Osteochondroma Arising From the Inferior Articular Process of the Lumbar Spine in a Geriatric Patient: A Case Report and Literature Review.

OBJECTIVE: Spinal osteochondromas are rare, and approximately less than 5% occur as spinal lesions. We report the case of a solitary osteochondroma of the spine and review and update the literature on spinal osteochondroma, including surgical treatment and subsequent results. CASE DESCRIPTION: A 73-year-old female patient complained of a 10-year history of back pain and a 4-year history of right-side lower extremity radiating pain with paresthesia. Computed tomography and magnetic resonance imaging (MRI) revealed a bony mass arising from the inferior articular process (IAP) of L3, presenting with features of compressive spinal stenosis at the L3-L4 level. The treatment strategy included the complete marginal excision of the lesion through the posterior approach, as well as complete decompression of the spinal canal and nerve roots. The patient's symptoms resolved after surgery, and histopathological examination identified the lesion as an osteochondroma. REVIEW
RESULTS: This review study included 168 solitary osteochondroma cases. The most commonly involved spinal level was cervical (51.8%), and the most frequent spinal anatomic column involved was the posterior column (70.8%). Radiculopathy accounted for 30.3% of all cases, myelopathy accounted for 31.0%, and 7.7% exhibited both symptoms simultaneously. The recurrence rate was 6.0%.
CONCLUSION: Computed tomography and MRI can effectively diagnose spinal osteochondroma, and surgical treatment can effectively improve clinical outcomes. In almost all symptomatic cases, the best treatment is marginal excision of the tumor. Complete resection of the cartilaginous cap of the tumor is especially important to prevent recurrence.

Introduction

Among benign bone tumors, osteochondromas are a relatively common one. Osteochondroma is also known as osteochondrogenic exostosis or exostosis, which can be solitary or multiple. Osteochondromas usually occur in the long bones in the appendicular skeleton, which involve the metaphyseal or diametaphyseal region. Spinal osteochondromas are rare, and approximately less than 5% occur as spinal lesions. They are usually asymptomatic; however, symptomatic myelopathy, progressive radiating pain, or both, if not diagnosed and treated early, may lead to serious neurological sequelae because it poses a threat to the spinal cord and surrounding vital structures.[4,5]

Here, we report a case of a solitary lumbar osteochondroma with neurological symptoms and conduct a review of the literature on the subject from 2004.

Case Report

A 73-year-old female presented with a 10-year history of back pain and a 4-year history of right-side lower extremity radiating pain with paresthesia. Neurological intermittent claudication was 100 m, but no abnormalities in urination and defecation were observed. The patient had no prior history of bone masses or other tumors. Computed tomography and magnetic resonance imaging (MRI) showed an abnormal bony mass arising from the right-side inferior articular process (IAP) of L3 that projected into the spinal canal, resulting in marked spinal canal stenosis (Figures 1 and 2).

Figure 1.

Preoperative CT images. An abnormal bony mass arising from the right-side inferior articular process of L3 that projected into the spinal canal, resulting in marked spinal canal stenosis.

Figure 2.

A-D, preoperative MRI images; E and F, postoperative MRI.

A posterior median incision centered on L3 was made, the skin and subcutaneous tissue were incised, and the sacral spinal muscles on both sides were bluntly stripped to expose the L3 and L4 spinous processes and both sides of the lamina. The pedicle screws were inserted at the L3 and L4 pedicles. Then, the right portion of the lamina and IAP were removed to visualize the IAP and the 1.5 cm × 1.5 cm bony protrusion in front of the lamina (Figure 3). The protrusion was covered with white cartilage, and the ligamentum flavum, which was hypertrophic, was removed. A check for active bleeding was subsequently performed. The incision was closed layer by layer, and a drainage tube was placed. Finally, the wound was covered with a sterile dressing.

Figure 3.

Overall architecture of the lesion.

Histopathological examination of the resected tissue revealed a bony lesion with a three-layer structure with clear boundaries: a thickened fibrous capsule on the surface, a hyperplastic cartilage tissue in the middle layer, chondrified bone tissue and cancellous bone in the inner layer, and calcification in some areas; the above descriptions typical of an osteochondroma (Figure 4).

