Endometrial stromal sarcomas: immunohistochemical, electron microscopical and cytogenetic findings in two cases

Abstract

Uterine sarcomas are approximately 3% of all malignant uterine corpus tumours. Of these, the tumours that originate solely in the stromal elements of the uterine wall are infrequent and have not been well characterized cytogenetically. We report two cases of endometrial stromal sarcomas (ESS), one low grade and one high grade, diagnosed by conventional histology, immunocytochemistry, electron microscopy and cytogenetics. Morphologically clear-cut differential structures were seen at optical, immunohistochemical, and electron microscopic levels, permitting a clear differential diagnosis. The low-grade ESS expressed hormonal receptors and vimentin, whereas the high-grade ESS showed no hormone receptors, high Ki-67 activity, and occasional cytokeratin-positive cells. Ultrastructurally, no malignant epithelial differentiation was seen in the tumour cells, but cilia were found in both cases. Cytogenetic study of the low-grade ESS showed pseudodiploid karyotype with chromosomes 6 and 20 rearranged. The high-grade ESS showed a complex karyotype with clonal numerical and structural anomalies. The chromosomes involved in the structural rearrangements were 1, 3, 6, 7, 13, 14, 15, 17, 19, and 21.

Utility of CD10 in Distinguishing between Endometrial Stromal Sarcoma and Uterine Smooth Muscle Tumors: An Immunohistochemical Comparison of 34 Cases

“…The lack of a unique immunohistochemical profile for ESS further hampers diagnostic efforts. Cytogenetic studies have not shown consistent chromosomal abnormalities and thus, their utility in the diagnosis of ESS is limited (5,12).…”

Pathogenetic mechanisms in endometrial stromal sarcoma

“…In addition to the 7; 17-translocation, chromosomal band 7 ϳ p21 ] p15 was found rearranged in seven ESS with other partners than chromosome 17 (Laxman et al, 1993;Hrynchak et al, 1994;Iliszko et al, 1998;Gil-Benso et al, 1999;Micci et al, 2003Micci et al, , 2006 suggesting that alternative, pathogenetically equivalent variant translocations exist in this tumor type. Indeed, the first such variant, a t(6; 7), was recently described in two ESS in which a der(7)t(6; 7)(p21;p15)del(6)(q21) and a der(7)(7qter ] 7p15::6?::15?::3?…”

“…The PHF1 gene is located in chromosomal band 6p21, which is the third most commonly rearranged band in ESS, involved as it is in ten of altogether 34 reported tumors and with different translocation partners (Fresia et al, 1992;Laxman et al, 1993;Hrynchak et al, 1994;Fuzesi et al, 1995;Gil-Benso et al, 1999;Sonobe et al, 1999;Micci et al, 2003Micci et al, , 2006. In four cases, it was recombined with chromosomal region 7p ϳ p22 ] p15 and in two of these, the already mentioned JAZF1/PHF1 fusion gene was identified (Micci et al, 2006).…”

“…Cytogenetic studies of ESS are few with only 34 tumors having been karyotyped and scientifically reported (Dal Cin et al, 1988Havel et al, 1989;Fletcher et al, 1991;Sreekantaiah et al, 1991;Fresia et al, 1992;Laxman et al, 1993;Hrynchak et al, 1994;Fuzesi et al, 1995;Pauwels et al, 1996;Hennig et al, 1997;Iliszko et al, 1998;Gil-Benso et al, 1999;Sonobe et al, 1999;Koontz et al, 2001;Amant et al, 2003a;Leunen et al, 2003;Micci et al, 2003Micci et al, , 2006Satoh et al, 2003). Although a variety of different chromosomal aberrations have been described, the pattern of their occurrence is nevertheless clearly nonrandom with particularly frequent involvement of chromosome arms 6p, 7p, and 17q (Micci et al, 2003).…”

The cytogenetics and molecular biology of endometrial stromal sarcoma

“…In one tumor (Iliszko et al, 1998), there were three different 7p rearrangements, described as der(2)t(2; 7), del(7)(p15p13) and der(7), resulting from an unbalanced t(7; 17). Another tumor with an add(7)(p21) (Gil-Benso et al, 1999) and a case in which both chromosomes 7 were involved in complex rearrangements at 7p15 have been described. The involvement of the same bands 7p21 ϳ p15 in six cases without a t(7; 17) (p21 ϳ p15;q12 ϳ q21), suggests that this region may be pathogenetically involved in ESS tumorigenesis in more than one way.…”