Caroline Wilkel

Localized Darier's disease in a Blaschkoid distribution: Two cases of phenotypic mosaicism and a review of mosaic Darier's disease

Dariers disease is a rare autosomal dominant genodermatosis. Characteristic skin and nail changes consist of bilateral crusted red‐brown papules and plaques in a seborrheic distribution, and V‐shaped nicking or longitudinal ridging of the nails. In limited cases, a segmental distribution of this disease may be present in which localized lesions, found along the lines of Blaschko, are otherwise indistinguishable from those of generalized Dariers disease. Genomic mosaicism in localized lesions of Dariers disease is a new concept that was recently demonstrated in individuals of mosaic phenotypes. Both type 1 and type 2 mosaic phenotypes have been reported. We report two cases of type 1 localized Dariers disease in a Blaschkoid distribution and review the genetic implications of phenotypic mosaicism within the field of Dariers disease.

Xylene substitutes in frozen sections.

BACKGROUND Toxic exposure to xylene may occur during routine histopathologic staining procedures. Safer xylene substitutes have been available for over a decade, however, a 1991 survey of 25 Mohs training programs revealed that only 56% were using xylene substitutes. OBJECTIVE The purpose of this study was to compare xylene to xylene substitutes in the histologic preparation of frozen sections with respect to staining quality, clarity, cellular detail, and tissue distortion. METHODS Xylene and xylene substitutes were used as the final clearing agent in the routine histologic preparation of fresh frozen horizontal sections. The slides were evaluated by a dermatopathologist and a Mohs surgeon in a blinded manner. RESULTS No difference between xylene and the xylene substitutes were noted. CONCLUSION In light of the improved safety profile and efficacy of the xylene substitutes, they should replace xylene in the Molis laboratory.

Interrater reliability for histopathologic diagnosis of keratinocyte carcinomas

therapy in a patient with metastatic cutaneous squamous cell carcinoma. Blockade of CTLA-4 and PD-1 increases the activation of T cells, not only against malignant cells, but also other cells expressing foreign antigens such as kidney allograft donor antigens. One renal OTR with BRAF V600Eemutated melanoma progressed on dual kinase treatment and single agent antiePD-1 ( pembrolizumab) and is currently being treated with nivolumab and talimogene laherparepvec (a herpes simplex type 1ederived oncolytic intralesional immunotherapy) to subcutaneous metastases. Talimogene laherparepvec has not previously been reported among OTRs as a single agent therapy or in conjunction with checkpoint inhibitors. In summary, the use of checkpoint inhibitors in OTRswithmetastaticmelanomashouldbeconsidered (Table II). However, special considerations should be given for the use of checkpoint inhibitors in patients with certain types of transplanted organs (such as liver) because of the potential for graft rejection. We alsopropose thatmultiple institutions report theuse of these agents; this practice would be more effective at determining the drug efficacy and risk among OTRs.