Molecular cytogenetic analysis of human spermatocytic seminomas

Abstract

We performed comparative genomic hybridization (CGH) on 8 formalin-fixed, paraffin wax-embedded primary spermatocytic seminomas (SS) from 7 patients, one of whom developed metastatic disease. In general, this tumour type is not associated with development of metastases. Since there are only few reported cases of metastatic SS in the literature, this study is the first report of chromosomal constitution in a patient with metastatic disease. Chromosomal imbalances were observed in all 8 tumours analysed by CGH. Frequent copy number alterations were enh(9), dim(16 or 16p), enh(20) and enh(X), each in 6 samples, followed by dim(7) in 4, and enh(1), enh(18) and dim(15), each in 3 samples. In addition to the CGH analysis, interphase fluorescence in situ hybridisation (I-FISH) was applied to evaluate the CGH results and to define the size of the aberrant cell population. Interphase cytogenetics showed gain of material on chromosomes 9 and X in all tumours analysed. Overall, the I-FISH results were in agreement with the CGH data. In conclusion, gain of chromosome 9 seems to be restricted to SS and point to an important role for this aberration in the development of this tumour type.

Genomic and Expression Profiling of Human Spermatocytic Seminomas: Primary Spermatocyte as Tumorigenic Precursor andDMRT1as Candidate Chromosome 9 Gene

“…Gain of the short arm of chromosome 12 is the consistent finding in seminomas/ dysgerminomas (see refs. 18, 19 for review), whereas additional copies of chromosome 9 has been found in all spermatocytic seminomas studied to date (15,16).…”

Management of Low-Stage Testicular Seminoma

“…5,7 Spermatocytic seminoma is rare (<1% of germ cell tumors [GCTs]), originates from more mature germ cells compared with classic seminoma, and has entirely different genetic and morphologic signatures. 8,9 These tumors are also unique because cryptorchidism is not a risk factor and they typically present in older men (mean age at diagnosis, 54 years). 10 Microscopy shows 3 distinct cell types (small, medium, and large) with round nuclei and no placental alkaline phosphatase expression.…”

Spermatocytic Seminoma

“…Comparative genomic hybridization and interphase fluorescent in situ hybridization have shown that gain of chromosome 9 is common in spermatocytic seminoma. 8,21 Differential Diagnosis…”

“…Another case has been reported to have metastasized to lymph nodes, but no photomicrographs were published to document the case. 8 Spermatocytic seminoma has been associated with a testicular sarcoma in approximately a dozen cases. Most of these patients have died of metastases within a few months.…”