Lymphomatoid papulosis
Lymphomatoid papulosis (LyP) is a rare skin disorder. The overall prevalence rate of lymphomatoid papulosis is estimated at 1.2 to 1.9 cases per 1,000,000 population. [This is a widespread misinterpretation of a 1992 study saying "the period prevalence rate of lymphomatoid papulosis was estimated to be 1.9 per 1,000,000 population for Massachusetts and 1.2 per 1,000,000 population for Pennsylvania". The authors of that study said clearly "Our estimate of 1.2-1.9 cases per 1,000,000 population should be considered a minimum estimate of the prevalence rate". That estimate was based on the 78 patients involved in the study, not the LvP population. The study recruited 11 patients from Massachusetts and 15 from Pennsylvania ]. This rare condition has only been studied in depth since 1968.

Presentation
It can appear very similar to anaplastic large cell lymphoma.
Type "A" is CD30 positive, while type "B" is CD30 negative.It has been described as "clinically benign but histologically malignant."

Treatment
It may respond to methotrexate or PUVA.

Prognosis
It can evolve into lymphoma.

See also
Cutaneous T-cell lymphoma
Parapsoriasis
Secondary cutaneous CD30+ large cell lymphoma
List of cutaneous conditions

References


== External links ==