Advanced Unilateral Fibrous Dysplasia of the Scapula: A Rare Clinical Entity and Surgical Challenge

Abstract

Introduction: Fibrous dysplasia (FD) is an uncommon benign tumor of bone. Although FD can affect flat bones, it is rare for the scapula to be involved. In addition, little is known about the management of FD when it involves the scapula. We present possibly the first comprehensive case report of the management of advanced unilateral FD of the scapular region.

Case report: A 47-year-old male presented to us with pain and swelling over the left shoulder. The swelling was 11 cm × 15 cm × 8 cm and was hard and tender with rough texture. Radiograph showed large homogenous lesion with irregular but well-defined margins and a ground glass appearance. Magnetic resonance imaging scans showed well-defined borders with the expansion of the bone, with intact overlying cortices and endosteal scalloping. Biopsy confirmed the lesion to be FD. An innovative application of an existing surgical technique to minimize the impact of the residual deformity and dead space left after curettage of the scapula was done. The patient had good clinical and functional outcome at 6-month follow-up.

Conclusion: Surgical exercise in FD is purely on symptomatic basis. In our case, the swelling was causing most discomfort, and we curettaged and compressed the bony swelling which resulted in excellent outcome in this patient.

Keywords: Fibrous dysplasia; functional outcome; rare scapula lesion; unilateral fibrous dysplasia; unique surgical technique.

Figure 1

Anteroposterior radiograph of the left shoulder showing irregular expansile sclerotic lesions (red arrow) with overlying ground glass haziness (black arrow), involving the scapula, sparing its superior, and medial borders. Features suggest fibrous dysplasia, but chondrosarcoma should be included in the differential diagnosis.

Figure 2

Coronal T1-weighted magnetic resonance imaging of the left shoulder showing the expansile scapular lesion (red thick arrow), with high signal intensity surrounded by scalloped low signal intensity rim (yellow thin arrow). The pattern suggests a proteinaceous or hemorrhagic content.

Figure 3

Short TI Inversion Recovery (Fig. 3) axial magnetic resonance imaging demonstrating a lesion with high signal intensity (red arrow) surrounded by scalloped margins (white arrow).

Figure 4

Intermediate-power view of typical histology of fibrous dysplasia. Note the bland fibrous stromal tissue (white arrow) with islands of disorganized, immature osteoid (red arrow). A key feature is the absence of rimming osteoblasts around the osteoid.

Figure 5

Shows pre-operative landmarks of approach and skin incision (red arrow).

Figure 6

(a) Post-operative sagittal computed tomography (CT) scan of the left scapula shows mildly expansile lytic lesion with irregular border (thin arrow). (b) Post-operative coronal CT scan of the left scapula shows some septation of the scapula body with a hazy bone matrix (thick arrow). (c) Post-operative axial CT scan of left scapula shows thinned expansion and deformity of the scapula with surgical defects in the cortex. The dead space has been considerably reduced (red arrow).