Figure 4.

Histopathological examination.

No adverse events were encountered peri- and postoperatively. The patient demonstrated immediate relief from back pain and right leg radiating pain. On postoperative day 3, an MRI scan showed no residual tumor and no compression of the spinal canal (Figure 2E and F).

Discussion

To search for relevant articles on solitary osteochondromas and spinal lesions, we conducted a comprehensive literature search on the database, including PubMed, Embase, and Cochrane Library for papers published from 2004 to August 2020. English language filters were applied, and standard searches were performed with the keywords: “osteochondroma” AND “spinal.” Titles and abstracts from all the reports identified were examined independently by 2 reviewers (G.X.L. and H.J.W.), and the full texts of suitable studies were retrieved. In addition, the reference lists of the selected articles and previous similar meta-analyses on solitary spinal osteochondromas were manually researched. In cases where disagreements could not be resolved, in-depth discussions were conducted, and ultimately decided upon by the senior author. The exclusion criteria were literature reviews, cases of other osteochondromas, and reports without details of the cases.

On reviewing the literature, a total of 207 articles were published from 2004 to August 2020, of which 92 articles[4-95] (168 cases) met the inclusion criteria (Figure 5). The demographic data are shown in Table 1. The review included 100 male patients and 68 female patients. The mean age was 35.3 years (range from 2 to 83 years). The most frequent spinal level involved was cervical in 86 (51.8%) of the cases, followed by lumbar with 42 (25.0%), thoracic with 34 (20.2%), sacral with 14 (8.3%), and coccyx with 2 (1.2%). Among the 168 cases, 11 cases involved the vertebral junction, 5 involved the cervicothoracic junction, 2 the thoracolumbar, and 4 the lumbosacral. The most common spinal anatomic column involved was the posterior column with 119 cases (70.8%), followed by the anterior column with 22 (13.1%). In 16.1% of cases, the spinal anatomic column was not reported. Radiculopathy accounted for 30.3% of cases and myelopathy for 31.0%. In 7.7% of cases, both symptoms occurred simultaneously. Only 10 (6.0%) cases had recurrence after surgery. All 168 cases of solitary spinal osteochondromas are listed in Table 2. Among them, a total of 145 patients underwent surgery, and the clinical symptoms of 123 patients were improved. Two cases presented with worsening symptoms after surgery.

Figure 5.

A flow chart of the review study.

Table 1.

Demographic Data of Spinal Solitary Osteochondroma of the 168 Cases.

	n = 168 (%)
Sex; male: female	100:68
Age (years)	35.3 (range of 2–83 years)
Tumor in spinal level
Cervical	87 (51.8)
Thoracic	34 (20.2)
Lumbar	42 (25.0)
Sacral	14 (8.3)
Coccyx	2 (1.2)
Involved spinal column
Anterior	22 (13.1)
Posterior	119 (70.8)
Not reported	27 (16.1)
Symptoms
Radiculopathy	51 (30.3)
Myelopathy	52 (31.0)
Both	13 (7.7)
Not reported	52 (31.0)
Recurrence
Yes	10 (6.0)
No	111 (66.1)
Not reported	47 (27.9)

Table 2.

Reviewed Cases in Literature.

