Susanna Marras

Endometrial polyp: another benign tumor characterized by 12q13-q15 changes.

Clustering of aberrations to specific chromosome regions of benign tumors may indicate the location of genes related to the proliferative process. Although few endometrial polyps have been cytogenetically investigated, 6p21 band appears to be involved consistently in the chromosome changes. We report two cases of this type of benign tumor with chromosome rearrangements in 12q14-15, allowing identification of a second cytogenetic subgroup in endometrial polyps.

Molecular cytogenetic characterization of del(7q) in two uterine leiomyoma-derived cell lines.

Uterine leiomyoma cytogenetically exhibits at least six chromosomally abnormal subgroups. The largest subgroup is characterized by deletions of the long arm of chromosome 7. Few molecular and fluorescence in situ hybridization data are available that have aimed at a better definition of the lesion. Here, we report the results of a partial molecular cytogenetic characterization of two del(7q) chromosomes that were derived from cell lines established from two uterine leiomyomas with del(7)(q22q32). By using a large series of ordered 7q markers, we were able to identify the most proximal and the most distal conserved markers, which delineate the size of the deletion and which allow for a more targeted approach to the nature and function of genes that are possibly relevant for the pathogenesis of the disorder. Genes Chromosom. Cancer 18:155–161, 1997.

Cellular fibrous histiocytoma of the skin: Evidence of a clonal process with different karyotype from dermatofibrosarcoma

Recently, a distinct variant of cutaneous fibrous histiocytoma (FH) has been histologically characterized as a “cellular” subtype. This variant is often mistaken for sarcoma, including dermatofibrosarcoma protuberans. We report a case of cellular FH of the skin in which the cytogenetic analysis demonstrated a novel chromosome pattern, possibly allowing distinction from its histologic simulants. Genes Chromosom. Cancer 18:314–317, 1997.

Chromosomal Changes in Dysplastic Nevi

The dysplastic nevus is considered to be a precursor lesion of melanoma, representing one of the first steps in the progressive transformation from normal melanocyte to melanoma. Various risk degrees of developing cutaneous melanoma in patients with dysplastic nevi have been advanced, based on the presence of dysplastic nevi or melanoma or both in members of the patients family. We report on the cytogenetic study of three nevi in a young patient with a family history of melanoma. Each nevus showed a simple clonal chromosome change. The t(6;15)(q13;q21) translocation found in one of them seems of particular significance in view of the fact that a similar one, with breakpoint at 6q13 was reported both in an acquired nevus from a patient with a family history of melanoma and in a case of cutaneous metastatic melanoma. These observations seem to support the hypothesis of the existence of a biological continuum between normal melanocyte and melanoma. Furthermore, the finding of chromosome changes similar to those associated with melanoma reinforces the need for a careful follow-up of patients with dysplastic nevi.

DIAGNOSIS OF CHROMOPHOBE RENAL CELL CARCINOMA BY CHROMOSOMAL ANALYSIS

Chromophobe renal cell carcinoma may pose a differential diagnostic problem by routine histologic examination because it may be misdiagnosed as another type of renal cancer with a totally different clinical behavior. A low DNA content as well as hypodiploidy seem to be associated with this renal tumor subtype. We report a case in which the cytogenetic report was of great value for a correct histologic diagnosis.

Chromosome changes in nonneoplastic tissue: Numerical and structural abnormalities in nasal polyps with atypical stromal cells

Cytogenetic investigation on short-term cultures of 13 nasal polyps disclosed the presence of chromosome aberrations in three cases: one (a recurrence) showed numerical changes; the other two had structural abnormalities, an inv(12)(q15q22) in one case, a der(6)t(6;12)(q22;q15) in the other. The three cases were characterized histologically by the presence of frequent atypical stromal cells, and were positive for vimentin and smooth muscle actin. Of the remaining 10 cases, three were not analyzable, and seven had normal karyotypes, although random structural changes were seen in two of them.

Chromosome changes in renal cell carcinoma.

Cytogenetic studies have provided a great deal of useful information about the biology and diagnosis of renal cell tumors. Particularly papillary and non-papillary tumors seem to be characterized by different cytogenetic patterns. We report the cytogenetic and histologic analysis of 16 renal tumors, 5 of which showed clonal chromosome changes. Most had chromosome abnormalities which have so far been described as specific of particular histopathologic subgroups.

Translocation (8;12)(q13;q15) in a pediatric tumor

A reciprocal translocation, t(8;12)(q13;q15), was found to be the sole karyotypic change in a deep-seated lipogenic tumour in a 3-year-old child. Judging from recent data on the cytogenetic characterization of adipose tumours, this finding seems to support the histopathologic diagnosis of lipoma in spite of foci of atypical cells observed at the histologic examination.