Objective: To describe the diagnostic difficulties, response to therapy, and clinical features of lymphomatoid papulosis and the cumulative frequency of transformation to lymphoma.
Design: Case series.
Setting: University hospitals.
Methods: The records of 21 patients with lymphomatoid papulosis who were seen from 1986 to 1993 were retrieved from the archives of two institutions. The entry criteria for the study were lymphomatoid papulosis misdiagnosed at the time of original presentation or lymphomatoid papulosis that later developed into lymphoma.
Results: When lymphomatoid papulosis tissues are pathologically examined, they are frequently confused with lymphoma, melanoma, or carcinoma. Eight of the 19 patients whose condition was misdiagnosed as malignant received either chemotherapy or radiotherapy. Although lymphomatoid papulosis responded to cytotoxic chemotherapy, the remissions were transient and promptly recurred after or during treatment. However, all five cases that became malignant responded to chemotherapy and have not recurred. Five of 21 patients (24%) developed lymphoma, but the cumulative risk for transformation after 15 years was 80%.
Conclusions: Lymphomatoid papulosis can only be diagnosed accurately through a careful history in which the characteristic waxing and waning of the skin lesions is identified and through proper communication between clinicians and pathologists. Patients with lymphomatoid papulosis have an increased risk for developing lymphoma that is much higher than the 15% to 20% quoted in the literature. Patients who develop lymphoma respond well to cytotoxic chemotherapy and can be cured with appropriate therapy. Internists and oncologists need to be aware of lymphomatoid papulosis and its characteristic clinical features so that this disorder is accurately diagnosed and so that unnecessary and potentially hazardous treatment is avoided.