Author	Year	Age	Gender	Level	Location	Presentation	Treatment	Clinical outcomes
Shigekiyo et al 4	2020	61	Male	L4-L5	L4 lamina	Symptomatic	Complete excision	Complete resolution
	2020	62	Male	L4-L5	Right L4-5 facet joint	Symptomatic	Complete excision	Near complete resolution
Acharya et al 5	2020	52	Male	T10	Posterior arch of T10	Symptomatic	Complete excision	Complete resolution
Yudistira et al 6	2020	76	Female	C1-C2	Posterior arch of C1 and lamina of C2	Symptomatic	Complete excision	Complete resolution
Fowler et al 7	2020	32	Male	C4	Inner margin of the C4 lamina	Symptomatic	Complete excision	Complete resolution
Rajakulasingam et al 12	2020	83	Female	C7	2 (18.2%)-vertebral body, 9 (81.8%) posterior elements-3 lamina, 2 transverse process, 2 facet joint, 1 spinous process, 1 pedicle	Symptomatic	N/A	Nonsurgical
	2020	33	Male	C7		Symptomatic	N/A	Nonsurgical
	2020	54	Male	C7		Symptomatic	N/A	Nonsurgical
	2020	74	Female	C4		Symptomatic	N/A	Excised
	2020	40	Female	C3		Symptomatic	N/A	Excised
	2020	34	Female	C3		Symptomatic	N/A	Excised
	2020	57	Female	C2		Symptomatic	N/A	Nonsurgical
	2020	17	Male	C6		Symptomatic	N/A	Excised
	2020	54	Female	C5		Symptomatic	N/A	Excised
	2020	63	Male	C5		Symptomatic	N/A	Biopsy
	2020	31	Female	C5		Symptomatic	N/A	Excised
Chang et al 8	2019	63	Male	C4-C6	Left C5 transverse	Symptomatic	Complete excision	Complete resolution
Gigi et al 9	2019	9	Female	C1	Left lamina of C1	Symptomatic	Complete excision	Complete resolution
	2019	12	Female	C3-C4	C3 lamina	Symptomatic	Complete excision	Near complete resolution
	2019	13	Male	C2 C4	C2 lamina on the right and the C4 lamina on the left	Symptomatic	Complete excision	Near complete resolution
Hari et al 10	2019	60	Male	C5-C7	Vertebral body	Symptomatic	Laminectomy	Near complete resolution
Das et al 11	2019	2	Female	Coccyx	Coccyx	Asymptomatic	Complete excision	Complete resolution
Tripathy et al 16	2019	19	Female	S2-S3	Lamina	Symptomatic	Complete excision	Complete resolution
Akhaddar et al 13	2018	34	Male	C3	Posterior elements	Symptomatic	Complete excision	Near complete resolution
Du et al 17	2018	16	Female	T3-T4	Left pedicle of T4	Symptomatic	Complete excision	Complete resolution
Ganesh et al 14	2018	9	Male	T3-T4	Posterior elements	Symptomatic	Complete excision	Near complete resolution
Garg et al 19	2018	32	Male	C4	Right transverse process and body of C4 vertebrae	Symptomatic	Complete excision	Complete resolution
Nakaya et al 21	2018	55	Male	L3-L4	Left L3/4 facet joint	Symptomatic	Complete excision	Complete resolution
Fukushi et al 18	2017	8	Female	C3	C3 spinous process	Symptomatic	Complete excision	Complete resolution
García-González et al 15	2017	8	Female	T3	T3 posterior wall	Symptomatic	Complete excision	Complete resolution
Raswan et al 20	2017	16	Male	C3	C3 posterior arch	Symptomatic	Complete excision	Complete resolution
Veeravagu et al 23	2017	22	Male	C3	Posterior elements	Symptomatic	Complete excision	Complete resolution
	2017	23	Female	C4		Symptomatic	Complete excision	Complete resolution
Sade et al 22	2016	15	Female	L3	L3 posterior elements	Symptomatic	Complete excision	Complete resolution
Sultan et al 24	2016	8	Male	C1	Posterior C1 arch	Symptomatic	Complete excision	Complete resolution
Pham et al 94	2016	17	Male	T9	Vertebral body	Symptomatic	Complete excision	Complete resolution
Zhang et al 25	2015	19	Female	C1	Posterior C2 arch	Symptomatic	Complete excision	Complete resolution
Hancock et al 26	2015	16	Female	L5-S1	Facet joints	Symptomatic	Complete excision	Complete resolution
Baruah et al 27	2015	21	Male	S3-S4	Sacrum	Asymptomatic	Complete excision	Complete resolution
Sciubba et al 28	2015	35	Female	C7	N/A	N/A	En bloc resection	N/A
