SATB2可用作骨母细胞分化的免疫组化标记物。由于皮肤肉瘤伴随病人皮肤、软组织和骨头同时累及或病史中有骨肉瘤的情况，所以有时会被误诊为骨肉瘤。在这些情况下，SATB2免疫组化的实用性尚不明确，我们旨在确定SATB2在各种皮肤肉瘤中的表达频率和模式。通过强度（0-3）和范围（0-100％）评估免疫组化的SATB2表达，为每个案例生成H分数。表达水平分为高阳性（H分数≥100），低阳性（20-99）和阴性（<20）三类。在所有检测到的肉瘤中，18/23（78％）非典型纤维瘤肉芽肿（AFX），10/19（53％）多形性皮肤肉瘤，9/20（45％）皮肤肉样鳞状细胞癌，14/39（36％）皮肤肉毒黑素瘤，2/13（15％）质差的皮肤血管肉瘤，10/17（59％）高级别皮肤平滑肌肉瘤和7/8（88％）骨肉瘤对照组均观察到阳性的SATB2表达。除AFX外，所有皮肤肉瘤的平均H分数均明显低于骨肉瘤。在所有检查的皮肤肉瘤中，AFX的平均H分数为71，高阳性病例的百分比为48％。所有皮肤病例中只有两个（1.5％）显示出强烈的染色强度。各种皮肤肉瘤中普遍存在的SATB2表达可能会在鉴别诊断包括骨肉瘤的情况下产生潜在的诊断误区。强染色和高阳性H分数的要求可以提高SATB2鉴别这些肿瘤与骨肉瘤的特异性。版权所有©2023 Australasia皇家病理学院。由Elsevier B.V.出版。保留所有权利。

SATB2 can be used as an immunohistochemical marker for osteoblastic differentiation. The differential diagnosis of a cutaneous sarcomatoid neoplasm sometimes includes osteosarcoma when the tumour concomitantly involves the skin, soft tissue, and bone, or when there is a past medical history of osteosarcoma. As the utility of SATB2 immunohistochemistry in these scenarios was unclear, we aimed to determine the frequency and the pattern of SATB2 expression in a variety of cutaneous sarcomatoid neoplasms. SATB2 expression by immunohistochemistry was evaluated by intensity (0-3) and extent (0-100%) of staining to generate an h-score for each case. Expression levels were classified into high-positive (h-score ≥100), low-positive (20-99), and negative (<20) groups. Positive SATB2 expression was observed in 18/23 (78%) atypical fibroxanthomas (AFX), 10/19 (53%) pleomorphic dermal sarcomas, 9/20 (45%) cutaneous sarcomatoid squamous cell carcinomas, 14/39 (36%) sarcomatoid melanomas, 2/13 (15%) poorly differentiated cutaneous angiosarcomas, 10/17 (59%) high-grade cutaneous leiomyosarcomas, and 7/8 (88%) osteosarcoma controls. With the exception of AFX, all cutaneous neoplasms showed significantly lower average h-scores than osteosarcoma. AFX gave the highest average h-score (71) and percentage of high-positive cases (48%) among all examined cutaneous neoplasms. Only two (1.5%) of all cutaneous cases showed strong intensity of staining. Common SATB2 expression in various cutaneous sarcomatoid neoplasms poses a potential diagnostic pitfall when the differential diagnosis includes osteosarcoma. Requirement of strong staining and a high-positive h-score improves the specificity of SATB2 in differentiating these tumours from osteosarcoma.Copyright © 2023 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.