Lymphomatoid papulosis (LyP) is a chronic, recurrent, self-healing skin disease composed of large atypical anaplastic, immunoblastic or Hodgkin-like cells in a marked inflammatory background. In some cases the pattern of cutaneous involvement may resemble MF (type B). This neoplasm is a /3 in ICD-O-3 but was changed to a /1 in the 2001 and 2009 WHO classification. The pending ICD-O-3 errata has also changed the behavior code to a /1. This is part of the primary cutaneous CD30 positive T-cell lymphoproliferative disorders WHO group, which also includes Primary cutaneous anaplastic large cell lymphoma (see 9718/3).