Solitary Sessile Osteochondroma of Scapula, A Rare Case Report

Abstract

A swelling was noticed over the right scapula of a four year old boy by his parents since the past one year, which showed progress since past 6 months [Table/ Fig-1]. On examination, no similar swe ll ing was seen, which arose from else where in the body. Family history was not significant. On examination, a 4x3cm bony swelling which arose from body of left scapula was noticed. The swelling was hard in consistency, it had a smooth surface and it was immobile, but it moved with scapula. Skin over the swelling was normal and there were no neurological deficits. Forward flexion, abduction and extension of shoulder joints were restricted terminally.Plain radiograph of right shoulder revealed a mushroom shaped, solitary osteochondroma. MRI showed a bony swelling of size, 30x17mm, which arose from the dorsal surface of the body of the scapula. The cartilage cap thickness was 5mm. The cortex and the medullary cavity were continuous with the scapula. There was no associated soft tissue mass or pathological fracture.He was taken up for excisional biopsy, as the swelling restricted his shoulder movements and was cosmetically not acceptable [Table /Fig-2]. Under general anaesthesia in prone position, an oblique incision was made and the entire tumour was excised. Histopathological examination concurred with our preoperative diagnosis. There was no evidence of malignant changes. Postoperative period was uneventful and the boy regained appreciable shoulder range of motion with physiotherapy. After six months of follow-up, there was no evidence of recurrence. Histopathological examination showed normal appearing chondrocytes which were covered by hyaline cartilage. There is no evidence of any malignant transformation [Table/ Fig-3]. Orthopaedics section aBstRaCtOsteochondromas are the most common benign tumours of bone. These are most commonly seen on the metaphysis of a long bone, but they can arise from any bone which is preformed from cartilage. To best of our knowledge, very few cases of osteochondroma scapula have been reported in literature. We hereby report a very rare case of osteochondroma which arose from scapula in a four year old boy, which was treated by excisional biopsy.[table/ Fig-1

Rare Case of Osteochondroma on the Dorsal Aspect of the Scapula

“…Our patient presented with a dorsal surface scapular osteochondroma which is an unusual location considering an incidence rate of 3-4.5% compared to the incidence in long bones. The location of scapular tumors is divided into two zones [11]. Overall, 14.4% of scapular tumors are osteochondromas, and the ventral surface is more commonly involved compared to the dorsal surface.…”

“…However, with larger tumors, it may be impossible to preserve the scapula by performing partial or complete scapulectomy. Though malignant transformation is rare in a solitary osteochondroma, multiple osteochondromas and sudden growth after the third decade of life must raise suspicion of its malignant transformation into osteosarcoma, which necessitates appropriate management [9,11]. This change is evidenced by the measurement of cartilage thickness of more than 2 cm on a CT scan or MRI.…”