In search of prognostic indicators for lymphomatoid papulosis: a retrospective study of 123 patients.

BACKGROUND: Lymphomatoid papulosis (LyP) is a benign recurrent papulonodular skin eruption with histologically malignant features that sometimes (10%-20%) progresses to lymphoma.

OBJECTIVE: We retrospectively evaluated the clinical course of patients with LyP and identify prognostic factors possibly indicating a malignant course.

METHODS: Clinical, histopathologic, and immunologic features and molecular genetics were examined and correlated with clinical course and outcomes. Immunophenotyping and chemokine profiling were performed in select skin biopsy samples. A follow-up questionnaire was sent to patients. Clinical course and association with neoplastic disorders were correlated with LyP subtypes, molecular genetics, and immunophenotyping studies.

RESULTS: Of 123 patients with LyP (1991-2008) followed up a mean of 4 years (range, 2 months to 14 years), 17 (14%) had an associated hematologic malignancy, 8 of which were mycosis fungoides. Histopathologic analyses demonstrated classic LyP type A (n = 69), B (n = 13), or C (n = 6), and a slight predominance of T-cell CD8 marker expression for type A. More than one type of lesion was present in 9 patients with a higher incidence of hematologic malignancies. T-cell receptor gene rearrangement positivity was about two times higher, with LyP associated with hematologic malignancy (82% vs 44%; odds ratio 5.7; P = .02). Chemokine studies in a subset of 25 patients showed chemokine receptor (CCR) CCR4(+) and thymus and activation-related chemokine (TARC(+)) in all LyP types and CCR3(+) and chemokine-related receptor (CXCR) CXCR3(+) in types B and C.

LIMITATIONS: Retrospective study design is a limitation.

CONCLUSIONS: Positive T-cell receptor gene rearrangement or diagnosis of mixed-type LyP may be a prognostic indicator of disease more prone to progress to lymphoma.