RESUMO
BACKGROUND AND OBJECTIVES: Molecular events that precede transformations from lymphomatoid palulosis (LyP) to mycosis fungoides (MF) or to cutaneous anaplastic large cell lymphoma (ALCL) in the CD 30(+) cutaneous lymphoproliferative diseases (LPDs) are not known. Altered p(53) gene may be responsible since overexpression of the p(53) gene product has been reported in higher, but not in lower grades of cutaneous lymphomas. Expression of the anaplastic lymphoma kinase (ALK) gene product has also been described as an important prognostic indicator in ALCL. ALK positive systemic nodal ALCL are associated with a good prognosis. However, primary cutaneous ALCL that are ALK negative have a better overall survival. The current study was done to see if mutated p(53) gene or ALK reactivity were poor prognostic indicators in those patients with CD 30(+) cutaneous LPD who showed progression of the disease. METHODS: Mutations of the p(53) gene and expression of the ALK gene product were analysed in 36 patients (23 of LyP and 13 of CD30(+) cutaneous ALCL). Follow up data were available up till 5 yr in all patients. RESULTS: Clinical progression or histological transformation in sequential biopsy specimens was found in 9 of 36 patients. Transformation occurred in 5 patients (4 from LyP to ALCL and 1 from MF to ALCL) and clinical progression in 4 patients with ALCL. Mutations of the p(53) gene were found in two biopsy specimens of LyP. ALK gene products were not detected in any of the biopsy specimens of LyP and primary cutaneous ALCL. INTERPRETATION AND CONCLUSION: Although 9 of 36 patients with cutaneous CD30(+) LPDs had progression of their disease, neither mutations of the p(53) gene nor ALK immunoreactivity were found in any of these biopsies. The two cases of LyP that had mutated p(53) gene in their biopsy specimens showed no progression of their disease in the 5 yr follow up period. It appears that these molecular events may not play any significant role in the pathogenesis, progression or transformation of cutaneous CD30(+) LPD.