Rekhi Bharat, Kosemehmetoglu Kemal, Rane Swapnil, Soylemezoglu Figen, Bulut Elif
1 Tata Memorial Hospital, Mumbai, India.
2 Hacettepe University, Ankara, Turkey.
Int J Surg Pathol. 2018 Oct;26(7):637-643. doi: 10.1177/1066896918768043. Epub 2018 Apr 6.
Poorly differentiated chordomas are rare musculoskeletal tumors. Case 1. A 42-year-old lady presented with quadriparesis of 2 months' duration. Radiologic imaging disclosed a soft tissue mass in her left prevertebral- and paravertebral cervical region. Case 2. A 4-year-old male child presented with neck pain and restricted head movements of 1-year duration. Radiologic imaging revealed a contrast enhancing, paraspinal soft tissue mass in his cervical region. Microscopic examination in both the cases revealed a cellular malignant tumor composed of moderate to markedly pleomorphic cells with interspersed mitotic figures, along with focal myxoid change and necrosis. By immunohistochemistry, tumor cells in both cases were diffusely positive for pan cytokeratin (AE1/AE3) and brachyury, whereas these were negative for INI1/SMARCB1. Tumor cells in the second case were also positive for glypican3. The first case developed pulmonary metastasis, while the second case developed recurrence. Poorly differentiated chordomas are uncommon tumors, invariably characterized by loss of INI1. These tumors can be rarely seen in adults and need to be differentiated from their diagnostic mimics, in view of treatment implications and their relatively aggressive clinical outcomes.
低分化脊索瘤是罕见的肌肉骨骼肿瘤。病例1。一名42岁女性，出现持续2个月的四肢瘫痪。影像学检查显示其左颈前和椎旁区域有一软组织肿块。病例2。一名4岁男童，出现持续1年的颈部疼痛和头部活动受限。影像学检查显示其颈部有一强化的椎旁软组织肿块。两例的显微镜检查均显示为细胞性恶性肿瘤，由中度至明显多形性细胞组成，有散在的有丝分裂象，伴有局灶性黏液样改变和坏死。免疫组化显示，两例肿瘤细胞均弥漫性表达泛细胞角蛋白（AE1/AE3）和brachyury，而INI1/SMARCB1为阴性。第二例肿瘤细胞glypican3也呈阳性。第一例发生肺转移，第二例复发。低分化脊索瘤是罕见肿瘤，其特征总是INI1缺失。鉴于治疗意义和相对侵袭性的临床结局，这些肿瘤在成人中很少见，需要与诊断上的相似病变相鉴别。