	2015	48	Male	S1	N/A	N/A	En bloc resection	N/A
	2015	46	Male	C7	N/A	N/A	Intralesional excision	N/A
	2015	46	Female	T9-T10	N/A	N/A	Intralesional excision	N/A
	2015	61	Male	L2	N/A	N/A	Intralesional excision	N/A
	2015	65	Male	C3-T2	N/A	N/A	En bloc resection	N/A
	2015	48	Male	S1	N/A	N/A	En bloc resection	N/A
	2015	43	Female	C6-C7	N/A	N/A	En bloc resection	N/A
	2015	76	Female	T11-T12	N/A	N/A	Intralesional excision	N/A
	2015	21	Male	S1	N/A	N/A	En bloc resection	N/A
	2015	49	Female	C5-C7	N/A	N/A	Intralesional excision	N/A
	2015	17	Male	S1	N/A	N/A	En bloc resection	N/A
	2015	32	Male	L4-L5	N/A	N/A	Intralesional excision	N/A
	2015	60	Male	T12	N/A	N/A	Intralesional excision	N/A
	2015	68	Female	L2	N/A	N/A	Intralesional excision	N/A
	2015	13	Female	T1	N/A	N/A	En bloc resection	N/A
	2015	19	Male	L5	N/A	N/A	En bloc resection	N/A
	2015	38	Male	L4-L5	N/A	N/A	En bloc resection	N/A
	2015	20	Male	L5	N/A	N/A	En bloc resection	N/A
	2015	36	Female	T11-T12	N/A	N/A	En bloc resection	N/A
	2015	26	Male	C4-C5	N/A	N/A	Intralesional excision	N/A
	2015	33	Female	L1	N/A	N/A	En bloc resection	N/A
	2015	21	Male	T7	N/A	N/A	En bloc resection	N/A
	2015	18	Male	T1-T2	N/A	N/A	N/A	N/A
	2015	13	Male	L5-S3	N/A	N/A	En bloc resection	N/A
	2015	17	Female	C1-C3	N/A	N/A	Intralesional excision	N/A
	2015	2	Female	T8-T11	N/A	N/A	En bloc resection	N/A
Kim et al 29	2015	60	Female	C2	N/A	Symptomatic	Complete excision	N/A
Sade et al 30	2015	24	Female	L4	No	Symptomatic	N/A	N/A
Rymarczuk et al 31	2015	40	Male	L5	Right anteriosuperior endplate of L5	Symptomatic	Complete excision	Complete resolution
Fadili et al 32	2014	59	Male	C4	Posterior C4 arch	Symptomatic	Complete excision	Near complete resolution
Ramdasi et al 33	2014	28	Male	T2-T3	Posterior arch	Symptomatic	Laminectomy	Complete resolution
Akhaddar et al 34	2014	48	Male	C6	Posterior arch	Symptomatic	Complete excision	Complete resolution
Ogul et al 35	2014	24	Female	C3	Lamina	Symptomatic	N/A	N/A
Kuraishi et al 36	2014	57	Male	L4	Inferior articular process	Symptomatic	Laminectomy	Complete resolution
	2014	63	Female	S1	Superior articular process	Symptomatic	Hemilaminectomy	Complete resolution
	2014	48	Female	L4	Inferior articular process	Symptomatic	Hemilaminectomy near	Complete resolution
	2014	32	Male	L4	Inferior articular process	Symptomatic	Hemilaminectomy	Complete resolution
	2014	62	Male	L4	Inferior articular process	Symptomatic	Hemilaminectomy	Complete resolution
Pepa et al 37	2014	68	Male	C4-C5	Anterior arch	Symptomatic	Complete excision	Complete resolution
Sharma et al 38	2014	20	Male	C7-T1	Posterior arch	Asymptomatic	Complete excision	N/A
Ruivo et al 39	2014	68	Female	T9-L3	Posterior arch	Symptomatic	Complete excision	Complete resolution
Pourtaheri et al 40	2014	11	Male	L2-L4	Inferior articular process	Symptomatic	En bloc resection	Complete resolution
Huda et al 41	2014	14	Female	C5-C6	Transverse process	Asymptomatic	Total excision	Complete resolution
Sekharappa et al 42	2014	52	Male	C2-C6	Transverse process	Symptomatic	Laminectomy	Complete resolution
Zinna et al 43	2013	9	Male	C1-C2	Inner surface of C2 arch	Symptomatic	C2 hemilaminectomy, resection of posterior C1 arch	Complete resolution
Natale et al 44	2013	56	Female	L2	Lamina	Symptomatic	En bloc resection	Complete resolution
Gulati et al 45	2013	22	Male	C3-C4	Vertebrae and pedicles	N/A	N/A	N/A
Lin et al 46	2013	43	Male	L4	Spinous process	Symptomatic	Complete excision	Complete resolution
	2013	26	Male	C1-C2	Lateral mass	Symptomatic	Complete excision	Complete resolution
	2013	11	Male	T1	Laminar	Symptomatic	Laminectomy, complete excision	Complete resolution
	2013	60	Female	C1	Laminar	Symptomatic	Complete excision	Worsening of symptoms
