Paired Primary and Recurrent Rhabdoid Meningiomas: Cytogenetic Alterations, BAP1 Gene Expression Profile and Patient...

Area of Science:

• Neuro-oncology
• Cancer genetics
• Pathology

Background:

• Rhabdoid meningiomas (RM) are a rare subtype of meningioma.
• RM exhibit a heterogeneous clinical course and a high recurrence rate, even after complete surgical resection.
• Understanding the genetic underpinnings of RM recurrence is crucial for improved patient management.

Purpose of the Study:

• To retrospectively analyze the clinical-histopathological and cytogenetic features of rhabdoid meningiomas.
• To identify genetic differences between recurrent and non-recurrent RM.
• To investigate the evolution of genetic alterations in RM during recurrence.

Main Methods:

• Retrospective analysis of clinical, histopathological, and cytogenetic data from 29 RM tumors.
• Comparison of genetic profiles between primary and recurrent RM samples.
• Assessment of BAP1 loss of expression and chromosomal aberrations (losses and gains).

Main Results:

• BAP1 loss of expression increased from one-third at diagnosis to 100% in subsequent recurrences.
• Non-recurrent RM showed distinct chromosomal losses (19p, 19q) and gains (20, 21) compared to recurrent RM.
• Recurrent RM displayed complex genotypic profiles with extensive losses (1p, 14q, 18p, 18q, 21p) and gains (17q22) at diagnosis, with additional alterations (16q, 19p losses; 1q, 17q gains) upon recurrence.

Conclusions:

• Recurrent rhabdoid meningiomas exhibit distinct and evolving cytogenetic profiles compared to non-recurrent tumors.
• BAP1 loss of expression is a key feature associated with RM recurrence.
• Specific chromosomal alterations may serve as potential biomarkers for predicting RM recurrence risk.