Can PRAME immunohistochemistry be used to differentiate sebaceous carcinoma from basal cell carcinoma?

The histopathology of sebaceous carcinoma (SBC) can mimic other skin neoplasms, including basal cell carcinoma (BCC).Therefore, diagnostic biomarkers are needed for a subset of cases. Normal sebaceous glands express PRAME (PRAME nuclearreceptor transcriptional regulator), a melanoma-associated biomarker.Donell et al. showed that PRAME has strong immunoreactivity with basaloid sebocytes in SBC. Ng et al. reported patchy cytoplasmic staining in the germinative sebocytes only.Sebaceous glands (H&E stain and PRAME stain)Objective: to evaluate the utility of PRAME immunohistochemistry as a diagnostic biomarker for SBC and its usefulness in the distinction of SBC from BCC

The Free Sign in morphea and other sclerosing disorders: A clue to the presence of early sclerosis?

BackgroundThe Floating Sign is a histopathologic clue to the diagnosis of autoimmune sclerosing skin disorders such as morphea and interstitial granulomatous dermatitis (IGD). On the other hand, the "free-floating" sign has been associated with neoplasms, for example, dermatofibroma and interstitial mycosis fungoides. Herein, we report the Free Sign in sclerosing skin disorders.MethodsIn a case-control study, we applied detailed histopathologic definitions of Floating Sign and Free Sign to assess their presence in morphea, IGD, and other sclerosing disorders.ResultsFree Sign was present in most cases of morphea (46/55, 84%) and IGD (7/13, 54%) but not necrobiosis lipoidica (NL) (6/14, 42.8%) or sclerodermoid graft versus host disease (SGVHD) (2/7, 28.5%). The sensitivity and specificity of Free Sign for morphea versus other disorders was 84% and 56%, respectively. Floating Sign was not identified in most cases: NL (3/14, 21.4%), SGVHD (1/7, 14.2%), morphea (5/55, 9%), IGD (1/13, 7.7%). The diagnostic sensitivity of Floating Sign in morphea was 9%.ConclusionsThe Free Sign was present in most cases of morphea in our series and may represent a clue to the presence of evolving sclerosis. Free Sign may be seen in other sclerosing disorders. Technical artifact is a potential cause of a false-positive Free Sign

White hair in alopecia areata: Clinical forms and proposed physiopathological mechanisms

Alopecia areata is a common form of non-scaring type of hair loss. It is believed to be a consequence of an immune-mediated stimulus, probably involving autoreactive T-cells against antigens present in the hair follicle. The exact antigen is still unknown; however, some authors have proposed that melanogenesis-associated molecules might trigger autoimmunity. Although transient white hair regrowth is a common and well-known situation in alopecia areata, there are other different types of white hair phenomena in this context; including permanent white hair regrowth, spearing of white hair in a patchy pattern or spearing in a diffuse form giving the appearance of the so-called “overnight graying phenomena” or Canitis subita. In this review we aim to describe the different clinical aspects of white hair in alopecia areata as well as the proposed pathophysiological mechanisms involved in this phenomena. •White hair phenomena in alopecia areata most commonly can be observed transiently during the regrowing phase, but rare cases can become permanent. Additionally, it can be a manifestation of a diffuse form of AA, called Canities subita, in which pigmented hairs are the main target. Dermatologist should have in mind this uncommon phenomena in the approach of a patient with hair whitening