Atlas of dermatopathology: Mycosis fungoides

+ Introduction

+ Literature

+ Support

+ Skin biopsy

+ Non-tumorous skin diseases

+ Skin tumors

+ Mesenchymal tumors

+ Cysts of the skin and subcutis

+ Soft tissue lesions

+ Some lesions of the oral cavity

+ Dermatovenerology

+ Collection of histological slides by prof. Günter Burg

+ Collection of histological slides by prof. Werner Kempf

+ Collection of histological slides of dr. Ram Chandra Adhikari

Mycosis fungoides

Introduction

One of the most common forms of the skin lymphoma.

Clinical signs

location: no predilection, often on the trunk
I. premycotic stage: lesions resemble chronic eczema; recurrent pink patches, roundish or digitate
II. infiltrative stage: infiltration of the lesions, color gets more prominent, often circular configuration
III. tumorous stage: the tumorous lesions sometimes resemble fungi
hyperpigmentation, ulceration of the tumors
lymphnodes and internal organs are affected in late stages

Mycosis fungoides II. (824)

Mycosis fungoides III. (834)

Pictures

Mycosis fungoides I., eczematous lesions: Mycosis fungoides - plaque stage, Clinical picture (823)

Mycosis fungoides I.: Mycosis fungoides - plaque stage, Clinical picture (824)

Mycosis fungoides I., trunk: Mycosis fungoides - plaque stage, Clinical picture (825)

Mycosis fungoides II., buttocks: Mycosis fungoides - plaque stage, Clinical picture (826)

Mycosis fungoides II.: Mycosis fungoides - plaque stage, Clinical picture (827)

Mycosis fungoides II., breast: Mycosis fungoides - plaque stage, Clinical picture (828)

Mycosis fungoides II., typical configuration: Mycosis fungoides - plaque stage, Clinical picture (829)

Mycosis fungoides II., early infiltration: Mycosis fungoides - plaque stage, Clinical picture (830)

Mycosis fungoides III., chest: Mycosis fungoides - plaque stage, Clinical picture (831)

Mycosis fungoides III., ulcerations: Mycosis fungoides - plaque stage, Clinical picture (832)

Mycosis fungoides III., thigh: Mycosis fungoides - plaque stage, Clinical picture (833)

Mycosis fungoides III., necrotising tumor: Mycosis fungoides - plaque stage, Clinical picture (834)

Mycosis fungoides I., eczematous changes: Mycosis fungoides - plaque stage, Clinical picture (835)

Mycosis fungoides I., neck: Mycosis fungoides - plaque stage, Clinical picture (836)

Mycosis fungoides II., early tumorous stage: Mycosis fungoides - plaque stage, Clinical picture (837)

Mycosis fungoides I., parapsoriasis en plaque: Mycosis fungoides - plaque stage, Clinical picture (838)

Histology

Histology is variable, in early lesions not specific. Differentiation from superficial dermatitis is problematic. Some of more common signs are: infiltration of the papillary dermis, infiltration of the basal layer of the epidermis (especially of the tips of the rete ridges), lymphocytic infiltration of the epidermis (exocytosis), usually without spongiosis (but spongiotic variant of the MF exists). Later epidermal accumulations of lymphocytes (Pautrier's abscesses) appear. At that time the polymorphism of lymphocytes is usually evident. Moreover, intraepidermal lymphocytes are somewhat larger than those located within the dermis. The infiltrate gets denser and scattered eosinophils appear. Papillary dermis gets fibrotic. Perivascular infiltrate in the upper dermis is sometimes asymmetric, denser in upper (epidermal) epidermal part.

Later stages are characterised by dense, polymorphic dermal infiltrate, often with mitotic activity. Tumorous nature of the infiltrate is evident. Atypical lymphocytes enter the follicular epithelium (and may cause secondary follicular mucinosis and/or destruction of the follicles). Blastic transformation is characterized by large lymphoid elements and high mitotic activity.

When initial stages of mycosis fungoides are treated with PUVA, the epidermotropic lymphocytes disappear, but still may be present within the follicular epithelium.

Immunophenotype and genetic features: