TMPRSS2-ERG gene fusion in small cell carcinoma of the prostate.

Recent studies have shown that most prostate cancers carry the TMPRSS2-ERG gene fusion. Here we evaluated the TMPRSS2-ERG gene fusion in small cell carcinoma of the prostate (n = 12) in comparison with small cell carcinoma of the urinary bladder (n = 12) and lung (n = 11). Fluorescence in situ hybridization demonstrated rearrangement of the ERG gene in 8 cases of prostatic small cell carcinoma (67%), and the rearrangement was associated with deletion of the 5' ERG gene in 7 cases, but rearrangement of the ERG gene was not present in any small cell carcinoma of the urinary bladder or lung. Next we evaluated the TMPRSS2-ERG gene fusion in nude mouse xenografts that were derived from 2 prostatic small cell carcinomas carrying the TMPRSS2-ERG gene fusion. Two transcripts encoded by the TMPRSS2-ERG gene fusion were detected by reverse transcriptase polymerase chain reaction, and DNA sequencing demonstrated that the 2 transcripts were composed of fusions of exon 1 of the TMPRSS2 gene to exon 4 or 5 of the ERG gene. Our study demonstrates the specific presence of TMPRSS2-ERG gene fusion in prostatic small cell carcinoma, which may be helpful in distinguishing small cell carcinoma of prostatic origin from nonprostatic origins. The high prevalence of the TMPRSS2-ERG gene fusion in prostatic small cell carcinoma as well as adenocarcinoma implies that small cell carcinoma may share a common pathogenic pathway with adenocarcinoma in the prostate.

Expression of master regulatory genes controlling skeletal development in benign cartilage and bone forming tumors.

Recent progress in skeletal molecular biology has led to the clarification of the transcriptional mechanisms of chondroblastic and osteoblastic lineage differentiation. Three master transcription factors-Sox9, Runx2, and Osterix-were shown to play an essential role in determining the skeletal progenitor cells' fate. The present study evaluates the expression of these factors in 4 types of benign bone tumors-chondromyxoid fibroma, chondroblastoma, osteoid osteoma, and osteoblastoma-using immunohistochemistry and tissue microarrays. Osteoid osteoma and osteoblastoma showed strong nuclear expression of Osterix and Runx2. In contrast, only a few chondroblastomas showed positive nuclear expression of Osterix. Strong nuclear expression of Sox9 was detected in all chondroblastomas, whereas nearly half of the osteoblastomas showed focal weak cytoplasmic expression of Sox9.

Expression of Galectin-3 in renal neoplasms: a diagnostic, possible prognostic marker.

CONTEXT: Galectin-3, a member of the lectin family, was shown to be expressed in normal distal tubular cells and in renal cell carcinomas (RCC). However, its diagnostic and prognostic significance in RCC is as yet undefined. OBJECTIVES: To describe the expression of Galectin-3 among different histologic subtypes of renal neoplasms and to determine their diagnostic and prognostic significances. DESIGN: The expression of Galectin-3 was evaluated in 217 renal neoplasms by tissue microarray and immunohistochemistry with semiquantitative analysis. RESULTS: Strong expression of Galectin-3 was observed in 92 of 217 of renal neoplasms (42.4%). Although 22 of 23 oncocytomas (95.7%) and 19 of 21 chromophobe RCCs (90.5%) express Galectin-3, only 4 of 32 papillary RCCs (12.5%) and 47 of 137 clear cell RCCs (34.3%) express Galectin-3, suggesting that it may be used as a potential diagnostic marker. Galectin-3 expression was seen in 55% of high-grade (Fuhrman nuclear grades 3 and 4) versus 21% low-grade (grades 1 and 2) clear cell RCCs (P < .001). CONCLUSIONS: This study confirms that Galactin-3 is strongly overexpressed in renal cell neoplasms of distal tubular differentiation, that is, oncocytoma and chromophobe RCCs, suggesting it might be used as a possible differential diagnostic tool for renal cell neoplasm with oncocytic or granular cells. Furthermore, we observed a strong association of overexpression of Galectin-3 and high nuclear grade in clear cell RCC. These results also suggest a possible pivotal role for Galectin-3 in the differentiation and prognosis of clear cell RCC.

Clinicopathologic study of 24 patients with primary cardiac sarcomas: a 10-year single institution experience.

Primary cardiac sarcomas are exceptionally rare. We present a 10-year, single-institution experience with 24 primary adult cardiac sarcomas. These cases were retrieved from the Department of Pathology data file of the Methodist Hospital at Houston, TX. Clinical presentation and pathologic features were analyzed. Histologic classification was followed according to the criteria set by the World Health Organization, and grading according to the system proposed by the Federation Nationale des Centres de Lutte Contrele Cancer. There were 14 men and 10 women (male/female, 1.4:1) with a mean age of 42.2 years (range 20-68 years). The tumors involved the right atrium in 14 cases, left atrium in 6 cases, right ventricle in 2 cases, and left ventricle in 2 cases. The tumor size ranged from 2.0 to 17.0 cm (mean 7.2 cm), and, histologically, there were 10 angiosarcomas, 9 unclassified sarcomas, 3 synovial sarcomas, and 2 leiomyosarcomas. All 10 angiosarcomas originated from the right atrium, whereas 5 of the unclassified sarcomas were from the left atrium. Although cases were limited, no predilection site was found for the other histologic types. All tumors were graded as 2 (5 cases) or 3 (19 cases) in differentiation. The prognosis was poor with a median survival time of 25 months after diagnosis. The grade was not statistically significant on survival (P = .14). In conclusion, angiosarcoma and unclassified sarcomas are the most common sarcomas of the heart accounting for 76%, but rare tumors such as synovial sarcoma and leiomyosarcoma may also occur in this organ. The survival of cardiac sarcomas is poor.