Immunohistochemical Similarities between Lichen Sclerosus et Atrophicus and Morphea: A Case Study

Periostin in the pathogenesis of skin diseases

Skin is an organ that is susceptible to damage by external injury, chronic inflammation, and autoimmunity. Tissue damage causes alterations in both the configuration and type of cells in lesional skin. This phenomenon, called tissue remodeling, is a universal biological response elicited by programmed cell death, inflammation, immune disorders, and tumorigenic, tumor proliferative, and cytoreductive activity. In this process, changes in the components of the extracellular matrix are required to provide an environment that facilitates tissue remodeling. Among these extracellular matrix components, periostin, a glycoprotein that is predominantly secreted from dermal fibroblasts, has attracted attention. Periostin localizes in the papillary dermis of normal skin, and is aberrantly expressed in the dermis of lesional skin in atopic dermatitis, scar, systemic/limited scleroderma, melanoma, cutaneous T cell lymphoma, and skin damage caused by allergic/autoimmune responses. Periostin induces processes that result in the development of dermal fibrosis, and activate or protract the immune response. The aim of this review was to summarize recent knowledge of the role of periostin in the pathogenesis of dermatoses, and to explore whether periostin is a potential therapeutic target for skin diseases.

Plexiform Fibrohistiocytic Tumor on the Ear: Case Report and Immunohistochemical Investigation of Stromal Factor

Plexiform fibrohistiocytic tumor (PFT) is a rare mesenchymal neoplasm of intermediate malignant potential with a high local recurrence rate. In this report, we describe a case of PFT on the ear, which showed a dense deposition of periostin (POSTN) in the stromal areas of the tumor. In addition, dense infiltration of CD163+CD206– tumor-associated macrophages (TAMs) was detected in the same areas as POSTN. Since POSTN was previously reported to possess immunomodulatory effects on TAMs, our present report suggested the significance of the POSTN/TAMs axis in the progression of PFT.

Adult-onset acquired partial lipodystrophy accompanied by rheumatoid arthritis

Lipodystrophy is a group of metabolic disorders, possibly caused by autoimmune disease. In this report, we describe a case of adult-onset acquired partial lipodystrophy accompanied by rheumatoid arthritis without a family history. Interestingly, immunohistochemical staining revealed dense infiltration of IL-27-producing cells as well as MMP-7-and MMP-28-expressing cells, both of which have been reported to facilitate the development of autoimmune disease. Our present case might suggest possible mechanisms for acquired partial lipodystrophy.