PD-L1 expression in the tumor immune microenvironment is recognized as both a prognostic and predictive biomarker in patients with cutaneous melanoma, a finding closely related to its adaptive (IFN-γ-mediated) mechanism of expression. Approximately 35% of cutaneous melanomas express PD-L1, however, the expression patterns, levels, and prevalence in rarer melanoma subtypes are not well described. We performed immunohistochemistry for PD-L1 and CD8 on 200 formalin-fixed paraffin-embedded specimens from patients with acral (n = 16), mucosal (n = 36), uveal (n = 103), and chronic sun-damaged (CSD) (n = 45) melanomas (24 lentigo maligna, 13 ‘mixed’ desmoplastic, and 8 ‘pure’ desmoplastic melanomas). CD8+ tumor-infiltrating lymphocyte (TIL) densities were characterized as mild, moderate, or severe, and their geographic association with PD-L1 expression was evaluated. Discrete lymphoid aggregates, the presence of a spindle cell morphology, and the relationship of these features with PD-L1 expression were assessed. PD-L1 expression was observed in 31% of acral melanomas, 44% of mucosal melanomas, 10% of uveal melanomas, and 62% of CSD melanomas (P<0.0001). Compared to our previously characterized cohort of cutaneous melanomas, the proportion of PD-L1(+) tumors was lower in uveal (P = 0.0002) and higher in CSD (P = 0.0073) melanomas, while PD-L1 expression in the acral and mucosal subtypes was on par. PD-L1 expression in all subtypes correlated with a moderate–severe grade of CD8+ TIL (all, P<0.003), supporting an adaptive mechanism of expression induced during the host antitumor response. The tumor microenvironments observed in CSD melanomas segregated by whether they were the pure desmoplastic subtype, which showed lower levels of PD-L1 expression when compared to other CSD melanomas (P = 0.047). The presence of lymphoid aggregates was not associated with the level of PD-L1 expression, while PD-L1(+) cases with spindle cell morphology demonstrated higher levels of PD-L1 than those with a nested phenotype (P<0.0001). Our findings may underpin the reported clinical response rates for anti-PD-1 monotherapy, which vary by subtype.

Background A pterygium is a fleshy, wing-shaped growth from the conjunctiva, crossing over the limbus onto the cornea. Prevalence ranges widely around the world. Evidence suggests that ultraviolet light is a major contributor in the formation of pterygia. Pterygia impair vision, limit eye movements, and can cause eye irritation, foreign body sensation, and dryness. In some susceptible patients, the pterygium can grow over the entire corneal surface, blocking the visual axis. Surgery is the only effective treatment for pterygium, though recurrences are common. With simple excision techniques (that is, excising the pterygium and leaving bare sclera), the risk of recurrence has been reported to be upwards of 80%. Pterygium excision combined with a tissue graft has a lower risk of recurrence. In conjunctival autograft surgery, conjunctival tissue from another part of the person’s eye along with limbal tissue is resected in one piece and used to cover the area from which the pterygium was excised. Another type of tissue graft surgery for pterygium is amniotic membrane graft, whereby a piece of donor amniotic membrane is fixed to the remaining limbus and bare sclera area after the pterygium has been excised. Objectives The objective of this review was to assess the safety and effectiveness of conjunctival autograft (with or without adjunctive therapy) compared with amniotic membrane graft (with or without adjunctive therapy) for pterygium. We also planned to determine whether use of MMC yielded better surgical results and to assess the direct and indirect comparative costs of these procedures. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (Issue 10, 2015), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2015), EMBASE (January 1980 to November 2015), PubMed (1948 to November 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to November 2015), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) (last searched 21 November 2014), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 23 November 2015. Selection criteria We included in this review randomized controlled trials that had compared conjunctival autograft surgery (with or without adjunctive therapy) with amniotic membrane graft surgery (with or without adjunctive therapy) in people with primary or recurrent pterygium. Data collection and analysis Two review authors independently screened search results and assessed full-text reports from among the potentially eligible trials. Two review authors independently extracted data from the included trials and assessed the trial characteristics and risk of bias. The primary outco...