| • | chronic self-healing and recurrent polymorphous papulonecrotic dermatosis |
| • | usually a "countable" number of lesions |
| • | spontaneous regression with a scar and waxing and waning of lesions |
| • | no LAN, no systemic involvement |
| • | type A – nodular or "Hodgkin’s like" |
| • | type B – band-like or "MF-like" |
| • | responds well to methotrexate and photochemotherapy, but the treatment does not seem to change the long term course |
| • | ~10 to 20% develop lymphoma (MF, Hodgkin’s, or CD30+ anaplastic large cell lymphoma) |
| • | malignant evolution cannot be predicted by clinical, histological, nor TCR gene rearrangement |
Clonality:
| • | clonal rearrangements found in 40 to 60% of cases (but this finding is not predictive of prognosis) |
| • | studies of patients with LyP and lymphoma, have generally shown the same dominant clone in both the LyP and the lymphoma lesions |
| • | CD30+ ALCL – clinically - often a solitary (ulcerating) tumor or several grouped nodules or papules restricted to 1 skin area; however, there are cases in which differentiation between the two conditions is very difficult because of indistinguishable morphological and immunophenotypical features; histology – large clusters or sheets of anaplastic CD30+ cells |
| • | because of the similarities between LyP and other types of CTCL (MF or CD30+ ALCL), the presence of a recurrent, self-healing papular or papulonodular eruption is used as a decisive criterion for the diagnosis of LyP |
| • | PLEVA: clinically – lesions are generally smaller and more numerous and run a shorter course; histology – a lichenoid infiltrate without CD30-positive cells is seen |
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| • | a sporadic, but significant association with systemic lymphoid malignancies |
| • | in adult-onset LyP, malignant transformation has been described: |
| • | ~ 5 to 20% develop lymphoma |
| • | CD30+ anaplastic large cell lymphoma (ALCL) (30%) |
| • | Hodgkin’s lymphoma (25%) |
| • | the malignancy can appear before, concurrently or after the onset of LyP (this period ranges from a few weeks to more than 40 years) |
| • | malignant evolution cannot be predicted by clinical, histological, nor TCR gene rearrangement |
| • | the types of lymphomas associated with LyP are generally associated with a favorable prognosis |
| • | this indicates excellent overall survival for LyP patients, despite the increased risk of lymphoid malignancies |
| • | it has been suggested that lymphoma complicating LyP can be recognized by enlarging or persistent skin lesions, peripheral LAN, or circulating atypical lymphocytes |
| • | and that patients be examined for these findings at least once yearly |
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| • | therapy not usually necessary except for cosmetic reasons |
| • | there is no evidence that treatment of LyP reduces the risk of subsequent malignancy |
| • | no treatment results in sustained complete remission; produce partial and temporary response |
| • | therefore only treat if symptomatic or if you anticipate scarring will be significant |
| • | super potent topical steroids (generally ineffective) |
| • | methotrexate (doses similar to psoriasis 15mg to 20mg weekly) |
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CONCEPT: CD30+ Lymphoproliferative disorders
CONCEPT: Ugly histology but benign behavior
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