	2013	34	Female	C1-C2	Laminar	Symptomatic	Laminectomy, complete excision	Complete resolution
	2013	17	Female	C1	Transverse process	Symptomatic	Complete excision	Complete resolution
	2013	63	Female	C5-C7	Lamina	Symptomatic	Complete excision	Complete resolution
	2013	17	Female	T6	Pedicle	Symptomatic	Laminectomy, complete excision	Complete resolution
	2013	49	Female	C2-C3	Vertebral body	Symptomatic	Laminectomy, complete excision	Worsening of symptoms
	2013	68	Female	L2	Lamina	Symptomatic	Laminectomy, complete excision	Complete resolution
	2013	56	Female	T5	Vertebral body	Symptomatic	Laminectomy, complete excision	Partial functional resolution
	2013	57	Female	C5	N/A	Symptomatic	Laminectomy, complete excision	Complete resolution
Mardi et al 47	2013	9	Male	T1	Vertebral body and posterior arch	Symptomatic	Partial resection near	Complete resolution
Wong et al 48	2013	65	Male	C2	Vertebral body	Symptomatic	Complete excision	Complete resolution
Mehrian et al 49	2013	19	Male	T9	Posterior arch	Symptomatic	Laminectomy	Complete resolution
Kahveci et al 50	2012	62	Female	L2	Inferior articular process	Symptomatic	Complete excision	Complete resolution
Strovski et al 51	2012	39	Male	L4	N/A	Symptomatic	N/A	N/A
Rahman et al 52	2012	16	Male	C1	Posterior arch	Symptomatic	Laminectomy near	Complete resolution
Kahveci et al 53	2012	48	Male	L3	Inferior articular process	Symptomatic	Hemilaminectomy, complete excision near	Complete resolution
Bonic et al 54	2012	21	Female	C5	Spinous process	Symptomatic	Laminectomy w/t en bloc resection	Complete resolution
Mudumba et al 55	2012	14	Male	C3	Lamina	Symptomatic	Laminectomy w/t en bloc resection	Complete resolution
Lee et al 56	2012	32	Male	C4-C5	Lamina and facet joint	Symptomatic	Hemilaminectomy near	Complete resolution
Er et al 57	2012	42	Female	C1	Lamina	Symptomatic	Laminectomy	Complete resolution
Okamoto et al 58	2011	69	Male	C7-T1	N/A	Symptomatic	Laminectomy	Complete resolution
Eap et al 59	2011	23	Male	C4	Posterior arch	Symptomatic	Laminectomy	Complete resolution
Volokhina et al 95	2011	26	Male	C2	Lamina	Symptomatic	Complete excision	Complete resolution
Reckelhoff et al 60	2010	24	Male	C4	Vertebral body	Symptomatic	Nonsurgical—spinal manipulation	Complete resolution
Gunay et al 61	2010	26	Male	L1	Spinous process	Symptomatic	Complete excision	Complete resolution
	2010	9	Male	C3-T1	Spinous process, posterior arch	Asymptomatic	Complete excision	Complete resolution
	2010	36	Female	T11-L1	Lamina	Symptomatic	Laminectomy, complete excision	Near complete resolution
	2010	65	Male	C4	Vertebral body	Symptomatic	Anterior excision, followed by anterior cervical fusion	Complete resolution
	2010	19	Male	C5-C6	Spinous process	Symptomatic	Complete excision	Complete resolution
	2010	32	Female	L3-L4	Lamina	Asymptomatic	Nonsurgical	Asymptomatic
Teka et al 62	2010	7	Male	Coccyx	Coccyx	Symptomatic	En bloc excision	Complete resolution
Miyakoshi et al 63	2010	58	Male	C1-C2	Spinous process	Symptomatic	En bloc excision	Complete resolution
Lotfinia et al 64	2010	29	Male	L4	Pedicle	Symptomatic	Laminectomy	Complete resolution
	2010	58	Male	L5	Vertebral body	Symptomatic	Laminectomy	Complete resolution
	2010	60	Male	C5	Lamina	Symptomatic	Hemilaminectomy	Complete resolution
	2010	34	Male	C5-C6	Lamina	Symptomatic	Laminectomy	Near complete recovery
	2010	55	Male	T9	Vertebral body	Symptomatic	Complete excision	Complete resolution
	2010	17	Male	L3	Inferior facet	Symptomatic	Hemilaminectomy	Complete resolution
	2010	34	Female	C7	Pedicle	Symptomatic	Hemilaminectomy near	Complete resolution
	2010	31	Male	T8	Superior facet	Symptomatic	Laminectomy	N/A
Chin et al 65	2010	54	Female	S1	Sacralala—anterior surface	Symptomatic	Complete excision	Complete resolution
