Page 80 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 3-15 Integumentary System

CLINICAL SUBTYPES OF CUTANEOUS T-CELL LYMPHOMA

Erythrodermic patient
with erythema on greater
than 90% of body
surface area

MYCOSIS FUNGOIDES

Mycosis fungoides is the most common form of cutane-
ous T-cell lymphoma. The cutaneous T-cell lympho-
mas are an assorted group of cancers with varying
genotypes and phenotypes. Mycosis fungoides is a rare
form of cancer, but it is considered to be the most
frequent form of cutaneous lymphoma. Mycosis fun-
goides is predominantly a disease of abnormal CD4+
lymphocytes that have become malignant and have Sézary cells:
moved into the skin, causing the characteristic lesions. atypical
Advances with immunophenotyping and gene re- cerebriform
arrangement studies have helped to characterize the lymphocytes
disease and are used for diagnostic and prognostic pur-
poses. Altogether, mycosis fungoides is a rare condition
afflicting approximately 1 in 500,000 people.
Clinical Findings: Mycosis fungoides often mani-
fests as a slowly progressing rash that occurs in double-
covered areas such as the groin and breast skin. The
buttocks are a very common area of involvement.
There is a 2 : 1 male predominance. Mycosis fungoides
is seen in all races, with a predominance in the African
American population compared with the Caucasian or
Asian population. It is infrequently encountered in
children. Mycosis fungoides is staged based on its
appearance, the body surface area (BSA) involved, and
the involvement of lymph nodes, blood, and other
organ systems. The most common stage of mycosis
fungoides is stage IA.
Stage IA mycosis fungoides carries an excellent
prognosis, with most patients leading a normal life
span and dying from another cause. Stage IA disease
is typically described as patches of involvement total-
ing less than 10% of the BSA and no lymph node
involvement. The rash of stage IA disease appears as
thin, atrophic patches on the buttocks, breasts, or
inner thighs. There are often areas of poikiloderma
(hyperpigmentation and hypopigmentation as well as
telangiectasias and atrophy). The atrophy has been
described as “cigarette paper” atrophy: The skin exhib-
its a fine crinkling similar to freshly rolled cigarette
paper. The rash is often asymptomatic, but pruritus
can be problematic for some. The diagnosis of mycosis Patch stage of mycosis fungoides on the buttocks.
fungoides is based on the clinical and pathological Atrophic poikilodermatous patches are frequently
findings. encountered on the buttocks. Annular plaques
Patch-stage mycosis fungoides can go undiagnosed
for years to decades because of its indolent nature and
often bland appearance. It often appears as psoriasis, a
nonspecific form of dermatitis, and initial biopsies are may start as a form of dermatitis and over many years leukemic phase of mycosis fungoides. Sézary syndrome
often nonspecific. The application of topical steroids transform into a malignant CD4+ process. has a poor prognosis.
before a skin biopsy is obtained may alter the histologi- At the other end of the spectrum is the Sézary syn- There are many varying stages of disease between
cal picture enough to make the diagnosis of mycosis drome. This is an erythrodermic variant of mycosis fun- these two extremes. The morphology of cutaneous lym-
fungoides impossible. Often, serial biopsies over years goides with peripheral blood involvement. Circulating phoma changes from patches to plaques to nodules or
are required until one shows the characteristic features Sézary cells are the hallmark of this syndrome. The tumors. Varying amounts of ulceration may be present.
of mycosis fungoides. It is best to biopsy a previously Sézary cells are enlarged lymphocytes with cerebriform The natural history of progression of mycosis fungoides
untreated area. In addition to being a very slow- nuclei. The cerebriform nuclei can best be appreciated is variable and difficult to predict clinically. The most
developing cancer, it is possible that mycosis fungoides under electron microscopy. It is considered to be a accurate way to predict the course is based on the type of

66 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS