PMC8497169_01
(a) Conventional radiograph of the right shoulder showing a lytic lesion involving the right scapula near the glenoid. (b) Computed tomography depicting the osteolytic lesion at the scapula with associated cortical destruction and extension into the surrounding soft tissue.
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Radiography of his right shoulder revealed a lytic lesion adjacent to the glenoid cavity (Figure 1(a)). CT revealed an osteolytic lesion destroying the cortical bone, and partial sclerosis was observed in part of the periphery of the tumor (Figure 1(b)).
Magnetic resonance imaging at first presentation (a)-(c), and postchemotherapy (d). The lobulated tumor is located at the scapula and is seen invading into the anterior and posterior soft tissue. (a) Axial T1-weighted image shows slightly high signal intensity. (b) Axial T2-weighted image depicts high signal intensity-multilocular mass with low signal intensity rim, and a part of the nodule shows fluid-fluid level (white arrowhead). (c) Axial Gd enhanced T1-weighted image represents thin enhancement surrounding low-intensity rim and enhanced solid nodule (arrow). Partial invasion into soft tissue is observed (asterisk). (d) Axial Gd enhanced T1-weighted image after chemotherapy shows cystic change of solid nodule compared with prechemotherapy image in (c) panel.
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Magnetic resonance imaging (MRI) showed a 4.5 x 3.5 cm mass penetrating into soft tissue as detected by CT (Figure 2). The size of the tumor did not change after chemotherapy, but cystic changes in the solid part of the tumor progressed (Figure 2(d)), and the accumulation of FDG at the axillary lymph node was diminished.
18F-FDG-PET/CT scan at first presentation. PET/CT fusion image shows increased FDG uptake in (a) the scapular tumor (SUV max 4.16) and (b) axillary lymph node (SUV max 2.8).
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Fluorodeoxyglucose positron emission tomography (FDG PET/CT) depicted uptake of FDG in the tumor with SUVmax of 4.16, and a small lymph node swelling with SUV max of 2.8, which was suspected to be metastasis from the tumor or a reactive lymph node swelling (Figure 3).
Hematoxylin and eosin staining of the tumor tissue. (a) Proliferation of spindle cells with high cellularity and atypical cells with bizarre nuclei are observed. (b) Tumor cells (white arrowhead) infiltrate the subchondral bone under the glenoid cartilage. (c) Tumor cells (white arrowhead) invading surrounding fibroadipose tissue, and (d) lymphoplasmacytic infiltration (white arrowhead) surrounding fibrous capsule (black arrow).
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Histopathological examination of the CT-guided needle biopsy resulted in a diagnosis of spindle cell sarcoma (Figure 4). Microscopically, spindle cells with high cellularity and partially atypical cells with bizarre nuclei were observed (Figure 4). Focal invasion of the tumor cells into the surrounding bone and soft tissue was noted, and lymphoplasmacytic infiltration was observed around the fibrous capsule of the tumor (Figure 4).