Although intervertebral disc degeneration usually occurs in the natural course of alkaptonuria, detection of the disease by black disc material in a patient without any other sign of alkaptonuria is an extremely rare condition. The authors report a 45-year-old previously healthy female patient who was operated on for prolapsed lumbar disc herniation, and in whom the nucleus pulposus was discovered to be black intraoperatively. The alkaptonuria was diagnosed after histopathological examination of the black disc material. Elevated urinary concentration of homogentisic acid confirmed the diagnosis.

We report a case of squamous cell carcinoma originated from a sacrococcygeal tailgut cyst in a 73-year-old female patient. Tailgut cysts are generally multilocal and have a layer of either columnar, squamous or transitional epithelium, or a combination of these. This case was treated with surgical excision and radiotherapy. Cancer presentation of a congenital abnormality in old age is a rare entity. This report is the first case of squamous cell carcinoma developing in a tailgut cyst without any synchronization, as an isolated (pure) pathology.

Although spinal osteochondromas can cause various clinical signs, the spinal cord or nerve root compression by solitary lumbar osteochondromas are rare clinical entities. We present a 62-year-old female patient with lower-back pain, progressive left leg paresis, numbness on the both lower extremities and urinary incontinence. The patient's clinical picture made us suspect the possibility of cauda equina syndrome. Radiological examination revealed a lesion originating from the left inferior articular facet of the second lumbar vertebrae. Urgent surgical decompression was performed and the lesion was removed totally. Histopathological examination confirmed the diagnosis of benign osteochondroma.

Although osteochondroma is the most common benign bone tumor, the lumbar spine is anuncommon localization for solitary osteochondroma. Solitary lumbar osteochondromas rarely affect the neurological structures, because most of the lesions grow out of the spinal canal. We report a 48-year-old patient suffering from right foot-drop due to acute compression of right L4 nerve root by a lesion expanding into the spinal canal, originating from the right inferior articular facet of the third lumbar vertebrae. The symptoms improved after surgical removal of the lesion and histopathological examination of the lesion confirmed the diagnosis of osteochondroma. To the best of our knowledge, this is a unique case report in the literature. KeywoRds: Osteochondroma, Foot-drop, Lumbar spine, Differential diagnosis ÖZOsteokondroma en yaygın iyi huylu kemik tümörü olmasına rağmen, lomber omurga soliter osteokondrom için alışılmadık bir lokalizasyondur. Soliter lomber osteokondromlar nörolojik yapıları nadiren etkilerler, çünkü bu lezyonların birçoğu spinal kanal dışına doğru gelişirler. Biz üçüncü lomber vertebranın inferior artiküler fasetinden köken alan ve spinal kanal içine uzanım gösteren lezyonun sağ L4 sinir kökünü akut kompresyonu sonucu sağda düşük ayak yakınması bulunan 48 yaşındaki hastayı rapor ettik. Lezyonun cerrahi olarak çıkarılması sonrası semptomlar iyileşme gösterdi ve lezyonun histopatolojik inceleme sonucu osteokondroma ile uyumlu geldi. Bildiğimiz kadarıyla, bu literatürdeki bu şekildeki tek olgudur.