Patterns of Chromosomal Abnormalities that Can Improve Diagnosis of Uterine Smooth Muscle Tumors.

Background/aim: Compared to leiomyomas, smooth muscle tumors of uncertain malignant potential (STUMP), and leiomyosarcomas (LMS) originating from the Muellerian duct are very rare. Their molecular pathogenesis remains poorly understood. The present article aims at performing genetic analyses of these tumors that may help assist histopathological examination.

Materials And Methods: Ten tumors (four STUMP and six LMS) were investigated by copy number arrays.

Results: Two tumors, both classified as STUMP were shown to carry MED12 mutations with one of them presenting with a detectable copy number alteration. All other tumors had multiple copy number changes with a clear predominance of losses. Five chromosomal arms (1p, 13q, 14q, 16q, 22q) were affected by overlapping lost segments in at least four tumors including two cases with biallelic losses of the retinoblastoma gene locus.

Conclusion: Besides the general presence of copy number alterations and particular genetic alterations, heterogeneity and ongoing karyotypic evolution indicate malignancy or approaching malignancy.