Intracranial Myeloid Sarcoma as the First Manifestation of Acute Monoblastic Leukemia.

Background Myeloid sarcoma, also called granulocytic sarcoma, extramedullary myeloid tumor, or chloroma, is a manifestation of a myeloid neoplasm. These tumors can develop in various anatomical sites, including the central nervous system, presenting as an extra-axial tumor affecting the meninges or the ependyma. Diagnosis is challenging due to its resemblance to other intracranial tumors such as meningiomas. Case Description We present the case of a 17-year-old male with intermittent left frontotemporal headache, diplopia during horizontal gaze, and proptosis of the left eye. During the imaging evaluation, an extra-axial tumor was observed, suggesting a meningothelial lesion of the left sphenoid wing. The patient had no previous hematological disease. Tumor resection was performed using an orbitozygomatic approach. After 2 months, the patient had recurrence of the lesion associated with spontaneous epistaxis and leucocytosis and thrombocytopenia. Bone marrow aspirate biopsy and histopathology results were consistent with myeloid sarcoma. Conclusion Intracranial myeloid sarcomas mimic meningiomas, metastases, lymphomas, and even Ewing's sarcoma, making it difficult to suspect myeloid sarcoma in a patient without prior hematologic disease. Surgery aids in diagnosis through biopsy or reduces the volume effect that could cause neurological deficit.