CS predominantly arises in elderly patients (range, 30–70 years) with a peak incidence in the sixth decade [14]. CSs can occur in all bones, but rarely involve the spine: the prevalence is reported between 6.5 and 12% in the mobile spine and approximately 2–5% within the sacrum [3, 4, 15–17]. Considering only the spine, roughly 19–20% of CSs arise in the cervical spine, 30–48% in the thoracic spine, 20–33% in the lumbar spine, and 16–20% in the sacrum [4, 15, 18].

Primary CS is usually eccentric and involves the proximal part of the sacrum, destroying the sacroiliac joint [4, 5]. Secondary CS can develop from benign lesions most frequently in diffuse disease such as enchondromatosis, Maffuci syndrome, or Ollier’s disease [19].

Clinical occurrence of CS varies widely. Tumor remains clinically silent for a long time before the patients finally experience pain in the area of the lesion, or pain can be present for weeks to years. Swelling and sacral mass at presentation, as well as neurological symptoms, are associated with large tumors. Radicular symptoms are seen in roughly 24% of patients [18]. In huge tumors, skin ulceration and hemoserous discharge may be observed [7].

An adequate staging of sacral CS includes complete imaging assessment and histologic evaluation. CS presents radiographically as a mixed lytic with typical dense areas of calcifications in the extraosseous soft tissue component of the tumor [20, 21]. CT scan and MRI show the same appearance of CS of the extremities. Additional imaging studies include a CT scan of the chest, abdomen, and pelvis. Bone scan could be useful in distinguishing central to peripheral CS [21] as well as for early diagnosis of silent lesions in the rest of the spinal column. The appropriate imaging studies allow for a better understanding of the extent of the lesion as well as a differential diagnosis, but biopsy is a key diagnostic method for sacral CS and should be carefully planned according to the definitive surgery.

Histologically, CSs show abundant blue-gray cartilage matrix production and irregularly shaped cartilage lobules varying in size and shape. These lobules may be separated by fibrous bands or permeate bony trabeculae. Mitotic figures, hypercellularity, mild to moderate nuclear atypia, double-nucleated cells, and myxoid changes in the stroma can be observed [15, 16, 19, 20, 22]. CSs are pathologically classified as conventional (80–85%), clear cell (1–2%), myxoid (8–10%), mesenchymal (3–10%), and dedifferentiated (5–10%) subtype [19, 22]. Moreover, they are grade on a scale of 1 (low grade) to 3 (high grade) based on nuclear size, nuclear staining, and cellularity [22, 23].

Sacral CSs are rare and thus difficult to manage. In general, surgery is the most accredited treatment modality, as no chemotherapy has been demonstrated to be effective against CS as well as conventional radiotherapy [5, 6, 15, 16, 18]. Resection with wide margins is the procedure of choice in sacral CS, since this is the most effective way of reducing recurrence rate [6].