Lymphomatoid papulosis: reappraisal of clinicopathologic presentation and classification into subtypes A, B, and C.

OBJECTIVES: To analyze clinicopathologic features of lymphomatoid papulosis and delineate the characteristics of histopathologic variants (types A, B, and C).

DESIGN: Retrospective nonrandomized study.

SETTING: University-based dermatologic referral center.

PATIENTS: Eighty-five patients with lymphomatoid papulosis. Clinical data and 1 or more biopsy specimens were available for review in all cases. When possible, immunophenotypic and molecular analyses were carried out.

RESULTS: Of these patients, 78 presented only 1 histopathologic subtype of lymphomatoid papulosis (64 had type A, 3 had type B, and 11 had type C). The last 7 patients presented more than 1 subtype (1 had A and B, 5 had A and C, and 1 had A, B, and C). Two patients had regional lymphomatoid papulosis, an unusual clinical presentation characterized by groups of lesions localized to 1 anatomic region. We observed, we believe for the first time, that some histopathologic patterns, ie, follicular mucinosis (n = 1), syringotropic infiltrates (n = 1), epidermal vesicle formation (n = 2), and syringosquamous metaplasia (n = 1), were associated with lymphomatoid papulosis. A distribution along hair follicles, or follicular lymphomatoid papulosis, was observed in 5 biopsy specimens. A bandlike rather than a wedge distribution of the infiltrate was seen in 5 specimens from patients with lymphomatoid papulosis type A. Of 8 patients who had associated lymphoid malignancies, 4 had Hodgkin disease and 4 had mycosis fungoides.

CONCLUSIONS: Lymphomatoid papulosis is a cutaneous disorder with multiple clinicopathologic features. Differentiating between mycosis fungoides and anaplastic large cell lymphoma may be very difficult and sometimes impossible. In the spectrum of CD30(+) cutaneous lymphoproliferative disorders, boundaries between these 2 entities are not clear-cut.