Interphase Fluorescence In situ Hybridization Analysis of Chromosome 12p Abnormalities Is Useful for Distinguishing Epidermoid Cysts of the Testis from Pure Mature Teratoma

Abstract

Purpose: The distinction of epidermoid cyst of the testis from teratoma is of critical importance because the former is benign and the latter is a malignant tumor that may have associated metastasis of either teratomatous or non^teratomatous germ cell tumor types. Chromosome 12p abnormalities are seen in the vast majority of testicular germ cell tumors of adults and are present in all histologic subtypes. In this study, we investigated the clinical utility of interphase fluorescence in situ hybridization (FISH) analysis of chromosome 12p abnormalities for distinguishing epidermoid cysts of the testis from pure mature teratoma. Experimental Design: Sixteen testicular epidermoid cysts and 17 testicular teratomas were investigated for isochromosome 12p [i(12p)] and 12p overrepresentation using interphase FISH analysis. Results: Neither i(12p) nor 12p overrepresentation were observed in 16 epidermoid cyst cases, whereas i(12p) was detected in 76% of teratomas and 12p overrepresentation was identified in 29% of teratomas. Overall, 88% of testicular teratomas had chromosome 12p abnormalities. Conclusions: FISH identification of i(12p) and/or 12p overrepresentation in routinely processed surgical specimens is a useful ancillary diagnostic tool in distinguishing testicular epidermoid cysts from teratoma.

Multilocular cystic renal cell carcinoma is a subtype of clear cell renal cell carcinoma

“…The method of analysis was partially described previously. [12][13][14][15][16][17][18][19][20] In brief, for each slide, 100-150 nuclei from tumor tissue were scored for signals from probes under the fluorescence microscope with x1000 magnification. Nonneoplastic renal cortex was used as control tissue.…”

Molecular genetic evidence supporting the neoplastic nature of fibrous stroma in testicular teratoma

“…We analyzed the spatial distribution of the green and red signals to detect the specific patterns of signal aggregation consistent with i(12p), as previously reported. [10][11][12][13][14][15][16][17] The quantitative criteria to determine 12p overrepresentation were described previously. [10][11][12][13][14][15][16][17] Classical seminoma specimens with known positive i(12p) and 12p overrepresentation was used as a positive control for FISH analyses.…”

“…5,[9][10][11][12][13][14][15][16] Thus, chromosome 12p alterations are clinically relevant markers for tumors of germ cell origin. Multiple molecular and genetic studies show that testicular teratomas share the same chromosome 12p abnormalities that are observed in all histological subtypes of the vast majority of testicular germ cell tumors.…”

Interphase cytogenetic analysis with centromeric probes for chromosomes 1, 2, 6, 10, and 17 in 11 tumors from a patient with bilateral renal oncocytosis

“…Fluorescence In Situ Hybridization Analysis FISH was performed as described previously [10][11][12][13][14][15][16][17] with centromeric a-satellite DNA probes for chromosome 1 (centromeric enumeration probe (CEP) 1, spectrum orange), chromosome 2 (CEP 2, spectrum orange), chromosome 6 (CEP 6, spectrum green), chromosome 10 (CEP 10, spectrum green), and chromosome 17 (CEP 17, spectrum orange) (Figure 2). All the probes were from Vysis (Vysis, Downers Grove, IL, USA).…”