Extrafacial indolent CD8‐positive cutaneous lymphoid proliferation with unusual symmetrical presentation involving both feet

Abstract

Indolent CD8+ cutaneous lymphoid proliferation represents a recently described entity among cutaneous T-cell lymphomas that typically presents with solitary skin lesions on the face or at acral sites and usually follows an indolent clinical course. Histopathologically, this entity is characterized by a dense dermal infiltrate of non-epidermotropic, small- to medium-sized pleomorphic CD8+ T-cells of the non-activated cytotoxic phenotype showing a clear-cut grenz zone and a low proliferation index. Distinction from otherwise aggressive T-cell lymphomas bearing a cytotoxic CD8+ phenotype is fundamental. We herein present an unusual case of indolent CD8+ cutaneous lymphoid proliferation presenting in bilateral symmetrical distribution on both feet and lacking the otherwise described grenz zone. Our case widens the spectrum of possible clinical and histomorphological variations of this entity. Taking into account the distinctive and unique clinical and microscopic features of all hitherto published cases of indolent CD8+ cutaneous lymphoid proliferation we suppose that this lymphoma subtype has to be included as a new and distinct entity in the World Health Organisation (WHO)-/European Organisation for Research and Treatment of Cancer (EORTC)-classification of cutaneous lymphomas.

Indolent CD8‐positive lymphoid proliferation of acral sites: three further cases of a rare entity and an update on a unique patient

“…Including this series, there have been 51 cases of indolent CD8‐positive lymphoid proliferation reported to date (Table ). The term was originally used to describe four patients with slowly progressive nodules or plaques confined to one or both ears, characterized by a nonepidermotropic infiltrate of monomorphous blast‐like T‐cells in the dermis with a CD3(+) CD4(−) CD8(+) CD30(−) TIA‐1(+) Granzyme B(−) BF‐1 (+) CD56(−) immunophenotype, a low proliferation fraction and the presence of clonal T‐cell receptor (TCR) gene rearrangements in three out of four cases.…”

“…Affected individuals are mostly older than 50 years (mean age 56 years) and a slight male predominance has been observed (M:F 1.7:1). Although the majority of cases (28/51 = 55%) arise on the ear, it is now recognized that lesions may occur at other locations, particularly on the nose, and on the hands and feet, suggesting that a local antigenic stimulus specific to the ear is unlikely . The indolent nature of the process, and innocuous clinical appearance, might lead to a consideration of a reactive rather than lymphomatous process, however the monotonous and cytologically atypical infiltrate, the abnormal loss of T‐cell associated antigens, and clonality, militate against this interpretation.…”

“…Forty‐four further cases of so‐called indolent CD8‐positive lymphoid proliferation of the ear have since been reported or identified, retrospectively with the original description widened to include lesions arising on the nose and at other acral sites, and some variation in pathological features, whilst maintaining an indolent clinical evolution (Tables and ). We present three further cases of this enigmatic entity seen in our institutions and provide an update on a previously reported unique case …”

Early lymphoid lesions: conceptual, diagnostic and clinical challenges

“…93 Histology typically shows a non-epidermotropic, dense dermal lymphoid infiltrate composed of medium-sized atypical CD8 + T cells positive for TIA-1, but negative for Granzyme B ( Figure 3D-F). T-cell clonality has been demonstrated in most cases.…”

Double‐positive CD8/CD4 primary cutaneous acral T‐cell lymphoma

“…Interestingly, the indolent clinical course of acral CD8 + TCL has led to the hypothesis that it may also represent a reactive process, because indolent CD8 + lymphoid proliferations lacking clonal TCR rearrangements have been described both in the ear and at extra‐facial sites, albeit not in conjunction with a CD4 + /CD8 + phenotype, as in our case. Nevertheless, the frequent monoclonality and aberrant loss of T‐cell antigens in acral CD8 + TCL support its definition as a truly malignant lymphoproliferative disorder, while the presence of nuclear atypia and aberrant phenotype suggest a disorder generally similar to primary cutaneous small/medium‐sized T‐cell lymphoproliferations and argue against a purely reactive process . The dot‐like positivity for CD68 is a peculiar finding of acral CD8 + TCL, allowing to distinguish it from other CD8 + cutaneous lymphoproliferative disorders …”