Lymphomatoid papulosis (LyP) is a recurrent, self-healing papulonodular skin eruption with histologic features of a CD30+ malignant T cell lymphoma [1,2]. LyP is part of the group of cutaneous CD30+ lymphoproliferative disorders (LPDs) that includes primary cutaneous anaplastic large cell lymphoma (pcALCL) and borderline CD30+ lesions.
LyP is characterized by a chronic course, lasting years or decades. Grouped or disseminated papules and nodules develop and spontaneously regress over weeks to months (picture 3D). Patients with LyP have an excellent prognosis, although they are at increased risk of developing a second cutaneous or nodal lymphoma, such as mycosis fungoides, pcALCL, or Hodgkin lymphoma.
This topic will discuss the clinical presentation, diagnosis, and treatment of LyP. Other cutaneous T cell lymphomas are discussed separately.
Lymphomatoid papulosis (LyP) is a rare disease. It occurs in patients of all ethnic groups with a peak incidence in the fifth decade. However, LyP may occur in children and individuals older than 50 years [3-5]. In a series of 111 patients, 60 percent of male patients but only 25 percent of female patients were ≤18 years old at the time of diagnosis (figure 1) .