Infantile Epithelioid Sarcoma with Genomic Segmental Amplification of BIRC3/YAP1 as Double Minutes Plus Trisomy 2: A Case Report

Beyond SMARCB1 Loss: Recent Insights into the Pathobiology of Epithelioid Sarcoma

Epithelioid sarcoma (ES) is a very rare and aggressive mesenchymal tumor of unclear origin and uncertain lineage characterized by a prevalent epithelioid morphology. The only recurrent genetic alteration reported in ES as yet is the functional inactivation of SMARCB1 (SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1), a key component of the SWI/SNF (SWItch/Sucrose Non-Fermentable) chromatin remodeling complexes. How SMARCB1 deficiency dictates the clinicopathological characteristics of ES and what other molecular defects concur to its malignant progression is still poorly understood. This review summarizes the recent findings about ES pathobiology, including defects in chromatin remodeling and other signaling pathways and their role as therapeutic vulnerabilities.

Malignant primitive epithelioid sarcoma with features of rhabdoid tumor presenting in utero with diffusely metastatic disease

Diagnosis of a tumor in utero is a rare occurrence and poses diagnostic and therapeutic challenges. In cases of tumor-associated hydrops, there is significant risk of fetal demise, and prenatal intervention may be considered to avoid this outcome when possible. When fetal intervention is unlikely to improve survival, information can be useful for counseling families. We present a rare case of fetal diagnosis of a primary renal malignancy with widespread metastases and hydrops, with unique immunohistochemical findings consistent with malignant primitive epithelioid sarcoma with features of rhabdoid tumor.