Choi et al 66	2010	57	Female	L3	Lamina	Symptomatic	En bloc resection, laminectomy, facetectomy	Complete resolution
Yagi et al 67	2009	77	Female	C1	Posterior arch	Symptomatic	Hemilaminectomy w/t en bloc resection	Complete resolution
	2009	72	Male	L4	Inferior facet	Symptomatic	Marginal resection and facetectomy	Complete resolution
	2009	69	Male	L4-L5	Inferior facet	Symptomatic	Intraarticular injection, biopsy, and ablation of articular facet joint	Complete resolution
Xu et al 68	2009	38	Male	L5	Lamina	Symptomatic	Laminectomy	Complete resolution
Rao et al 69	2009	8	Female	C2-C6	Spinous process	Symptomatic	En bloc resection	Complete resolution
Wang et al 70	2009	16	Female	C1-C2	Vertebral body	Symptomatic	Complete excision	Complete resolution
Ding et al 71	2009	28	Male	T8	Transverse process	Symptomatic	Radial excision	Complete resolution
Hassankhani et al 72	2009	16	Female	L3	Spinous process	Asymptomatic	En bloc resection	N/A
Srikantha et al 73	2008	17	Male	C3	Spinolaminar junction	Symptomatic	En bloc resection	Complete resolution
	2008	23	Male	C4-C5	Transverse processes, lamina and pedicles	Symptomatic	Partial resection, C4-C5 corpectomy, C3-C5 fusion	Complete resolution
	2008	40	Female	C6	Superior articular facet	Symptomatic	Medial facetectomy	Complete resolution
Jo et al 74	2007	23	Male	L5-S1	Facet	Symptomatic	Partial laminectomy	Complete resolution
Zhao et al 76	2007	23	Female	C7	Transverse process	Symptomatic	En bloc resection	Complete resolution
Chatzidakis et al 77	2007	22	Male	C2	Dens of C2	Symptomatic	N/A	N/A
Ozturk et al 78	2007	46	Male	C1	Lamina	Symptomatic	Hemilaminectomy	Complete resolution
Song et al 75	2006	11	Male	T4	Superior articular process	Symptomatic	Laminectomy (T2-T3)	Complete resolution
Maheshwari et al 79	2006	20	Male	C7	Pedicle	Symptomatic	Laminectomy	Complete resolution
Moon et al 80	2006	16	Male	C5-C7	Spinous process	Symptomatic	Hemilaminectomy, complete excision of tumor	Complete resolution
Samartzis et al 81	2006	11	Male	S2	Lamina	Symptomatic	Laminectomy (S1-S4)	Complete resolution
McCall et al 82	2006	13	Female	C3	Lamina	Asymptomatic	Complete excision	N/A
Yoshida et al 83	2006	61	Female	C1	C1 anterior arch	Symptomatic	Complete excision	Complete resolution
Grivas et al 84	2005	46	Female	C7	Pedicle	Symptomatic	Complete excision	Complete resolution
Brastianos et al 85	2005	26	Female	T12	Vertebral body	Symptomatic	complete excision, T12 corpectomy	Complete resolution
Agrawal et al 86	2005	14	Male	L5-S1	Iliac crest	Symptomatic	Laminectomy	Complete resolution
Faik et al 87	2005	19	Male	T4-T5	Costovertebral angle, T4-T5 foramina	Symptomatic	Laminectomy, complete excision	Complete resolution
Miyamoto et al 88	2005	23	Male	C2	Pedicle	Symptomatic	Hemilaminectomy, partial excision	Partial functional recovery
Gille et al 93	2005	18	Female	C4	Transverse process	Symptomatic	Cervicotomy	Complete resolution
	2005	15	Male	C5	Vertebral body	Symptomatic	Laminectomy and cervicotomy	Complete resolution
	2005	73	Male	C2	Posterior arch	Symptomatic	Laminectomy	Complete resolution
	2005	18	Male	T11	Pedicle	Asymptomatic	Laminectomy	Complete resolution
	2005	28	Female	L4	Posterior arch	Symptomatic	Laminectomy	Complete resolution
	2005	45	Female	S1	Vertebral body	Symptomatic	Lumbotomy	Complete resolution
Kouwenhoven et al 89	2004	42	Male	C1-C2	Neural arches	Symptomatic	Laminectomy, en bloc resection	Complete resolution
Gurkanlar et al 90	2004	35	Male	L4	Lamina	Symptomatic	Complete excision	Complete resolution
Schrot et al 91	2004	15	Male	C7-T1	Posterior elements	Symptomatic	Hemilaminectomy and pediculectomy; complete excision	Complete resolution
Kulkarni et al 92	2004	15	Male	T10-T11	Facet	Symptomatic	Laminectomy	Complete resolution

