Abstract

Lymphomatoid Papulosis (LyP) is a CD30-lymphoproliferative disorder characterized by crops of raised, red-brown lesions and a population of enlarged, CD30+ lymphocytes. Although not necessarily malignant in many cases, LyP is an important diagnosis; patients with LyP are at increased risk of developing other disorders, such as mycosis fungoides, Hodgkin disease and other lymphomas. LyP harbors several pitfalls for clinicians and pathologists. The folliculotropic variant is a rare form of the disease, reported only 11 times in the literature. We present a case of a 51-year-old man with features clinically consistent with folliculitis, highly recalcitrant to therapy, recurring on the arms, legs, and trunk for over a year. The biopsy revealed features typical of the follicular variant of LyP: large, perifollicular, mitotically active lymphocytes that uniformly have strong expression of CD30. On review of the patient’s history, prior biopsies had perifollicular infiltrates, some of which had cells large enough to cause suspicion for Langerhans cell histiocytosis. But, these did not express Langerhans cell markers. Mimickers of LyP, such as arthropod assault, scabies, primary cutaneous anaplastic large cell lymphoma and pityriasis lichenoides, were excluded through clinicopathologic correlation. We review the special features of this rare variant of LyP, and detail histologic clues that can help avoid misdiagnosis as a folliculitis.

Financial Disclosure:
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