Epithelioid Sarcoma Arising in a Long-Term Survivor of an Atypical Teratoid/Rhabdoid Tumor in a Patient With Rhabdoid Tumor Predisposition Syndrome

Abstract

Rhabdoid tumor predisposition syndrome (RTPS) is defined as the presence of a SMARCB1 or SMARCA4 genetic aberration in a patient with malignant rhabdoid tumor. Patients with RTPS are more likely to present with synchronous or metachronous rhabdoid tumors. Based on the current state of rhabdoid tumor taxonomy, these diagnoses are based largely on patient demographics, anatomic location of disease, and immunohistochemistry, despite their nearly identical histologic and immunohistochemical profiles. Thus, the true distinction between such tumors remains a diagnostic challenge. Central nervous system atypical teratoid/rhabdoid tumor (AT/RT) is a rare, aggressive, primarily pediatric malignancy with variable histologic features and a well documented association with loss of SMARCB1 expression. Epithelioid sarcoma (ES) is a rare soft tissue tumor arising in patients of all ages and characteristically staining for both mesenchymal and epithelial immunohistochemical markers while usually demonstrating loss of SMARCB1 expression. To our knowledge we herein present the first documented case of a patient with RTPS who presented with metachronous AT/RT and ES.

Atypical epithelioid cells in pleural effusion as foreign second population: A diagnostic cytopathology dilemma

“…In contrast to EHE, epithelioid sarcoma cells can express epithelial markers such as AE1/AE3 and epithelial membrane antigen (EMA), and the expression of INI1 is often absent. [ 21 - 24 ]…”

SWI/SNF Complex Alterations in Tumors with Rhabdoid Features: Novel Therapeutic Approaches and Opportunities for Adoptive Cell Therapy

“…Biallelic-inactivating SMARCB1 mutations are the most frequent aberration. Nonsense frameshift and splice site mutations complete the causes of SMARCB1 loss, but these are quite rare [ 62 , 63 , 64 ]. Preclinical data have suggested that some miRNAs (miR-193a-5p, miR-206, miR-381, miR-671-5p) are involved in SMARCB1 inactivation through epigenetic mechanisms [ 65 , 66 , 67 ].…”

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

“…A case of homozyogously deleted ES occurring in the setting of SMARCB1 constitutional deletion was reported by Le Loarer and coworkers in a 25-year-old ES patient without prior familial or personal history of cancer [ 57 ]. More recently, an ES arisen in a patient affected by a rhabdoid tumor predisposition syndrome due to a constitutional intron/exon SMARCB1 variant (c.501-1G > A), likely responsible for aberrant mRNA splicing, has been documented [ 60 ].…”