Cutaneous CD30+ Lymphoproliferative Disorders

This presentation will focus on primary cutaneous CD30+ T-cell lymphoproliferative disorders which has been recognized as a spectrum comprising lymphomatoid papulosis (LyP) at the benign end of the spectrum and primary cutaneous anaplastic large cell lymphoma at the malignant end. While the classic subtypes of lymphomatoid papulosis A, B and C are well known, newer subtypes have emerged namely subtypes D and E, and one with chromosomal rearrangements involving the DUSP22-IRF4 locus. Case examples will be illustrated which underscore the importance of awareness of these subtypes that can mimic more aggressive forms of lymphomas. For primary cutaneous anaplastic large cell lymphoma, the biggest challenge remains in differentiating from transformed MF. Though histopathological features can help to support one or the other, it cannot be emphasized enough that the only way is through careful clinicopathological correlation for a definitive diagnosis.