Solitary osteochondroma of the scapula: a rare case report

Abstract

Introduction: Osteochondroma is the most common benign bone tumor representing about 15 % of all bone tumors and 45.3 % of the benign bone tumors. They commonly arise from the metaphysis of a long bone with most common sites being distal femur, proximal tibia or proximal humerus. The occurrence of osteochondroma in flat bones particularly the scapula is uncommon.
Case Presentation: In view of its rarity, we report a case of solitary osteochondroma of the scapula in an 18 year old male arising from the postero medial aspect of the body of scapula which was managed by excisional biopsy. He presented with a painless swelling of 2 years duration over the left scapula. Histopathology confirmed the diagnosis with no evidence of malignant transformation.
Discussion: Osteochondromas are primary bone tumors rarely found arising from the scapula. Although the exact etiology of the growth is unclear, it is due to a portion of physis herniating through the growth plate. Complications like malignant transformation, winging of scapula and restriction of shoulder movements can occur. Thickness of cartilagenous cap is an important predictor of malignant change.
Conclusion: Solitary osteochondroma of the scapula is a rare entity .Timely diagnosis and complete excision of the tumor should be done in order to avoid recurrence and prevent complications.

Full text

Copyright © 2014 Dr Amit Grover et al. This is an open access article distributed under the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
International Journal of Medicine, 2 (xx) (2014) xxx-xxx
International Journal of Medicine
Journal home page: www.sciencepubco.com/index.php/IJM
doi:
Research Paper
Solitary osteochondroma of the scapula: a rare case report
Rahul P 1, Ravikumar Tv 1, Amit Grover 2*, Sudarshan K 2
1MS ORTHO, Assistant Professor, Department of Orthopaedics, MS Ramaiah Medical College, Bangalore
2Postgraduate in Orthopaedics, MS Ramaiah Medical College, Bangalore
*Corresponding author E-mail: amitgrover88@gmail.com
Abstract
Introduction: Osteochondroma is the most common benign bone tumor representing about 15 % of all bone tumors and 45.3 % of the
benign bone tumors. They commonly arise from the metaphysis of a long bone with most common sites being distal femur, proximal
tibia or proximal humerus. The occurrence of osteochondroma in flat bones particularly the scapula is uncommon.
Case Presentation: In view of its rarity, we report a case of solitary osteochondroma of the scapula in an 18 year old male arising from
the postero medial aspect of the body of scapula which was managed by excisional biopsy. He presented with a painless swelling of 2
years duration over the left scapula. Histopathology confirmed the diagnosis with no evidence of malignant transformation.
Discussion: Osteochondromas are primary bone tumors rarely found arising from the scapula. Although the exact etiology of the growth
is unclear, it is due to a portion of physis herniating through the growth plate. Complications like malignant transformation, winging of
scapula and restriction of shoulder movements can occur. Thickness of cartilagenous cap is an important predictor of malignant change.
Conclusion: Solitary osteochondroma of the scapula is a rare entity .Timely diagnosis and complete excision of the tumor should be
done in order to avoid recurrence and prevent complications.
Keywords: Osteochondroma, Solitary, Scapula.
1. Introduction
Osteochondroma is a cartilaginous excresence considered to be the
most common benign bone tumour and amounting to 35-45% of
all neoplastic benign lesions of osseous structure (Tomo et
al.2005, Mohsen et al.2006). The true incidence is not known as
most of them are asymptomatic.
Osteochondroma are usually found in the metaphysis of a long
bone to the extent of 90 % with most common sites being distal
femur, proximal tibia or proximal humerus of young males
(K.Krishnan 2001). The incidence of osteochondroma in pelvis is
about 5 % and in scapula is 4% (Calafiore G et al.2001).
Asymptomatic painless slow growing mass is the usual presenta-
tion of an Osteochondroma. However it may become symptomatic
in case of associated complications like mass effect causing pres-
sure, fracture of bony stalk, impingement of nerves, malignant
transformation or bursitis (Mohsen et al.2006).
Scapular osteochondromas can present with pseudowinging of the
scapula, restricted movements, abnormal scapulothoracic motion
and crepitus with movement of the involved shoulder (Okada K et
al.1999, Essadki B et al.2000, Mohsen et al.2006)
We report a case of solitary osteochondroma of the scapula in an
18 year old male presenting with gradually increasing size arising
from the posteromedial aspect of the body of scapula which was
managed by excisional biopsy.
2. Case Presentation
An eighteen year old male presented to us with a chief complaint
of a painless swelling over the left scapular region since 2 years.
It was insidious in onset but the patient complained of a gradual
increase in the size of the swelling (Figure 1).There was no history
of trauma or swelling elsewhere in the body. Family history was
insignificant.
Fig. 1: Clinical Picture on Presentation Showing the Swelling over the
Left Scapula
On examination the swelling was bony hard in consistency, meas-
uring about 4*3 cm with a smooth surface arising from the left
scapula. Swelling was immobile, non-tender and skin overlying
the swelling was normal. There was no localized tenderness or
signs of inflammation. Movement at the shoulder joint was re-
stricted only terminally. Neurological status was normal.
Routine blood investigations, ESR, CRP and alkaline phosphatase
were within normal limits. Plain radiograph revealed a growth
over the postero medial aspect of the left scapula suggestive of a
solitary osteochondroma (Figure 2). MRI confirmed the diagnosis
and showed a pedunculated lesion arising from the posteromedial
aspect of the body of scapula just above the spine measuring 15
*21 mm. Cartilage cap was 2.5 mm in thickness. There was no
evidence of bursitis (Figure 3).There was no evidence of any soft
tissue mass.

