After a review of the physiology in the formation and degradation of cutaneous elastic tissue, we describe the clinicopathologic disorders characterized by increased and decreased cutaneous elastic tissue. Cutaneous disorders characterized by increased and/or abnormal elastic tissue in the dermis include elastoma, also named nevus elasticus, dermatosis lenticularis disseminata, pseudoxanthoma elasticum, late-onset focal dermal elastosis, linear focal elastosis, elastoderma, elastofibroma dorsi, and elastosis perforans serpiginosa. In some of these conditions, the specific histopathologic diagnosis may be rendered with hematoxylin-eosin stain, whereas in other ones special elastic tissue stains are necessary to demonstrate the anomalies. Cutaneous disorders characterized by decreased dermal elastic tissue include nevus anelasticus, papular elastorrhexis, perifollicular elastolysis, anetoderma cutis laxa, postinflammatory elastolysis and cutis laxa, white fibrous papulosis of the neck, pseudoxanthoma elasticum–like papillary dermal elastolysis, and mid dermal elastolysis. In most of these conditions, the histopathologic anomalies are only seen with elastic tissue stains, and cutaneous biopsies of these processes stained with hematoxylin-eosin show appearance of normal skin. The diagnosis of some of these disorders characterized by increased or decreased elastic dermal tissue should be followed by general exploration of the patient to rule out associated severe systemic anomalies, and in some cases, a genetic counseling should be offered to the family.

Atopic dermatitis (AD) is one of the most common chronic inflammatory skin diseases that affect both children and adults with a prevalence of 30% and 10%, respectively. Even though most of patients respond satisfactory to topical anti-inflammatory drugs, about 10% require one or more systemic treatments to achieve good control of their illness. The progressive and increasingly detailed knowledge in the immunopathogenesis of AD has allowed research on new therapeutic targets with very promising results in the field of biological therapy. In this article, we will review the different biological treatments with a focus on novel drugs. Their mechanism of action, current status and results from clinical trials and observational studies will be specified.

Osteonevus of Nanta is a rare histopathologic variant of melanocytic nevus that results from ossification of the dermis between dermal nests of melanocytes. Most cases described in the literature have been associated with long-standing intradermal nevi and were often located in the upper part of the body. We report a lesion on the shoulder of an elderly man showing the association of a common blue nevus and osteoma cutis, an exceptional feature which has been previously reported in 2 instances. We also describe for the first time the dermoscopic appearance of this "blue osteonevus."

Liposarcoma, usually arises in deep soft tissues and pleomorphic liposarcoma (PL), is the rarest histopathologic variant. However, 15 cases of entirely dermal PL have been reported. We describe a case of a 79-year-old man who developed a rapidly growing nodule on his thorax. Excisional biopsy was performed and immunohistochemical studies were carried. The lesion was a well-circumscribed dermal nodule composed of multivacuolated pleomorphic lipoblasts and atypical mitotic figures. Neoplastic cells expressed CD10 and resulted negative S100 protein, Melan-A, MITF-1, AE1/AE3, CD4, CD68 (PGM1), retinoblastoma gene family protein, pericentrine and lysozyme. Adipophilin stain showed the lipid contents in the cytoplasm of the neoplastic cells. MDM2 and CDK4 resulted both negative. A diagnosis of primary dermal PL was made. This case shows the utility of adipophilin immunostaining to prove the lipid contents in neoplastic cells, which has the advantage of using formalin-fixed paraffin-embedded tissue and making needless frozen sections and ultrastructural studies to show these findings. Negative MDM2/CDK4 staining in our case argues against the possibility of dedifferentiated liposarcoma and further supports the diagnosis of true PL.

Given the differences between patients with psoriasis alone or with psoriasis associated with PsA, patients with psoriasis and PsA should be followed and managed more closely and with specific attention.