Lymphomatoid papulosis and associated lymphomas: a retrospective case series of 84 patients

Aims. To determine incidence and risk factors for developing lymphoma in patients with lymphomatoid papulosis (LyP), and to identify putative triggers amenable to treatment. Methods. The prognostic effect of severity of LyP, viral infection by history or serology, beta-2-microglobulin level, lactic dehydrogenase (LDH) level, and CD4 : CD8 ratio were evaluated using logistic regression models. Responses to prophylactic or palliative treatment were assessed. Results. In total, 84 patients (38 men, 46 women, median age at diagnosis 48.5 years) were identified. Of these, 34 (40%) were also diagnosed with one or more lymphomas: 16 (19%) had mycosis fungoides, 15 (17%) had primary cutaneous anaplastic large-cell lymphoma (pcALCL), 2 had both MF and pcALCL, and 1 had MF with large cell transformation and 1 had peripheral T-cell lymphoma. Of the 61 people presenting with LyP alone, only 11 (18%) subsequently developed lymphoma, with a median onset of 17.6 years (95% CI: 4, not obtained). Men were 2.5 times more likely than women to develop lymphoma (P = 0.04). Exposure to Epstein-Barr virus (EBV) was associated with an increase in incidence of 4.8 times (P = 0.16). Treatment for a putative infectious trigger resulted in improvement for 15 of 24 patients (63%). Conclusion. Referral bias may explain the higher (40%) incidence of lymphoma in this population of LyP patients, compared with the 10-20% incidence commonly cited in the literature. In the subset of patients presenting with LyP alone, only 18% later developed lymphoma. Male patients or patients with prior EBV infection may have a higher risk for developing lymphoma, and some patients improved with treatment of putative infectious triggers.