KIT mutations and CD117 overexpression are markers of better progression-free survival in vulvar melanomas

BACKGROUND

Few studies have addressed prognostic markers and none has correlated molecular status and prognosis in vulvar melanomas.

OBJECTIVES

To evaluate the clinicopathological features of 95 cases of vulvar melanoma.

METHODS

p53, CD117, Ki-67, neurofibromin, brafv600e and nrasq61r immunostains, and molecular analyses by either targeted next-generation or direct sequencing, were performed on available archival materials.

RESULTS

Molecular testing detected mutations in KIT (44%), BRAF (25%), NF1 (22%), TP53 (17%), NRAS (9%) and TERT promoter (9%). Co-mutation of KIT and NF1 and of KIT and NRAS were identified in two and one cases, respectively. KIT mutations were significantly associated with better progression-free survival in univariate analyses. In multivariate analyses CD117 expression was significantly associated with better progression-free survival. Tumour thickness was significantly associated with worse progression-free and overall survival, and perineural invasion significantly correlated with reduced melanoma-specific survival and reduced overall survival. Cases were from multiple centres and only a subset of samples was available for molecular testing.

CONCLUSIONS

KIT mutations and CD117 overexpression are markers of better progression-free survival. In addition to its prognostic value, molecular testing may identify cases that might respond to targeted agents or immunotherapeutic approaches.

Over-expression of p45(SKP2) in Kaposi's sarcoma correlates with higher tumor stage and extracutaneous involvement but is not directly related to p27(KIP1) down-regulation

F-Box protein p45(SKP2) is the substrate-specific receptor of ubiquitin-protein ligase SCF/p45(SKP2) and is involved in the degradation of p27(Kip1) through the ubiquitin/proteasome pathway. In addition, p45(SKP2) facilitates proteolysis of other molecules related to the cell cycle, is frequently over-expressed in transformed cells, and induces S phase in quiescent cells. The aim of this study was to determine whether p45(SKP2) expression is altered in aggressive lesions of Kaposi's sarcoma and its relation to p27(KIP1)down-regulation. We performed immunohistochemistry using antibodies directed to p45(SKP2), p27(KIP1), and Ki67 on paraffin blocks corresponding to 47 cases of Kaposi's sarcoma (8 macules, 10 plaques, 12 tumors, and 15 extracutaneous lesions). p45(SKP2) nuclear over-expression was present in all Kaposi's sarcoma stages, being significantly increased in skin tumors (mean +/- 95% confidence interval: 39.2 +/- 18.8) and extracutaneous lesions (25.8 +/- 17.3) as compared with macules (18.9 +/- 8.2) and plaques (29.2 +/- 12.0; P =.0199). On the other hand, Kaposi's sarcoma progression was associated with a decrease in p27(KIP1) expression and Ki67 immunoreactivity was independent of disease stage. No statistically significant differences were found in regard to patients' sex and human immunodeficiency virus status and regression analysis failed to show a correlation among p45(SKP2), p27(KIP1) and Ki67 immunostaining scores. These findings suggest that p45(SKP2) is involved in Kaposi's sarcoma progression, not only by promoting the degradation of p27(KIP1) but also through other mechanisms still unknown.

Erythema-multiforme-like eruption due to topical contactants: expression of adhesion molecules and their ligands and characterization of the infiltrate

Erythema-multiforme-like reactions are a rare manifestation of allergic contact sensitivity, the pathomechanisms of which and their possible relationship to erythema multiforme remain unclear. We present our histopathological and immunohistochemical findings regarding the expression of several adhesion molecules and immunophenotypic markers of the infiltrate in skin biopsy specimens from 2 cases of erythema-multiforme-like reactions due to contact sensitizers and 3 cases of typical post-herpetic erythema multiforme. The histopathological pattern of erythema-multiforme-like reactions was characterized by an upper-dermal perivascular lymphoid infiltrate with exocytosis and keratinocyte necrosis; in 1 of the cases, there were foci of spongiosis and an admixture of eosinophils in the infiltrate. In comparison with biopsy specimens from cases of typical erythema multiforme, in both cases of erythema-multiforme-like reactions, the epidermal expression of ICAM-1 was more prominent, the % of CD4+ cells in the infiltrate was higher and the % of CD69+ cells was lower. There were no other significant differences in the cell phenotype of the infiltrate or in adhesion molecule expression in biopsy samples from both disorders.