Skip to Main Content

INTRODUCTION

Cutaneous lymphomas are a group of disorders characterized by the localization of malignant lymphocytes (tropism) to the skin. Lymphomas presenting in the skin may be due to primary or secondary involvement. In clinical practice, primary cutaneous lymphomas are more common and often seen by dermatologists at presentation, while lymphomas due to secondary involvement represent metastatic disease from a primary nodal or systemic lymphoma, and are associated with a worse prognosis. Primary cutaneous lymphomas, by definition, are cutaneous lymphomas with no extracutaneous manifestations of the disease at presentation.

Within the group of primary cutaneous lymphomas, T-cell lymphomas are more common, comprising approximately two-thirds of cases, in contrast to nodal lymphomas where B-cell lymphomas predominate over T-cell lymphomas.

MYCOSIS FUNGOIDES

Mycosis fungoides (MF) represents the most common type of cutaneous lymphoma and is a malignancy of CD4+ skin homing, helper T-cells (Figures 12–1, 12–2, 12–3, 12–4, 12–5, 12–6, 12–7, 12–8, 12–9, 12–10, 12–11, 12–12, 12–13, 12–14, 12–15, 12–16, 12–17, 12–18, 12–19, 12–20, 12–21, 12–22, 12–23, 12–24, 12–25, 12–26, 12–27, 12–28). It has an indolent behavior, in which patients present with patches in the early stages, with the sequential development of plaques and tumors over time. However, many patients remain well for many decades, with patch and plaque stage disease and only in about 10% of cases do patients develop progressive disease to tumor stage or extracutaneous involvement.

Figure 12-1

Patch stage mycosis fungoides

This patient has early stage lesions of MF, with multiple atrophic erythematous patches in a bathing trunk distribution. The atrophic patches have a cigarette papery appearance.

Figure 12-2

Patch stage mycosis fungoides—histology

The neoplastic lymphocytes demonstrate epidermotropism, tending to infiltrate the epidermis in a single array or in small clusters. They characteristically contain irregularly shaped “cerebriform” nuclei with a surrounding perinuclear halo. It is often difficult to diagnose early patch stage MF, as the histological features and cytological atypia can be very subtle.

Figure 12-3

Plaque stage mycosis fungoides

There are disseminated erythematous plaques on the lower abdomen of this patient. The lesions are more infiltrated and have polycyclic borders. The presence of trailing scales at the borders mimics erythema annulare centrifugum. Histological examination is necessary to diagnose.

Figure 12-4

Plaque stage mycosis fungoides—histology

The histology of plaque stage MF differs from that of patch stage MF in that the former has more prominent epidermotropism of neoplastic cells, which are dispersed in clusters forming Pautrier’s microabscesses. There is also a denser, often lichenoid lymphocytic infiltrate in the superficial dermis, ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.