Many studies have been published since the first case of solitary osteochondroma was reported by Reid in 1843, with an increase seen in recent years. Two literature reviews on spinal osteochondroma have been published: included 96 cases (1843–1992) and 54 cases (1992–2003). In present study, 168 new cases were updated from 2004 to 2020.

Osteochondromas are derived from the anterior cartilage and connective tissue. Most researchers believe that osteochondromas are hamartomas that occur in the metaphysis of long bones. Osteochondromas are divided into single and multiple forms. The latter is often referred to as osteochondromatosis or multiple exophytic chondroma, among other terms, and most of which are inherited in an autosomal dominant manner. Spinal osteochondromas are relatively rare, with an incidence rate of 1%–4%.[9,12,16] Among these, those with neurological symptoms account for .5%–1%.[19,20] Of spinal osteochondromas, nearly half of the patients occur in the cervical spine (C2>C3>C6).[8,13,19] The second most common occurrence of spinal osteochondromas is thoracic lesions.[14,17] Osteochondroma can occur during development due to abnormal development of the epiphyseal plate or frequent minor trauma. The high incidence of cervical osteochondroma is related to its high mobility and greater susceptibility to microtrauma of the epiphyseal plate of the vertebral body. In addition, secondary ossification centers with rapid growth and development have a greater chance of cartilage malformation, and thus of osteochondroma. The secondary ossification centers of the cervical spine ossify in adolescence, faster than the thoracic spine, and the lumbar spine ossifies the latest. Although the mobility of the lumbar spine is greater than that of the thoracic spine, but the ossification is later, so the incidence is lower. Spinal osteochondromas tend to occur in the appendages of the vertebral body, especially in the parts directly attached to the nerves or spinal cord. This tendency may be related to the appearance of secondary ossification centers of the spine during adolescence.

