Dermal monocytic sarcoma/monoblastic tumour: report of two cases of acute monocytic leukemia with initial dermal manifestations only

The clinical and pathological findings in 2 patients with acute monocytic leukemia (AMOL) presenting initially as multiple monoblastic tumours of the skin (monocytic sarcoma) were reviewed. The skin biopsies were originally interpreted as malignant lymphoma and the diagnosis of AMOL was established when overt bone marrow and/or peripheral blood involvement was detected. The time interval from initial skin biopsy to either blood or bone marrow involvement by AMOL was 2 and 18 mth. After diagnosis of extracutaneous dissemination, survival was less than 1 mth. Cytochemistry, immunohistochemistry and electron microscopy can aid in the diagnosis of a monocytic sarcoma. Generally, the most practical way to confirm the diagnosis, in everyday practice, on fixed paraffin-embedded tissues is the demonstration of alpha-1-antitrypsin (A1AT) and/or lysozyme by the immunoperoxidase technique.