Sean Klepper M.D.
Artur Zembowicz M.D....
- Chronic relapsing disease characterized by papulonodular lesions that spontaneously regress, leaving hyper- or hypopigmented scars
- Most commonly on the trunk and extremitites of adults
- Some patients eventually develop a secondary lymphoma.
- LyP type A lesions (most common):
- Wedge-shaped dermal infiltrate that often extends into the subcutaneous fat
- The infiltrate is composed of mitotically active medium-sized to large pleomorphic cells admixed with numerous neutrophils and eosinophils
- LyP type B (rare):
- Epidermotropic infiltrate of amall to medium-sized cells indistinguishable from mycosis fungoides
- LyP type C:
- Cohesive sheets of tumor cells with few admixed neutrophils
- Helper T-cell phenotype (CD3+, CD4+, CD5+, CD8-) with characteristic positivity for CD30 and TIA-1