====== ๐Ÿง  Intramedullary Metastases ====== ๐Ÿ“Œ Definition: Metastatic tumors that invade the spinal cord parenchyma (intramedullary compartment), often leading to rapid neurologic deterioration. ๐Ÿ“Š Epidemiology: Very rare: <3% of CNS metastases. More common in middle-aged to elderly patients. Often present in patients with widespread systemic cancer. ๐Ÿ” Common Primary Tumors: Lung cancer (esp. small-cell and adenocarcinoma) โ€“ most frequent. Breast cancer Renal cell carcinoma Lymphoma/leukemia Melanoma Occasionally from colorectal or thyroid cancers. ๐Ÿงฌ Pathophysiology: Spread via hematogenous route or CSF dissemination. Often associated with leptomeningeal carcinomatosis. Most frequently involve the cervical and thoracic cord. โš ๏ธ Clinical Presentation: Rapidly progressive myelopathy. Motor weakness, sensory loss, and sphincter dysfunction. Radicular pain may precede neurological deficits. Symptoms evolve faster than in primary spinal cord tumors. ๐Ÿงช Diagnosis: MRI with contrast: gold standard (shows enhancing intramedullary lesion, possible edema). CSF analysis: may show malignant cells if leptomeningeal spread. Biopsy: rarely performed unless primary is unknown or atypical imaging. ๐Ÿง  Differential Diagnosis: Intramedullary glioma (astrocytoma, ependymoma) Demyelinating lesions Vascular malformations Infectious myelitis Radiation myelopathy ๐Ÿฉบ Treatment: Steroids: to reduce edema and inflammation. Radiotherapy: primary modality, often palliative. Surgery: rarely indicated, only if diagnosis uncertain or mass effect. Systemic therapy: if chemosensitive tumor and systemic disease present. ๐Ÿ“‰ Prognosis: Poor, median survival โ‰ˆ 3โ€“6 months. Prognosis depends on systemic disease control and neurological status at diagnosis.