No abstract

Reticular erythematous mucinosis (REM) is a rare cutaneous condition often referred to as plaque-like mucinosis and midline mucinosis. Although the exact etiology remains undefined, efforts to elucidate pathogenesis, disease associations, and prospective treatment modalities have been encouraging. Induction of the disease has been associated with viral processes, solar irradiation, specific cell lines, and cytokines such as Interleukin (IL)-1β. Clinically, patients typically develop erythematous macules and papules that coalesce into reticulated patterns on the midline of the chest or back. The lesions have a tendency to respond to systemic antimalarial therapy, but novel therapeutic approaches with ultraviolet A1 light (UVA1) and pulse dye laser (PDL) have been promising. Histologically, REM is associated with a mild, predominantly lymphocytic infiltrate with variable deep perivascular extension. Mucin may be seen in the upper and mid dermis and is prominent around the infiltrate and appendages. IgM deposits may be visualized under direct immunoflourescence along the basal layer. Because of the similarities between REM and tumid lupus, the two disease processes have often been grouped together. The remarkable overlap between the two diseases suggests that the two conditions may actually be the same disease.

Basal cell carcinoma (BCC) remains the most common form of nonmelanoma skin cancer (NMSC) in Caucasians, with perhaps as many as 2 million new cases expected to occur in the United States in 2010. Many treatment options, including surgical interventions and nonsurgical alternatives, have been utilized to treat BCC. In this paper, two non-surgical options, imiquimod therapy and photodynamic therapy (PDT), will be discussed. Both modalities have demonstrated acceptable disease control rates, cosmetically superior outcomes, and short-term cost-effectiveness. Further studies evaluating long-term cure rates and long-term cost effectiveness of imiquimod therapy and PDT are needed.

Mohs micrographic surgery (MMS) has increasingly become an accepted therapy for melanoma in situ on chronically sun damaged skin (CSDS). However, melanocytes are difficult to locate in frozen material on hematoxylin and eosin. In addition, determining the cut-off between the melanoma and the "atypical melanocytic hyperplasia" in CSDS can be challenging in frozen or formalin-fixed paraffin-embedded sections, with or without immunohistochemistry (IHC). In this article, we report the use of a rapid, 35-minute protocol using microphthalmia-associated transcription factor (MITF) IHC for identifying melanocytes in frozen tissue for its potential use in MMS. In contrast to melanoma antigen recognized by T cells (MART-1), MITF is a nuclear stain, which simplifies identification of melanocytes and quantification of melanocytic parameters. In this study, MITF IHC in frozen sections yielded equivalent melanocyte nuclear diameter and density measurements compared with formalin-fixed paraffin-embedded sections. Nuclear diameter measurements obtained with MITF were similar to that previously reported with MART-1, but the melanocyte density figures were lower. Reliable labeling of melanocytes in frozen sections required the use of diaminobenzidine (DAB) chromogen with Giemsa counterstaining and a buffer devoid of surfactant. Our experience with MITF IHC indicates that it is a dependable immunostain in frozen sections, and may prove to be useful in MMS as an adjunct to hematoxylin and eosin and MART-1 IHC for interpretation of margins for melanoma in situ on CSDS.