• | CD30+ lymphoproliferative disorders – not a single entity but comprises a spectrum of disorders linked by the presence of a common neoplastic cell type |
• | big picture: primary cutaneous T-cell lymphomas represent a heterogenous group of neoplasms derived from skin-homing T cells; CD30(+) lymphoproliferative disorders are the second most common group (accounting for ~25% of all CTCL) (most common group = mycosis fungoides) |
• | disease related 5-year survival: |
• | Lymphomatoid papulosis – 100% |
• | primary cutaneous CD30(+) ALCL anaplastic large cell lymphoma – 96% |
• | secondary cutaneous CD30(+) ALCL – 24% |
• | meaning of these survival results: |
• | confirms the favorable prognoses of these primary cutaneous CD30(+) lymphoproliferative disorders |
• | underscores that LyP and CD30(+) ALCL are closely related conditions |
• | multi-agent chemotherapy is only indicated for patients with full-blown or developing extracutaneous disease |
• | stated otherwise, it is never or rarely indicated for patients with skin-limited CD30(+) lymphoma |
• | significant difference between "primary cutaneous" CD30+ ALCL and morphologically similar "systemic" CD 30+ ALCL |
• | in contrast to these systemic lymphomas, primary cutaneous CD30+ ALCL are: |
• | generally express the cutaneous lymphocyte antigen (CLA) |
• | have a significantly better prognosis |
Warning! do not "over treat" these patients:
• | referral centers for cutaneous lymphomas are confronted regularly with patients who have been misdiagnosed |
• | in particular, patients with LyP are routinely treated with multi-agent chemotherapy by physicians unaware of the spectrum of LyP (they have a histologic diagnosis of CD30+ ALCL and multifocal skin lesions) |
• | unfortunately, skin relapses shortly after systemic chemotherapy are almost the rule and give the false impression of a highly aggressive T-cell lymphoma requiring even more aggressive therapy |
TREATMENT of CD30+ lymphoproliferative disorders:
• | clear LyP – no treatment needed |
• | LyP vs. ALCL – watch 4-8 weeks: |
• | waxing and waning --> treat as LyP |
• | not waxing and waning --> treat as skin restricted ALCL |
• | skin-restricted CD30+ ALCL --> MTX or radiotherapy |
• | full blown or developing systemic disease (even regional LN involvement) --> multi-agent chemotherapy is still considered the safest option |
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