Abstract：
In this case report, we describe an uncommon case of neuroendocrine cancer of unknown origin began with cauda equina syndrome in a patient affected by Paget disease of bone (PDB). A 76-year-old man with diagnosis of PDB, without history of pain or bone deformity, developed sudden severe low back pain. Bone alkaline phosphatase was increased and MRI and whole-body scintigraphy confirmed the localization of the disease at the third vertebra of the lumbar spine. Treatment with Neridronic Acid was started, but after only 2 weeks of therapy anuria and bowel occlusion occurred together with lower limb weakness and walking impairment. Cauda equina syndrome consequent to spinal stenosis at the level of L2-L3 was diagnosed after admission to Emergency Department and the patient underwent neurosurgery for spinal medulla decompression. The histologic results showed a complete subversion of bone structure in neoplastic tissue, consistent with metastatic neuroendocrine carcinoma of unknown origin. In conclusion, low back pain in the elderly may require deep investigation to individuate rare diseases. In asymptomatic patients with apparently stable PDB, the sudden appearance of pain or neurologic symptoms may alert the clinician for the possibility of other superimposing diseases, like bone metastases.
摘要：
在这个案例报告中,我们描述了一例罕见的原因不明的神经内分泌癌,起病于马尾神经综合征,患者患有Paget骨病(PDB).一名76岁的男子诊断为PDB，没有疼痛或骨畸形史，突然出现严重的腰痛。骨碱性磷酸酶升高，MRI和全身闪烁显像证实了该疾病在腰椎第三椎骨的定位。开始用神经酸治疗，但在治疗仅2周后，出现无尿和肠闭塞，并伴有下肢无力和步行障碍。入院后诊断为L2-L3水平的脊髓狭窄导致的马尾综合征，患者接受了神经外科手术以进行脊髓减压术。组织学结果显示肿瘤组织的骨结构完全颠覆，与未知来源的转移性神经内分泌癌一致。总之,老年人的腰背痛可能需要深入研究，以个体化罕见疾病。在PDB明显稳定的无症状患者中，疼痛或神经症状的突然出现可能提醒临床医生其他叠加疾病的可能性，比如骨转移.