The etiology of osteochondromas is still unclear, and it may be related to the loss of the autosomal dominant tumor suppressor gene EXT-1 or EXT-2, excessive growth of cartilage tissue in the secondary ossification center, minor trauma, or X-ray irradiation.[51,58] Several papers reported that bone hyperplasia is also related to the pathogenesis of osteochondromas.[61,65] Furthermore, bone transformation may trigger out-of-control cell differentiation, leading to the occurrence of osteomalacia.[69,76]

In most patients, the cartilage cap and subcapsular fluid on the surface of the tumor are caused by excessive activity, trauma, strain, and other factors, and the tissues surrounding the tumor are edematous, causing compression symptoms.[81,84] Spinal osteochondromas can have a variety of clinical manifestations depending on the tumor location, growth rate, and degree of compression. The most common symptoms of spinal osteochondromas are radiating pain, dyskinesias, sensory disturbances, and urinary incontinence. Patients’ subjective symptoms generally gradually worsen but rarely cause acute attacks.

Diagnosis is mainly based on the selection of appropriate imaging examinations based on the patient’s symptoms. Due to the complex anatomical structure of the location of the spinal osteochondroma and the overlap, the diagnosis rate of routine X-ray is low and is thus only used as a screening reference. CT and MRI examinations, on the other hand, are pivotal in determining the nature of the disease, the location and extent of tumoral invasion of the spinal canal, and compression of the spinal cord and nerve roots. Typical osteochondroma lesions are shown on CT as cortical and cancellous bones connected to normal bone at the base. On CT, osteochondromas appear as expansive cauliflower-like bony masses with clear and irregular borders, visible cartilage caps, formation of internal calcification foci, and uneven bone crests and separation shadows. MRI may show different signal characteristics because the size of the lesion and the degree of cartilage calcification are related to signal intensity.[49,86] The cartilage cap exhibits different signals depending on the degree of calcification. If the cartilage cap is highly calcified, it will show a low signal on T1- and T2-weighted imaging. Conversely, if the cartilage cap is less calcified, it will show a high signal on T2WI or STIR image and a low to medium signal on T1WI. Thus, MRI is suitable for assessing the impact of tumors on surrounding tissues, such as the spinal cord and nerves. After enhancement, the fibrovascular tissues around, and between the cartilage will be strengthened. MRI can be considered the most accurate method for measuring cartilage cap thickness.

Although osteochondromas of the spine are benign tumors, they have a specific site of growth. The authors concluded that small, single osteochondromas growing outside the spinal canal are unnecessary to remove in the absence of clinical symptoms. However, larger osteochondromas or any osteochondroma that affects the spinal canal should be treated surgically to avoid causing or worsening spinal cord and nerve damage, especially when complete resection is complicated and difficult due to tumor enlargement. The tumor should be removed as much as possible during surgery because incomplete removal of the tumor body or cartilage cap can lead to tumor recurrence. The recurrence rate after resection is low, and the histological manifestations of recurring tumors are benign cartilage lesions and low-grade chondrosarcomas.[10,34] However, considering that not all studies clearly report this parameter, many recurrences may not be reported.

The most serious complication of osteochondromas is malignant transformation. The typical malignant transformation usually occurs after bone maturation and rarely occurs before the age of 20. The prognosis of spinal osteochondromas is generally good and is related to the degree and location of preoperative nerve damage. A better understanding of tumor biology and the development of advanced imaging and surgical techniques have made the treatment in recent years more convenient and effective.

Conclusion

Surgical treatment of a rare, lumbar osteochondroma has achieved good clinical results through posterior decompression and fusion surgery to alleviate radiating pain with paresthesia. Our literature review found that spinal osteochondromas mostly occurred on the cervical spine and often involved the posterior spine column. Solitary spinal lesions have caused neurologic symptoms, such as radiculopathy and myelopathy. The ideal treatment in almost all symptomatic cases is marginal excision of the tumor. Complete resection of the tumor cartilaginous cap is especially important to prevent recurrence and negative clinical outcomes.