Intramedullary spinal cord metastasis

Intramedullary spinal cord metastasis.

Demographics of affected patients reflect those of the underlying primary malignancy but over all the mean age of presentation is 55 years ¹⁾. They represent 8.5% of central nervous system metastases and account for 5% of all intramedullary lesions.

Breast cancer accounts for approximately one-third of all cancers in females. Approximately 8.5 % of all central nervous system metastases are located in the spinal cord. These patients have rapidly progressing neurological deficits and require immediate examination. The aim of surgery is decompression of neural tissue and histological evaluation of the tumor.

Intramedullary spinal cord metastasis most commonly occurs in the setting of advanced disease and only rarely is the first presentation of malignancy ²⁾.

In contrast to the long duration of symptoms that are typical of primary intramedullary spinal neoplasms, up to 75% of patients with a spinal cord metastasis have symptoms for less than one month before diagnosis ³⁾.

The most common presenting symptom is motor weakness. Other common presenting features are pain, bowel or bladder dysfunction, paraesthesia, or a rapid decline in neurological status in elderly patients ⁴⁾.

Lung cancer accounts for ~50% of cases ⁵⁾. Other primary malignancies are: breast cancer, lymphoma, leukemia, malignant melanoma, renal cell cancer, colorectal cancer, cholangiocarcinoma 9, pancreatic neuroendocrine tumor 10, ovarian carcinoma 11, prostate carcinoma 12, gastric adenocarcinoma 13 , uterine leiomyosarcoma (rare) 14, esophageal cancer 15, carcinoma of the uterine cervix 16, thyroid carcinoma 17, bladder carcinoma 18, salivary ductal carcinoma of the parotid gland 19.

One-third of patients have concomitant cerebral metastases and 25% have leptomeningeal metastases 5.

Despite their rarity, these lesions are important to the radiologist because magnetic resonance (MR) imaging is the preoperative study of choice to narrow the differential diagnosis and guide surgical resection. On contrast materialenhanced MR images, intramedullary spinal tumors almost always manifest as expansion of the spinal cord and show enhancement. Syringohydromyelia and cystic lesions are frequently associated with intramedullary tumors. Nontumoral cysts tend to be located at the poles of the tumors and do not enhance on contrast-enhanced MR images, whereas cysts within the substance of the tumor are considered tumoral cysts and typically demonstrate peripheral enhancement. Spinal cord ependymomas are the most common type in adults, and cord astrocytomas are most common in children. Both entities constitute up to 70% of all intramedullary neoplasms. A central location within the spinal cord, presence of a cleavage plane, and intense homogeneous enhancement are imaging features that favor an ependymoma. Intramedullary astrocytomas are usually eccentrically located within the cord, are ill defined, and have patchy enhancement after intravenous contrast material administration. Even with these characteristics, it may not be possible to differentiate these two entities on the basis of imaging features alone. Cord hemangioblastomas are the third most common type of intramedullary spinal tumor. Gangliogliomas commonly extend over more than eight vertebral segments. Paragangliomas and primitive neuroectodermal tumors have an affinity for the filum terminale and cauda equina. Other spinal cord tumors include metastatic disease, which is characterized by prominent cord edema for the size of the enhancing portion, and primary lymphoma ⁶⁾

Schiff and O'Neill BP reviewed records retrospectively from 1980 to 1993 to identify patients with histologically confirmed systemic cancer, clinical features of myelopathy, and either tissue-proven ISCM or abnormal neuroimaging findings consistent with ISCM. We identified 40 patients who fulfilled these criteria. In nine, ISCM was the initial presentation of cancer. Nineteen patients had lung primaries (small cell in 12). Twenty-one patients had pain, 35 had demonstrable sensory loss, 37 had weakness, and 25 had urinary incontinence at presentation. Nine patients had true Brown-Séquard syndrome and nine others had pseudo-Brown-Séquard syndrome. Median duration of symptoms at diagnosis was 28 days (range 3 days to 18 months). Thirteen patients had prior brain metastasis, nine had brain metastasis simultaneous with ISCM, and one had brain metastasis after ISCM; 11 had concomitant leptomeningeal metastases. Spinal magnetic resonance findings were abnormal in 30/30 patients, myelographic results were abnormal in 16/20, and eight had pathologic confirmation of ISCM. Thirty-five patients had radiotherapy and five had surgery; four were untreated or treated elsewhere. Median survival was 4 months for patients receiving radiotherapy and 2 months for patients not receiving radiotherapy. Eleven patients survived > 6 months. Twenty-three were ambulatory at ISCM diagnosis, and 21 were ambulatory at letest follow-up. We conclude that ISCM as the initial presentation of malignancy is not rare, and hemicord syndromes occur frequently. Although long-term survival is poor, treatment preserves ambulation in most patients still ambulatory at diagnosis. Focal radiotherapy is indicated in most patients ⁷⁾.

Three cases presenting as focal mass lesions with minimal systemic evidence of cancer. Connolly et al. in 1996 presented the results in these patients and reviewed the literature in an effort to more optimally define both the natural course of this disease, as well as a potential subset of patients who might benefit from more aggressive treatment.

With the availability of more sensitive imaging techniques, these tumors are being diagnosed with increasing frequency. Magnetic resonance imaging is sensitive, but nonspecific, in distinguishing intramedullary spinal cord metastases from primary cord tumors. Urgent biopsy is often necessary prior to definitive treatment. Radiation with chemotherapy significantly prolongs survival. Radical subtotal resection may offer additional quality survival, especially in cases of metastatic melanoma with an occult primary.

Regardless of treatment, many patients survive less than 1 year. Intramedullary spinal cord metastasis is a devastating condition, but with appropriate diagnosis and aggressive treatment, selected patients may have substantially increased survival ⁸⁾.

A 43-year-old female patient with breast cancer for 8 years was admitted with complaints of weakness in both legs. Eight years ago, she received chemotherapy and radiotherapy. On her neurological examination, she had paraparesis (left lower extremity: 2/5, right lower extremity: 3/5) and urinary incontinence. Spinal MRI revealed a gadolinium enhancing intramedullary lesion. Pathologic examination of the lesion was consistent with breast carcinoma metastasis. The patient has been taken into radiotherapy. Spinal intramedullary metastasis of breast cancer is an extremely rare situation, but it has a high morbidity and mortality rate. Microsurgical resection is necessary for preservation or amelioration of neurological state and also for increased life expectancy and quality ⁹⁾.