Extensive Bone Lesions and Skin Lesions Revealing an Acute Transformation of an Extramedullary Chronic Myeloid Leukemia

Extramedullary blast transformation as the initial presentation of Chronic Myeloid Leukemia with bone marrow remaining in the chronic phase is an unusual event. We report the case of a 30-year-old with chronic CML at the medullary level and an acute transformation revealed by extensive bone lyses and skin lesions. A 30-year-old man had cutaneous nodules, functional impotence and paresis. Radiological investigations revealed osteolytic lesions of the right humeral head, right clavicle, ribs, C5 and C7 vertebrae with medullary compression. Anatomo-pathological study and immunohistochemistry of nodules and osteolytic lesions resulted in granulocytic sarcoma with CD10 +, CD34 +, CD13 +, CD33 +, CD117 and MPO positive. The myelogram was in favor of chronic phase CML. He was put on imatinib, the chemotherapy could not be started because his condition was impaired and he dies by metabolic disorder. The acute transformation of chronic phase CML into extra marrow remains unusual. The care is a real challenge hence the need for consensual recommendations