Chronic subdural collection overlying an intra-axial hemorrhagic lesion in chronic myelomonocytic leukemia: special report and review of the literature.

: Chronic myelomonocytic leukaemia (CMML) is a clonal hematopoietic stem cell disorder characterized by the presence of an absolute monocytosis in the peripheral blood (>1 x 10/L) and the presence of myelodysplastic and myeloproliferative features in the bone marrow. Involvement of the central nervous system (CNS) is uncommon in CMML.: Herein described is a case report of a CMML patient who presents with symptomatic chronic subdural collection overlying a haemorrhagic brain lesion, along with diffuse dural infiltration, after two cycles of azacytidine. Surgical intervention was performed to alleviate the mass effect on the brain, and obtain a tissue sample for diagnosis. Histopathological report confirmed brain infiltration with myeloid leukemic cells.: Despite its rarity, cerebral dissemination should be considered even in patients with CMML. A multidisciplinary approach, lead by a hematologist, is mandatory in order to correct the underlying haematological disorder, with specific attention to the coagulation profile. Surgical intervention is necessary for symptomatic patients, and should be performed once an improvement of clinical conditions has been achieved. Despite appropriate surgical and medical therapy, the prognosis remains poor with high risk of perioperative complications, such as rebleeding, and progressive systemic involvement.