Cutaneous promyelocytic sarcoma at sites of Vascular access and marrow aspiration. A characteristic localization of chloromas in acute promyelocytic leukemia?

Extramedullary disease (EMD) is a rare clinical event in acute promyelocyti c leukemia (APL). Although the skin is involved in half of the reported EMD cases, the occurrence of cutaneous promyelocytic sarcoma (PS) has been des cribed very rarely. We report here three cases of PS which have the peculia rity of appearing at sites of punctures for arterial and venous blood and m arrow samples (sternal manubrium, antecubital fossa, wrist over the radial artery pulse, catheter insertion scar). At presentation, all patients had h yperleukocytosis and a morphologic diagnosis of microgranular acute promyel ocytic leukemia variant confirmed at the genetic level by demonstration of the specific chromosomal translocation t(15;17). A BCR3 type PML/RAR alpha transcript was documented in the two patients for whom diagnostic RT-PCR wa s available. Patients had morphologic bone marrow remission at the time the PS appeared. A predilection for the development of cutaneous PS at sites o f previous vascular damage has been noted, but the pathogenesis remains lar gely unknown. A potential role for all-trans retinoic acid has been advocat ed, although one of the three patients in our series had received no ATRA. A review of the literature revealed six similar cases and hyperleukocytosis at diagnosis was a consistent finding in all of them. A careful physical e xamination of these particular sites in the follow-up of patients at risk, as well as cutaneous biopsy and laboratory examination of suspected lesions are strongly recommended. (C) 2000, Ferrata Storti Foundation.