Intratumoral cytogenetic heterogeneity in a benign neoplasm

Area of Science:

• Cytogenetics
• Oncology
• Pathology

Background:

• A 64-year-old male presented with a rapidly growing left groin mass.
• Histopathologic diagnosis was lipoma with atypia.

Observation:

• Cytogenetic analysis was performed on both incisional biopsy and excised tumor specimens.
• The initial biopsy showed normal cells and three distinct clones with chromosomal aberrations, including translocations and an extra ring chromosome.
• The excised specimen exhibited a normal male karyotype alongside a predominant clone with different translocations and an extra ring chromosome.

Findings:

• The study identified specific chromosomal abnormalities, such as translocations (e.g., t(12;21), t(2;12), t(19;20), t(3;11)) and the presence of ring chromosomes (+r).
• A shift in the predominant clonal karyotype was observed between the initial biopsy and the excised specimen.
• Polyploid cells with large markers, rings, and frequent telomeric associations were also noted, suggesting genomic instability.

Implications:

• The observed chromosomal aberrations may contribute to the atypical features and growth of the lipoma.
• Understanding these cytogenetic changes is crucial for accurate diagnosis and potentially predicting tumor behavior.
• Further research into the role of these specific genetic alterations in lipoma development is warranted.