Background: SWI/SNF-related, matrix-associated, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member (SMARCA4)-deficient thoracic sarcoma (SMARCA4-DTS) is a rare disease that has recently been described as an entity. It is characterized by an aggressive clinical course and specific genetic alterations. As an immunohistological feature, the tumors are deficient in SMARCA4 and SMARCA2 and express the sex-determining region Y-box 2 (SOX2). In contrast, Carney’s triad is a syndrome that combines three rare soft tissue tumors: gastric leiomyosarcoma, pulmonary chondroma, and extra-adrenal paraganglioma, of which at least two are required for diagnosis. Both diseases are valuable case, and there have been no previous reports of their coexistence.
Case presentation: A 43-year-old man visited our hospital because of respiratory distress. Computed tomography revealed a large mass measuring 55 mm in the upper lobe of his right lung and front mediastinum, with metastases in the surrounding lymph nodes. Needle biopsy was performed for diagnosis, and histological examination of the samples revealed monotonous epithelioid-like cells with loose binding and sheet-form proliferation. The tumor cells had distinct nuclei, with rhabdoid-kile cells in some locations. Immunohistochemical analysis revealed that the tumor cells were positive for SOX2, CD34, and p53 and negative for SMARCA4 and SMARCA2. The patient died 6 months after admission without any treatment. Autopsy revealed ganglioneuroma and enchondroma, suggesting an incomplete Carney complex.
Conclusion: SMARCA4-DTS is a rare and recently established disease. While it is difficult to siagnose, it is necessary to distinguish undifferentiated carcinoma, large cell carcinoma, Ewing sarcoma, epithelioid sarcoma, etc. when diagnosing tumors involving the mediastinum, In addition, case with both an incomplete Carney complex and SMARCA4-DTS are very rare. We discuss and report about SMARCA4-DTS by examining the expression of AT-rich interactive domain-containing protein 1A and solute carrier family 7 member 11.