Detection of numerical abnormalities at the 19p13.3 locus.

The SMARCA4 gene is located at 19p13.2, adjacent to 19p13.3, and this probe can also be used for the auxiliary diagnosis of SMARCA4-deleted thoracic sarcoma (SMARCA4-DTS). This tumor exhibits aggressive behavior, with immunohistochemical features including co-deletion of SMARCA4 and SMARCA2 and overexpression of SOX2. It primarily affects males (9:1), is often associated with smoking, and typically presents as a large mass in the mediastinum, pleura, or lung. In 2019, the American Journal of Surgical Pathology reported 30 cases of this tumor, emphasizing its disease classification and differential diagnosis.

Additionally, in 2018, Modern Pathology reported a series of 16 cases of SMARCA4-deleted undifferentiated uterine sarcoma, which exhibited striated muscle and small cell features and were associated with germline mutations.