Make the Diagnosis

Asymptomatic, erythematous papules on the neck

A healthy 65-year-old white female with no significant past medical history presented with asymptomatic, erythematous papules on her neck. The lesions have been present for 2 weeks. The patient recalled similar outbreaks over the years that resolved with topical steroids. No biopsies were performed in the past.

Make the diagnosis:

Contact dermatitis

Herpes zoster

Lymphomatoid papulosis

Arthropod assault

The patient’s biopsy showed sparse and grouped and slightly enlarged atypical stained mononuclear cells in mostly perifollicular areas with focal epidermotropism. CD30 staining was positive. She responded to potent topical steroids.

Lymphomatoid papulosis (LyP) is an uncommon skin disorder. While all ages may be affected, the peak incidence occurs in the fourth or fifth decade. The etiology of LyP is unknown. It is unclear whether the proliferation of T-cells is a benign and chronic disorder, or an indolent T-cell malignancy.

In addition, 10% of LyP cases are associated with anaplastic large-cell lymphoma, cutaneous T-cell lymphoma (mycosis fungoides), or Hodgkin lymphoma. Borderline cases are those that overlap LyP and lymphoma.

Patients typically present with crops of asymptomatic erythematous to brown papules that may become pustular, vesicular, or necrotic. Lesions tend to resolve within 2-8 weeks with or without scarring. The trunk and extremities are commonly affected. The condition tends to be chronic over months to years. The waxing and waning course is characteristic of LyP. Constitutional symptoms are generally absent in cases not associated with systemic disease.

Dr. Donna Bilu Martin

Histopathologic examination reveals a dense wedge-shaped dermal infiltrate of atypical lymphocytes along with numerous eosinophils and neutrophils. Epidermotropism may be present and lymphocytes stain positive for CD30+. Vessels in the dermis may exhibit fibrin deposition and red blood cell extravasation. Histologically, LyP can be classified as Type A to E. These subtypes are determined by the size and type of atypical cells, location and amount of infiltrate, and staining of CD30 and CD8.

The differential diagnosis of LyP includes pityriasis lichenoides, anaplastic large cell lymphoma, cutaneous T-cell lymphoma, folliculitis, arthropod assault, Langerhans cell histiocytosis, and leukemia cutis. Treatment is symptomatic. Mild forms of LyP can many times be managed with superpotent topical corticosteroids. Bexarotene gel has been used for early lesions. For more widespread or persistent disease, intralesional corticosteroids, phototherapy (UVB or PUVA), tetracycline antibiotics, and methotrexate have been reported to be effective. Refractory cases may respond to interferon alpha or oral bexarotene. Routine evaluations are recommended as patients may be at increased risk for the development of lymphoma.

This case and photo were submitted by Dr. Bilu Martin.

Dr. Bilu Martin is a board-certified dermatologist in private practice at Premier Dermatology, MD, in Aventura, Fla. More diagnostic cases are available at mdedge.com/dermatology. To submit a case for possible publication, send an email to [email protected].

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