monosomy 3
Loss of one copy of chromosome 3 in uveal melanoma cells, associated with poor prognosis and high metastatic risk.
Full Definition
Monosomy 3 refers to the complete or partial loss of one copy of chromosome 3 in uveal melanoma tumor cells, representing one of the most significant prognostic markers in ocular oncology. This chromosomal aberration is detected in approximately 50% of uveal melanomas and is strongly associated with larger tumor size, epithelioid cell morphology, and dramatically increased risk of systemic metastasis. Patients with monosomy 3 tumors have a 5-year metastasis rate of approximately 70% compared to less than 5% for disomy 3 tumors. Detection of monosomy 3 status is typically performed using fluorescence in situ hybridization (FISH) or comparative genomic hybridization and has become integral to risk stratification and surveillance protocols for uveal melanoma patients.
Usage
Usage note: Report as percentage of cells affected when providing cytogenetic results.
In Context
- "Cytogenetic analysis revealed monosomy 3 in 85% of tumor cells, indicating high-risk disease." — Molecular pathology report
- "The patient with monosomy 3 uveal melanoma was enrolled in an intensive surveillance program for metastasis detection." — Oncology follow-up plan