DUSP22 GENE REARRANGEMENT IDENTIFIED IN BOTH SYSTEMIC ANAPLASTIC LARGE CELL LYMPHOMA AND LYMPHOMATOID PAPULOSIS IN A 78-YEAR-OLD WOMAN.

Summary: We report a case of a woman diagnosed with two rare conditions, systemic anaplastic large cell lymphoma (ALCL) and lymphomatoid papulosis (LyP), both of which demonstrated the same cytogenetic translocation involving DUSP22. Core needle biopsy findings of two enlarged axillary lymph nodes were diagnostic of ALK negative ALCL and, notably, FISH studies demonstrated a DUSP22 mutation. The patient was treated with BV-CHP, and during and after therapy she developed numerous skin papules; biopsies revealed a CD30+ lymphoproliferative disorder and a DUSP22 mutation was also present. These lesions were favored to be LyP rather than cutaneous ALCL and they regressed without treatment. DUSP22 is a tyrosine phosphatase expressed in various human tissues and is involved in T-cell mediated immunity and autoimmunity [1,2]. The DUSP22 rearrangement is found in less than 5% of cases of LyP and in less than 30% of ALCLs, where it portends a good prognosis [3]. Our report highlights that clonal cytogenetic abnormalities present in both a CD30+ systemic lymphoma and CD30+ lymphoproliferative disorder in the skin do not always represent aggressive cutaneous disease progression; clinical correlation is imperative in these cases.