Spinous Process Osteochondroma as a Rare Cause of Lumbar Pain

Abstract

We present a case of a 5th Lumbar Vertebra (L5) spinous process osteochondroma as a rare cause of lumbar pain in an old patient. A 70-year-old male presented with progressive and disabling lower lumbar pain. Tenderness over the central and left paraspinal area of the lower lumbar region and a palpable mass were evident. CT scan showed a mass arising from the spinous process of L5. Marginal resection of the tumor was performed through a posterior approach. The histological study revealed an osteochondroma. After surgery, pain was completely relieved. After one year there was no evidence of local recurrence or symptoms. Osteochondromas rarely involve the spine, but when they do symptoms like pain, radiculopathy/myelopathy, or cosmetic deformity may occur. The imagiologic exam of election for diagnosis is CT scan. When symptomatic the treatment of choice is surgical resection. The most concerning complication of osteochondromas is malignant transformation, a rare event.

Figure 1

CT scan. Axial view showing a well-limited mass with a cartilage cap arising from the spinous process of L5 lateralized to the left (arrow).

Figure 2

(a) Intraoperative picture showing a lumbar spine midline approach, exposing the tumor in situ in contiguous to the spinous process of L5 causing adjacent left paraspinal muscular compression. (b) Intraoperative picture of the resected tumor with an approximately 7 cm axis-length.

Figure 3

(a) Hematoxylin-eosin stain, original magnification ×2.5, and (b) Hematoxylin-eosin stain, original magnification ×10. Junction of cartilage cap and underlying bone without atypia and resemblance to an epiphyseal plate with enchondral ossification.