Ring (13)(p11q34) as the sole abnormality in a leiomyosarcoma of the small bowel

Cytogenetic abnormalities in primary bronchopulmonary leiomyosarcoma of childhood

Primary bronchopulmonary leiomyosarcoma (PBLMS) is a rare malignant neoplasm in all age groups and only 10 pediatric cases of PBLMS have been reported. This report presents cytogenetic findings of a PBLMS from an 8-year-old boy. Tumor diagnosis was established by using routine histopathology, immunohistochemistry, and electron microscopy. The karyotype was highly complex, demonstrating consistent structural abnormalities of chromosomes 1, 5, 6, and 7, relative gain of chromosomes 2 and 11, and relative loss of chromosomes 9, 19, 20, and 22, along with the presence of multiple marker chromosomes. Cytogenetic results of previously reported leiomyosarcomas are reviewed and compared with the present case.

Cytogenetics of tumors of soft tissue and bone. Implication for pathology

Pathologists should be aware of the existence of diagnostically useful chromosomal rearrangements in several soft tissue and bone tumors. They include rearrangement of 8q12 in lipoblastomas, ring chromosomes in atypical lipomas, ring and giant marker chromosomes in well differentiated liposarcomas, t(12;16)(q13;p11) in myxoid liposarcomas, rearrangement of 7p21-22 in low-grade endometrial stromal sarcomas, t(2;13)(q37;q14) in alveolar rhabdomyosarcomas, t(X;18)(p11.2;q11.2) in synovial sarcomas, t(12;22) (q13;q13) in clear cell sarcomas, t(11;22)(q24;q12) in Ewing's sarcomas and peripheral neuroepitheliomas, and t(9;22)(q21-31;q11-12) in extraskeletal myxoid chondrosarcomas.

Recurrent chromosome aberrations in abdominal smooth muscle tumors

Short-term cultures of four abdominal smooth muscle tumors, three leiomyosarcomas and one leiomyoma, were analyzed cytogenetically. A low-grade malignant, epithelioid leiomyosarcoma had a normal karyotype. The other two leiomyosarcomas had abnormal karyotypes; one was near-diploid, and the other was near-triploid. Structural rearrangements of the short arm of chromosome 16 and monosomies of chromosomes 14, 15, and 22 were observed in both tumors. When our cases and previously published abdominal leiomyosarcomas are viewed in conjunction, loss of chromosomes 14, 15, and 22 are the most frequent abnormalities. The leiomyoma, the second cytogenetically abnormal nonuterine leiomyoma reported to date, had a hyperdiploid karyotype with a chromosome number of 56 and structural rearrangements of chromosomes 9, 14, and 19. The only aberrations similar to those observed in the previously reported esophageal leiomyoma were trisomies of chromosomes 7 and 8.

Benign mixed tumor of canine mammary gland showing an r(X) and trisomy 5 as the only clonal abnormalities

We report a benign mixed tumor of the canine mammary gland which showed an r(X) and trisomy 5 as the only clonal karyotypic deviations. Clonal aberrations were observed in 79 of 160 of the metaphases. Of these, 48 cells had both the r(X) and trisomy 5, whereas the remaining metaphases were characterized by the r(X) as the only clonal aberration. We conclude that formation of the ring chromosome was the first abnormality, followed by trisomy 5 during the course of karyotypic evolution.