Increased risk of lymphoid and nonlymphoid malignancies in patients with lymphomatoid papulosis.

BACKGROUND: Lymphomatoid papulosis (LyP) is a rare skin disease with malignant potential. The long term outcomes of patients with this disease have not been adequately assessed.
METHODS: Fifty-seven patients with biopsy-proven LyP and 67 controls matched for age, gender, and race were followed prospectively from 1988 to 1996. Reported malignancies were confirmed by surgical pathology and/or autopsy reports. A search through the National Death Index through December 1995 was conducted to identify all deaths, and death certificates were procured. Expected numbers of malignancies based on SEER data were calculated for both the patient and the control groups.
RESULTS: Six LyP patients (10.5%) and 1 control (1.5%) reported nonlymphoid malignancies (P = 0.047). Two patients and no controls developed lymphoid malignancies (mycosis fungoides and CD30(+) cutaneous lymphoma). The expected numbers of nonlymphoid and lymphoid malignancies in the LyP patient group, based on the SEER data, were 1.93 and 0.15, respectively, yielding a relative risk (with 95% confidence interval) of 3.11 (1.26-6.47) for nonlymphoid malignancies and 13.33 (2.24-44.05) for malignant lymphomas in the LyP patients. There was no significant difference between the observed and expected numbers of malignancies in the control group. Four LyP patients died during the follow-up, three due to malignancies; and one control died of a gunshot wound to the head (suicide). The difference in overall survival between the LyP patients and the controls was not statistically significant (P = 0. 12).
CONCLUSIONS: Patients with LyP appear to have an increased risk of both lymphoid and nonlymphoid malignancies. The increased risk of nonlymphoid as well as lymphoid malignancies may suggest a basic underlying genetic defect leading to the development of malignancy in LyP patients. Copyright 1999 American Cancer Society.