Association of combined PD-L1 expression and tumour-infiltrating lymphocyte features with survival and treatment outcomes in patients with metastatic melanoma.

BACKGROUND: Recent advances obtained with immune checkpoint inhibitors (ICIs) targeting the programmed cell death-1 (PD-1) protein have significantly improved the outcome of patients with metastatic melanoma. The PD-L1 expression in tumour cells as detected by immunohistochemistry is a predictive biomarker in some solid tumours, but appears insufficient as prognostic or predictive factor of response to ICIs in metastatic melanomas. OBJECTIVES: We investigated whether the presence and the features of pretreatment CD8+ tumour-infiltrating T lymphocytes (TILs) could be a complementary prognostic or predictive biomarker in patients with metastatic melanoma. METHODS: In this retrospective study, we evaluated the association of PD-L1 expression ≥5% of tumour cells combined with TIL features (CD8, CD28, Ki67) with the overall survival (OS) among 51 patients treated with ICIs and 54 patients treated with other treatment options (non-ICIs). RESULTS: PD-L1 positivity was observed in 33% and 39% of primary melanomas and matched metastases, respectively, with, however, poor concordance between the primary and the matched metastatic site (κ = 0.283). No significant association was noted between PD-L1 expression and CD8+ TIL profile analysed as single markers and OS or response to immunotherapy. Instead, their combined analysis in primary melanoma samples showed that the PD-L1-/CD8+ status was significantly associated with prolonged OS in the whole population (P = 0.04) and in the subgroup treated with non-ICIs (P = 0.009). Conversely, the PD-L1+/CD8+ status was a good prognostic factor in patients treated with ICIs (P = 0.022), whereas was significantly associated with poor prognosis in patients treated with non-ICIs (P = 0.014). While the expression of CD28 was not related to outcome, the Ki67 expression was significantly associated with poor OS in the subgroup CD8+ TIL+/PD-L1- (P = 0.02). CONCLUSIONS: The pretreatment combination of PD-L1 expression with the level of CD8+ TILs could better assess OS and predict therapeutic response of patients with metastatic melanoma treated by either immunotherapy or other treatment regimens.

Folliculotropic T-cell infiltrates associated with B-cell chronic lymphocytic leukaemia or MALT lymphoma may reveal either true mycosis fungoides or pseudolymphomatous reaction: seven cases and review of the literature.

BACKGROUND: Mycosis fungoides (MF) and pseudo-MF (or MF simulant) can be associated with B-cell malignancies, but distinction between a true neoplasm and a reactive process may be difficult. OBJECTIVES: To report seven patients with B-cell malignancy and folliculotropic MF or pseudo-MF and emphasize on criteria allowing distinction between the two conditions. METHODS: We retrospectively and prospectively included seven patients with B-cell malignancy who presented skin lesions histologically consisting in a folliculotropic T-cell infiltrate and reviewed the literature on the topic. RESULTS: Four men and three women had a chronic lymphocytic leukaemia (n = 6) or a MALT-type lymphoma (n = 1). Five patients had localized papules, and two had patches and plaques. Histological examination showed in all cases a diffuse dermal T-cell infiltrate with folliculotropic involvement and follicular mucinosis associated with clusters of the B-cell lymphoma, without significant expression of follicular helper T-cell markers. T-cell rearrangement studies showed a polyclonal pattern in the patients with papules and a monoclonal pattern in the cases of patches and plaques. Papular lesions had an indolent evolution, whereas patches and plaques persisted or worsened into transformed MF. CONCLUSION: Folliculotropic T-cell infiltrates associated with B-cell malignancies can be either a true folliculotropic MF or a pseudo-MF. The distinction between both conditions cannot rely only on the histopathological aspect, but needs both a clinical pathological correlation and the search for a dominant T-cell clone. Whether the neoplastic T and B cells derive from a common ancestor or the T-cell proliferation is promoted by the underlying B-cell lymphoma remains unsolved, but interaction between B and T cell in the skin does not appear to be dependent on a TFH differentiation of the T-cell infiltrate.

[Benign conjunctival tumors]. / Tumeurs conjonctivales bénignes.

Benign conjunctival tumors include congenital, melanocytic, epithelial and stromal lesions. Clinical observation often fails to make the diagnosis, and complete excisional biopsy must be performed as soon as growth is suspected. Histology remains the best way to exclude malignancy or lesions with a risk of transformation, because malignant lesions carry a poor prognosis and require specific therapy and follow-up. Onco-ophthalmologists must have a perfect knowledge of benign conjunctival tumors, since during adulthood, nevi can be confused with melanomas, and epithelial or stromal lesions with carcinomas. For children and teenagers, surgery is only recommended when growth or functional problems are observed.