Mycosis fungoides with reactive lymphoid follicles may represent an early histopathologic picture of granulomatous slack skin

A Rare Case of Solitary Hemorrhagic Mycosis Fungoides With Angiocentric Features

Unilesional (solitary) mycosis fungoides (MF) is a rare variant characterized clinically by the presence of a single contiguous area of skin involvement covering less than 5% of the body surface and histopathologically by features identical to those seen in classical MF. Angiocentricity (angiodestruction) is mostly a feature of primary or secondary cutaneous lymphomas with an aggressive course and poor outcome, with only very few reports of MF with angiocentric pattern. The authors report an unusual case of solitary patch-stage MF with hemorrhagic features, characterized histologically by epidermotropic and angiocentric (angiodestructive) infiltrate and a reactive B-cell component appearing as lymphoid follicles.

A specific DNA methylation profile correlates with a high risk of disease progression in stage I classical (Alibert-Bazin type) mycosis fungoides

BACKGROUND

Mycosis fungoides (MF) is the most common type of cutaneous T-cell lymphoma; in its classical presentation it evolves slowly, but it can have an aggressive course in a subset of patients.

OBJECTIVES

To investigate the impact of epigenetic mechanisms on the progression of early stage MF.

METHODS

We analysed DNA methylation at 12 different loci and long interspersed nucleotide elements-1 (LINE-1), as a surrogate marker of global methylation, on tissue samples from 41 patients with stage I MF followed up for at least 12 years or until disease progression. The methylation profiles were also analysed in two T-cell lymphoma cell lines and correlated with gene expression.

RESULTS

The selected loci were methylated in a tumour-specific manner; concomitant hypermethylation of at least four loci was more frequent in cases progressing within 1-3 and 3-6 years than in late-progressive or non-progressive cases. LINE-1 methylation was significantly lower in rapidly progressive MF at 3 years (61%, P < 0·001) than in those at 12 years (67%). PPARG, SOCS1 and NEUROG1 methylation showed remarkable differences among the prognostic groups, but only PPARG was a significant predictor of disease progression within 6 years, after adjustment for patients' age or gender. Strikingly, a methylation profile similar to progressive cases was found in highly proliferative Sézary-derived HUT78 cells but not in MF-derived HUT102 cells. Exposure to a DNA demethylating agent restored sensitivity to apoptosis and cell cycle arrest.

CONCLUSIONS

Epigenetic silencing of specific biomarkers can predict the risk of disease progression in early-stage MF, providing insights into its pathogenesis, prognosis and therapy.