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Lymphomatoid
papulosis (LyP) is a recurrent hemorrhagic papular skin eruption with a
clinically benign course and histopathologic features of lymphoma.
The lesions
usually present as papules and nodules that
spontaneously involute.
nitially the
lesions are smooth but later these lesions become crusted, ulcerated and
necrotic.
Lymphomatoid
papulosis can only be diagnosed accurately through a careful history in
which the characteristic waxing and waning of the skin lesions is
identified and through proper communication between clinicians and
pathologists.
Visit:
Primary Cutaneous
Lymphoma ;
Cutaneous
Pseudolymphoma ;
Role of immuno-histochemistry in Dermatopathology
Age:
Usually occurs in the
third and fourth decade of life. This lesion may also occur in
children.
Site:
Trunk ;
Proximal parts of the limb ; face ; scalp ; palms and sole .
Microscopic
features:
Image
Link(Dr Weems) ;
Subtypes-
LyP Type
A ; LyP Type B ; LyP Type C.
LyP Type A :
Wedge-shaped,
superficial and deep
mixed infiltrate of small
lymphocytes, abnormal lymphocytes and, often, plasma cells, neutrophils,
and eosinophils ;
Abnormal lymphocytes
with large pleomorphic nuclei ; Binucleate abnormal lymphocytes that
resemble Reed-Sternberg's cells and multinucleate abnormal lymphocytes;
There is no epidermotropism .
LyP
Type B :
Perivascular or band like dermal infiltrate; Small to medium sized
lymphocytes with cerebriform nuclei;
There is
epidermotropism. (Features resemble plaque stage mycosis fungoides).
LyP Type C :
Monotonous
population of large atypical cells ; There are fewer inflammatory
cells. (Features resemble ALCL).
Image
Link1 ;
Image Link2 (CD30+cells)
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Immunohistochemistry:
Large Atypical
cells( LyP type A & C):
CD30+ ; CD3+ ;
CD2 -/+
; CD4 +/-
; CD8 -
; CD15 and EMA are usually negative.
Atypical cells
(LyP typeB):
CD3+ ; CD4+ ; CD8 -
; Cells do not express CD30. |
Differential
diagnosis: Differentiating
between mycosis fungoides and anaplastic large cell lymphoma
and Hodgkin's disease
may be very difficult .
Mycosis fungoides
consists of abnormal lymphocytes that may be identical to those of
lymphomatoid papulosis, but infiltrates tend to be bandlike, not
wedge-shaped.
No neutrophils are present as
a rule in mycosis fungoides.
Lesions of
Hodgkin's disease usually do not display a wedge-shaped infiltrate and
exhibits Reed-Sternberg's cells consistently.
Clinical,
microscopic and immunohistochemical features of lymphomatoid papulosis and anaplastic
large cell lymphoma (ALCL) may overlap.
Both Primary cutaneous CD30-positive ALCL and lymphomatoid papulosis are characterized by CD30-positive
large atypical cells predominantly of T-cell origin.
Insect bites
exhibit a wedge-shaped infiltrate composed of lymphocytes and eosinophils.
Slightly abnormal lymphocytes may be present but these are not in mitosis.
Pityriasis
lichenoides et varioliformis acuta.
Click here (Dr Weems)
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