Notable Response of SMARCA4-Deficient Undifferentiated Uterine Sarcoma to Palliative Radiation Therapy

SMARCA4-Deficient Undifferentiated Tumor of the Esophagus: Diagnostic Pitfalls in Immunohistochemical Profiles

SMARCA4-deficient undifferentiated tumors (SMARCA4-UT) are a newly described entity and are typically seen in the thoracic cavity. However, these tumors have been described in other body sites, including the esophagus. These tumors are rare, aggressive neoplasms, characterized by the loss of protein product of SMARCA4 (Brahma-related gene-1) and the preservation of INI1 (SMARCB1) expression. Here, we present two tumors of SMARCA4-UT of the esophagus with its microscopic appearance and immunohistochemical profile. We also include a literature review of SMARCA4-deficient tumors of the tubular gastrointestinal tract with their immunohistochemical and mismatch repair profiles for each specimen. Due to its non-specific histologic appearance and variable staining in expanded immunohistochemical panels, this tumor frequently overlaps with other tumor types, making the diagnosis of SMARCA4-UT challenging. These tumors are often associated with intestinal metaplasia of the esophagus and are thought to represent a high-grade undifferentiated transformation of a conventional esophageal adenocarcinoma. These tumors are typically associated with poor clinical outcomes and have poor response to conventional therapies. Currently, there are no standard guidelines for treatment of these tumors; however, palliative radiotherapy and systemic chemotherapy may provide benefit. More recently, immunotherapy and novel therapeutic targets have shown some promise for these patients.

SMARCA4-deficient uterine tumors in young women: response to immune checkpoint inhibitors

SMARCA4-deficient tumors have been reported in various organs and are associated with a poor prognosis. SMARCA4-deficient undifferentiated uterine sarcoma (SDUS) was first described in 2018. Conversely, loss of SMARCA4 (BRG1) expression, as observed by immunostaining, has been observed in several cases of undifferentiated endometrial carcinoma. SDUS has considerable morphologic overlap with undifferentiated endometrial carcinoma, while there are differences in their clinicopathological features. Here, we present two cases of SMARCA4-deficient uterine tumors in patients in their 20 s: SDUS (Case 1) and undifferentiated endometrial carcinoma without SMARCA4 nuclear expression (Case 2). Using comprehensive genome profiling, we found that both cases had SMARCA4 mutations, with tumor mutation burdens of 0 and 68 Muts/Mb, respectively. Case 1 had multiple lung metastases 9 months after surgery. We treated the patients with combination of an immune checkpoint inhibitor (pembrolizumab) and a multikinase inhibitor (lenvatinib), and the response to the treatment was stable. This study presents the first report on the response to immune checkpoint inhibitor and multikinase inhibitor in SDUS.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13691-024-00721-2.

SMARCA4‑deficient uterine adnexal tumor with ascites: A case report and literature review

SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily A member 4 (SMARCA4)-deficient tumors are rare and highly aggressive tumors characterized by a loss of SMARCA4 expression, and SMARCA4-deficient tumors in the adnexal area of the uterus are particularly rare. The present study describes the case of a 64-year-old woman who was admitted to Weifang People's Hospital (Weifang, China) with abdominal distension, and was observed to have a mass with ascites in the adnexal area of the uterus. Based on clinical, imaging and pathological findings, the patient was diagnosed with a SMARCA4-deficient adnexal tumor with ascites. Biopsy of the left and right adnexal lesions was performed, and the patient was administered chemotherapy. After one cycle of bevacizumab, sindilizumab and carboplatin, no further treatment was administered. After biopsy and chemotherapy, the abdominal distension was alleviated and the general condition of the patient was satisfactory. The patient was followed up and died 3 months after treatment. Notably, it is important to avoid misdiagnosing this tumor as other types of adnexal uterine tumors, and morphological and immunohistochemical features may be useful for diagnosing primary SMARCA4-deficient tumors in the adnexal area of the uterus.