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Background: Cytogenetic studies in meningiomas show that 1p monosomy constitutes an important factor involved in their progression. Genes coding for unspecific alkaline phosphatase (AP-un) are located in this chromosome, in particular in 1p34-p36.1. This enzyme is widely distributed in the body and it is also found in meningiomas. The loss of expression of this enzyme in meningiomas has been associated with the presence of 1p monosomy in these tumors., Patients and Method: We studied 10 meningiomas from 8 patients which shared 1p monosomy. Three tumors had a benign morphologic pattern; it was atypical in two and malignant in five cases. We performed a cytogenetic study and FISH as well as a determination of AP-un in tumor cells., Results: In 8 of ten cases, a loss of AP-un expression was observed. One case displayed positivity in 20% cells. In a positive case, activity was demonstrated in 80% cells., Conclusions: Our work aimed at analysing the relationship between loss of expression of AP-un, 1p monosomy and the aggressiveness of meningioma. Our results back the interest in determining this enzyme in tumor cells as a quick method with important prognostic value.

Background: Cytogenetic studies of meningiomas suggest that loss of (or parts of) chromosome 22 is a primary event in the development of these tumors; later on, other chromosomal changes would occur in the caryotypes. All these secondary changes are observed mainly in cases with high clinical aggressivity. However, in a few cases of meningiomas disomy 22 coexists, but with other chromosomic anomalies. We present clinical, histopathological and cytogenetic findings in a group of meningiomas with disomy of chromosome 22., Patients and Methods: We collected 10 meningiomas from nine patients which ages ranged between 28-70 years. Fresh tumoral specimens were divided for histologic examination and cytogenetic study, performed after short-term culture., Results: At microscopic examination 5 tumors were classified as benign meningiomas, four as atypical and one as malignant meningioma. Four cases were recurrent tumors. The cytogenetic studies showed that all tumors presented two chromosomes 22 and other chromosome abnormalities. Losses in chromosomes 4, 7, 10, 14, 16, 17 and 20 were frequent; cytogenetics rearrangements of chromosomes 1, 4, 5, 7, 14, 19 and 22 were frequently involved., Conclusions: In karyotypic evolution of meningiomas, secondary anomalies of chromosomes 1p, 10 and 14 are the most common and appear to be associated with a more aggressive clinical course. In this group of meningiomas with disomy 22, these anomalies were also frequently found, and were related in 50% of cases with atypical or malignant morphologies and of them with recurrent tumors in the 40%.

A 17-year-old girl was referred to us because of primary amenorrhea and features of Turner's Syndrome. The karyotype obtained from peripheral lymphocytes cultures was mos 45,X/46, XYnf/47, XYnfYnf/46, X, dic (Ynf) (q12). The karyotype of fibroblasts derived from cultures of both gonads was mos 45, X/46, XYnf/47, XYnfYnf. The Y chromosome was non-fluorescent in all the examined lines. We report here the clinical and cytogenetic findings in a patient with an unusual sex chromosome mosaicism.

We present two new cases of Y-autosome translocation which were detected in two azoospermic males. In the first case the translocation was de novo with the karyotype: 46,XY,t(Y;16)(q12;q11-12). In the second case the karyotype was: 46,XY,t(Y;1)(cen-q11;cen-p11), t(Y;15)(q12;p11), the mother having been a carrier of the same Y-15 translocation, and showing the chromosomic formula: 46,XX,t(Y;15)(q12;p11).