|Ahead of print publication
Rib osteochondroma presenting as acute paraparesis
Puneeth Kumar1, Padma Badhe1, Amit Kumar Dey2
1 Department of Radiology, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India
2 Department of Radiology, Seth GS Medical College and KEM Hospital, Mumbai, Maharashtra, India; Department of Cardiology, National Institutes of Health, Bethesda, Maryland, USA
|Date of Submission||05-Apr-2020|
|Date of Decision||16-Jul-2020|
|Date of Acceptance||02-Oct-2020|
|Date of Web Publication||03-Nov-2021|
Amit Kumar Dey,
MD; NHLBI, NIH, Bethesda-Maryland-20814
Source of Support: None, Conflict of Interest: None
Osteochondromas are usually osseous outgrowths arising from the metaphyseal region of cortical bone. Moreover, osteochondroma can also arise from flat bones and the spine. However, their origin in the ribs is extremely rare and always near the costochondral junction. We present a 26-year-old male who presented with chief complaints of difficulty in walking for 2 weeks subsequently diagnosed with osteochondroma based on the presence of a cartilage cap on Magnetic resonance imaging.
Keywords: Computed tomography, imaging, magnetic resonance imaging, osteochondroma
| > Introduction|| |
Osteochondromas are usually osseous outgrowths arising from the metaphyseal region of cortical bone. Moreover, osteochondroma can also arise from flat bones and the spine. However, their origin in the ribs is extremely rare and always near the costochondral junction. Less than five cases are reported in the literature. We present the case of a young patient with exostoses displaying as mediastinal masses, which exerted pressure on the neural pathway and network, leading to downstream effects.
| > Case Report|| |
A 26-year-old male presented with chief complaints of difficulty in walking for 2 weeks. The patient also complained of tingling and numbness, affecting both legs a week ago. On examination, power in the lower extremities was weak graded as 2–3 along with significant analgesia. There was no medical history of neurologic dysfunction or bony tumor. Chest X-ray was surprising and showed a dense lobulated bone lesion related to the 5th rib on the right side. Axial computed tomography (CT) revealed solid expansile iso-hyperintense lesion from the posterior part of the 5th rib on the right side [Figure 1]a. Axial magnetic resonance imaging (MRI) (T2 window) also revealed solid expansile iso-hyperintense lesion from the posterior part of 5th rib on the right side along with a cartilaginous cap [Figure 1]b. The diagnosis of osteochondroma was made based on the presence of a cartilage cap on MRI and subsequent H and E image [Figure 1]c. Therefore, en bloc surgery was performed, after which lower extremity weakness and numbness improved. One week after surgery, CT scans showed an enlarged spinal cord and complete resection of the osseous mass. At the 6-month follow-up examination, the weakness had completely resolved. An additional CT scan obtained at 1 year after surgery did not show any evidence of recurrence of the tumor.
|Figure 1: (a) Axial computed tomography images reveal solid expansile iso-hyperintense lesion seen to be arising from the posterior part of the 5th rib on the right side which shows spinal canal extension with compression of dorsal spinal cord to the left. (b) Axial magnetic resonance imaging image of magnetic resonance imaging scan (T2 window) reveal solid expansile iso-hyperintense lesion with hyperintense cartilage cap seen to be arising from the posterior part of the 5th rib on the right side which shows spinal canal extension with compression of dorsal spinal cord to the left without any evidence of cord edema. (c) Pathological hematoxylin and eosin image depicting osteochondroma with cartilage cap|
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| > Discussion|| |
The tip of the osteochondroma is usually cartilaginous and thus has a 1% risk of malignant transformation into chondrosarcoma. MRI is the diagnosis of choice and also aids in recognizing malignant transformation. Conservative treatment is usually favored; however, a surgical strategy including decompression surgery such as laminectomy and/or facetectomy at the corresponding level for complete tumor excision needs to be carefully planned if necessary. Annual CT, along with further clinical and radiologic follow-up is required.,
This is an interesting case of a young patient presenting with nonspecific symptoms, with no family history of exostosis. Computed tomography imaging revealed the exostoses, manifested as mediastinal masses, with protrusion into the thoracic cavity, exerting compressive effects on the neural network. MRI confirmed the diagnosis of osteochondroma based on the presence of a cartilage cap. However, the possibility of chondrosarcoma could not be excluded because of the age of the patient and the presence of somewhat bone erosion.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| > References|| |
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Aghajanzadeh M, Rimaz S, Hassanzadeh R, Mostafaie O, Ildari S. Costochondral exostoses mimicking as a posterior mediastinal mass: A case report. Ann Clin Cytol Pathol 2017;3:1069-72.
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