis. The importance of understanding the role of CEACAM1 in cell transformation stands not only in this adhesion molecule's value as a prognostic factor but also in its promising premise as a potential new molecular target that could be exploited as a specific cancer therapy.

Methotrexate (MTX) is a folic acid analog with anti-proliferative (anti-neoplastic, cytotoxic), immunosuppressive and anti-inflammatory properties, which has been used in the treatment of various cutaneous disorders, such as psoriasis, keratoacanthoma, pityriasis rubra pilaris, atopic dermatitis, mycosis fungoides, bullous skin diseases, systemic sclerosis, morphea, lupus erythematosus, dermatomyositis and crusted scabies. Inhibition of cell proliferation is explained through its role in blocking DNA/RNA synthesis, by inhibiting dihydrofolate reductase, necessary for the production of pyrimidine and purine nucleotides. An anticancer effect can be related to α-oxoaldehyde metabolism (MTX increases methylglyoxal levels). Its anti-inflammatory property is based on the inhibition of 5-aminoimidazole-4-carboxamide ribonucleotide transformylase, thus increasing intracellular and extracellular adenosine, a purine nucleoside with anti-inflammatory effect. This drug can limit inflammation by scavenging free radicals and decreasing malondialdehyde-acetaldehyde protein-adduct production. Moreover, the anti-proliferative and anti-inflammatory effects can also be related to inhibition of the DNA methylation pathway, thus inhibiting methionine formation. The aim of the present study was to report various dermatological cases from our daily practice that demonstrate the efficacy of MTX in the treatment of cutaneous diseases, highlighting different mechanisms of action: its anti-inflammatory effect in psoriasis and its anti-proliferative, and anti-neoplastic effect in well-differentiated squamous cell carcinoma or in keratoacanthoma. Moreover, different administration pathways and doses are addressed. Assessment of the treatment plan, clinical improvement of cutaneous lesions, biologic evaluation, final aesthetic result, quality of life, as well as potential adverse effects and drug tolerance related to each case mentioned.

Halo nevi, known as leukoderma acquisitum centrifugum, Sutton nevus, leukopigmentary nevus, perinevoid vitiligo, or perinevoid leukoderma, together with vitiligo and melanoma-associated hypopigmentation, belong to the group of dermatoses designated as immunological leukodermas. The etiology and pathogenesis of halo nevi has not been fully elucidated. There are several mechanisms through which a lymphocytic infiltrate can induce tumoral regression. In this review, we aimed to update the knowledge about Sutton nevi starting with the clinical appearance and dermoscopic features, continuing with information regarding conventional microscopy, immunohistochemistry, and the immunological mechanisms responsible for the occurrence of halo nevi. We also included in the article original unpublished results when discussing dermoscopic, pathologic and immunohistochemical results in halo nevi. Sutton nevi are valuable models for studying antitumor reactions that the human body can generate. The slow and effective mechanism against a melanocytic skin tumor can teach us important lessons about both autoimmune diseases and anticancer defenses.