Original article CD561hematological neoplasms presenting in the skin: a retrospective analysis of 23 new cases and 130 cases from the literature

Background: The aim of this study was to define prognostic parameters and guidelines for diagnosis and treatment for CD56+ hematological neoplasms with first presentation in the skin. Patients and methods: The study group included 153 cases (23 new and 130 from the literature). According to the World Health Organization classification, the group included 15 nasal and 38 nasaltype natural killer (NK)/T-cell lymphomas, 63 blastic NK-cell lymphomas, 14 cutaneous CD30+ lymphoproliferations, 10 cases of myeloid leukemia, six cases of subcutaneous panniculitis-like T-cell lymphoma (SCPLTCL) and seven peripheral T-cell lymphomas, unspecified. Results: In general, these CD56+ hematological neoplasms had a poor prognosis, with only 27% of patients alive after a median follow-up of 12 months. The median survival was 13 months. Nasal and nasal-type NK/T-cell lymphomas and CD56+ SCPLTCL had the worst prognosis, with a median survival of 5, 6 and 5 months, respectively. Only nasal-type NK/T-cell lymphomas presenting with only skin lesions had a somewhat better prognosis (median survival 27 months). In blastic NK-cell lymphomas (median survival 14 months), age <_40 years, aggressive treatment with acute leukemia protocols and high TdT expression were associated with a more favorable prognosis. Striking similarities in histology, immunophenotype, clinical presentation and clinical behavior were found between blastic NK-cell lymphomas and CD56+ myeloid leukemias. Conclusions: CD56+ hematological neoplasms presenting in the skin have a poor prognosis, except for primary cutaneous CD30+ lymphoproliferations. The striking similarities between blastic NK-cell lymphomas and CD56+ myeloid leukemias presenting in the skin provide a rationale to treat these patients with more aggressive regimens, rather than with CHOP(-like) regimens and radiotherapy, which have proven to be inadequate therapies for this neoplasm.