Abstract
Abstract Background: The spine is not only the most frequent site of skeletal metastasis of a known carcinoma but it is also the most frequent site of bone metastasis of unknown primary tumor origin, however, most of the existing reports that analyzed the clinical features of patients who presented with skeletal metastasis of unknown origin have included cases of bone metastasis at any location. Objective: This study was conducted to analyze the clinical features, survival, and specific diagnostic implications in patients presented with spinal metastasis of unknown primary malignant tumor. Method: In this prospective study, 40 patients presented with spinal metastasis of unknown primary tumor origin to Mosul Oncology Hospital were followed up. Result: The primary malignant tumor was identified in (97.5%) of cases, lung cancer was the most frequently identified primary tumor (35%) followed by carcinoma of the breast (30%) and prostatic cancer (12.5%). We found that Computed tomography scan of the chest, abdomen, and pelvis were the most useful diagnostic modality to identify the primary malignant tumor and there was a significant difference in the overall survival of patients with different primary tumor sites, shorter survival time was observed for aggressive tumor like lung cancer compared to patients having less aggressive primary tumor like breast and prostatic cancer. Conclusion: Spinal metastasis of unknown primary carries a diagnostic challenge to the clinician, it is possible to detect the primary site in the majority of patients if we follow optimal diagnostic strategies. Detection of primary tumor site could help the clinician to provide the best therapeutic strategies.