2
International Journal of Medicine
Fig. 2: Xray of Shoulder Showing a Solitary Osteochondroma of the Left
Scapula
Fig. 3: MRI of Shoulder Showing a Solitary Osteochondroma of the Left
Scapula
A decision was taken to do an excisional biopsy of the swelling as
the patient complained that it was increasing in size and was un-
sightly.
Under general anaesthesia, patient was put in a prone position and
an incision was made over the swelling. The entire tumor was
excised and sent for histopathology (Figure 4). Histopathology
results correlated with the diagnosis of a solitary osteochondroma.
Section showed a lesion composed of many mature bony trabecu-
lae located beneath a cartilagenous cap with no evidence of malig-
nant changes (Figure 5). Post-operative period was uneventful. At
8 months of follow up patient has full range of motion of the
shoulder with no evidence of recurrence.
Fig. 4: Intraoperative Picture of the Osteochondroma
Fig. 5: Histopathology Section
3.Discussion
Osteochondromas is considered to be the most common benign
bone tumour accounting for 35-45% of all neoplastic benign le-
sions of osseous structure (Tomo et al.2005, Mohsen et al.2006).
Although the exact etiology of the growth is unclear, it is due to a
portion of physis herniating through the growth plate. The meta-
plastic cartilage grows and forms exostosis which is connected
with a thin stalk having a marrow cavity in continuity with the
underlying bone (Essadki B et al.2000).Commonly found in
young individuals usually in the second decade of life. They are
most commonly found in the long bones and the flat bones like the
pelvis and the scapula account for 4-6% cases.
Osteochondromas are usually asymptomatic. They may present as
a painless swelling. Symptoms can be secondary to complications
like mechanical pressure due to mass effect, restriction of shoulder
movements, bony stalk fractures, impingement of the nerves, and
formation of large bursa. Scapular osteochondroma can present
with a winging of scapula with neurologically intact serratus ante-
rior muscle (Mohsen et al.2006).
Malignant transformation of the cartilaginous cap to a chondrosar-
coma occurs in 1 % cases of solitary osteochondroma (Mohsen et
al.2006). It presents with sudden increase in size with pain. Thick-
ness of cartilagenous cap is an important predictor of malignant
change. A cap thicker than 2 cm indicates malignant transforma-
tion (Malghem J et al.1992).
These are usually treated by surgical excision or arthroscopic re-
section (Reit RP et al.2007).Incomplete resection can lead to re-
currence. Clean surgical margins help to prevent recurrences
(Pérez D et al.2011)
We planned for an excision of the osteochondroma because of an
increase in the size of the mass and since it causing terminal re-
striction of motion.
4. Conclusion
Solitary osteochondroma of the scapula is a rare entity. It can lead
to winging of scapula, restriction of shoulder movement, abnormal
scapulothoracic motion or malignant transformation. Complete
excision of the tumor should be done in order to avoid recurrence
and prevent complications
Conflict of Interests
The authors hereby declare that they have no conflict of interests
to declare.
Ethical approval
Ethical consent for the work has been given.
Consent
The authors confirm that the patient described in this paper has
given his informed consent for the paper to be published.

International Journal of Medicine
3
References
[1] Tomo H, Ito Y, Aono M, Takoaka K. Chest wall deformity associated
with osteochondroma of the scapula: a case report and review of the
literature. J Shoulder Elbow Surg 2005; 14:103–6
http://dx.doi.org/10.1016/j.jse.2004.03.007.
[2] Mohsen MS, Moosa NK, Kumar P. Osteochondroma of the scapula
associated with winging and large bursa formation. Med Princ Pract
2006; 15:387–90. http://dx.doi.org/10.1159/000094275.
[3] K.Krishnan Unni. Cartilaginous lesions of bone. Journal of Orthopae-
dic Science.2001; 6 (5):457-472
http://dx.doi.org/10.1007/s007760170015.
[4] Calafiore G, Calafiore G, Bertone C, Urgelli S, and Rivera F,
Maniscalco P: Osteochondroma: report of a case with atypical locali-
zation and symptomatology. Acta Biomed Ateneo Parmense 2001; 72:
91–96.
[5] Okada K, Terada K, Sashi R, Hoshi N. Large bursa formation associ-
ated with Osteochondroma of the scapula: a case report and review of
the literature. Jpn J Clin Oncol. 1999; 29(7):356-60.
http://dx.doi.org/10.1093/jjco/29.7.356.
[6] Essadki B, Moujtahid M, Lamine A, Fikry T, Essadki O, Zryouil B:
Solitary osteochondroma of the limbs: clinical review of 76 cases and
pathogenic hypothesis. Acta Orthop Belg 2000; 66: 146–153.
[7] Malghem J, Berg BV, and Noel H, Maldague B: Benign
osteochondroma and exostosis chondrosarcomas: evaluation of carti-
lage cap thickness by ultrasound. Skel Radiol 1992; 21: 33–37
http://dx.doi.org/10.1007/BF00243091.
[8] Reit RP, Glabbeek FV. Arthroscopic resection of a symptomatic
snapping subscapular osteochondroma. Acta Orthop Belg. 2007;
73:252-54.
[9] Pérez D, Ramón Cano J, Caballero J, López L: Minimally-invasive
resection of a scapular osteochondroma. Interact Cardiovasc Thorac
Surg 2011, 13(5):468–470.
http://dx.doi.org/10.1510/icvts.2011.274621.