LYMPHOMATOID PAPULOSIS - A T-CELL DYSCRASIA WITH A PROPENSITY TO TRANSFORM INTO MALIGNANT-LYMPHOMA

Objective: To describe the diagnostic difficulties, response to therap y, 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 lympho matoid papulosis who were seen from 1986 to 1993 were retrieved from t he archives of two institutions. The entry criteria for the study were lymphomatoid papulosis misdiagnosed at the time of original presentat ion or lymphomatoid papulosis that later developed into lymphoma. Resu lts: When lymphomatoid papulosis tissues are pathologically examined, they are frequently confused with lymphoma, melanoma, or carcinoma. Ei ght of the 19 patients whose condition was misdiagnosed as malignant r eceived either chemotherapy or radiotherapy. Although lymphomatoid pap ulosis responded to cytotoxic chemotherapy, the remissions were transi ent and promptly recurred after or during treatment. However, all five cases that became malignant responded to chemotherapy and have not re curred. Five of 21 patients (24%) developed lymphoma, but the cumulati ve risk for transformation after 15 years was 80%. Conclusions: Lympho matoid papulosis can only be diagnosed accurately through a careful hi story in which the characteristic waxing and waning of the skin lesion s is identified and through proper communication between clinicians an d 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 t o cytotoxic chemotherapy and can be cured with appropriate therapy. In ternists and oncologists need to be aware of lymphomatoid papulosis an d its characteristic clinical features so that this disorder is accura tely diagnosed and so that unnecessary and potentially hazardous treat ment is avoided.