PMC5460384_01
(a) Clinical photograph before the surgery shows a dotted circle at the left shoulder that indicates the area at which the patient complained of pain. The area includes the supra- and infraspinatus muscles and the suprascapular nerve. (b) Radiograph of the left shoulder shows a radiolucent cystic lesion in the superior glenoid.
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The area at which he experienced spontaneous shoulder pain was innervated by the suprascapular nerve (Figure 1(a)). Plain anteroposterior radiography of the left shoulder showed a circular lesion with marginal osteosclerosis at the glenoid (Figure 1(b)).
(a) Magnetic resonance (MR) T2-weighted axial image of the left shoulder shows a high intensity area at the glenoid. (b) MR T2-weighted sagittal image of the left shoulder shows that the intraosseous lesion is linked to the spinoglenoid notch. (c, d) Computed tomography (CT) axial and 3-dimensional CT images of the left shoulder show a bone cystic lesion of the glenoid with cortical bone destruction linked to the spinoglenoid notch.
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Magnetic resonance imaging (MRI) showed an osteolytic cystic lesion with very high intensity on T2-weighted images and low intensity on T1-weighted images, and the lesion was located at the posterior cranial portion of the glenoid and partially extended to the spinoglenoid notch (Figures 2(a) and 2(b)), and there were no findings about fatty change and intramuscular edema in supra- and infraspinatus muscles. Computed tomography (CT) showed a circular cystic lesion with marginal osteosclerosis and cortical bone destruction of the posterior glenoid at the spinoglenoid notch (Figures 2(c) and 2(d)).
(a) Surgery for the intraosseous ganglion is performed in the right lateral position. A 10 cm skin incision is made at the posterior glenohumeral joint. (b) Intraoperative photograph of the posterior shoulder shows the suprascapular nerve after splitting the infraspinatus (yellow arrow). (c) Intraoperative photograph shows a mucinous cyst wall after shifting the suprascapular nerve laterally. (d) Intraoperative photograph shows the bone cavity of the glenoid after curettage of the cyst (yellow arrowheads).
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Curettage was performed under general anesthesia in the right lateral position (Figure 3(a)). The spinoglenoid notch was directly visualized after splitting the teres minor and infraspinatus muscles, and the suprascapular nerve and cyst were identified at the spinoglenoid notch (Figure 3(b)). After releasing the nerve gently from the cyst (Figure 3(c)), an incision was made at the cyst wall, and gelatinous material flowed out from the cyst. The suprascapular nerve was retracted gently, and curettage was performed until the bone surrounding the cyst was completely exposed (Figure 3(d)).
(a, b) Microscopic section of the cyst wall shows that the wall contained connective tissue, including collagen fibers and a few fibroblasts, and that the inner layer of connective tissue had myxoid change. The yellow arrow indicates the myxoid area, and the yellow arrowheads show connective tissue, including collagen fibers and a few fibroblasts (hematoxylin and eosin staining; A: x12.5 magnification, B: x50 magnification).
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Histological examination revealed that the cyst wall contained connective tissue, including collagen fibers and a few fibroblasts, and that the inner layer of connective tissue exhibited myxoid change (Figures 4(a) and 4(b)).