Role of arginase-1 expression in distinguishing hepatocellular carcinoma from non-hepatocellular tumors / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the role of arginase-1 (Arg-1) expression in differential diagnosis of hepatocellular carcinoma (HCC), Arg-1 staining pattern in clear cell neoplasm (HCC and non-HCC) and Arg-1 expression in non-hepatocellular tumors.</p><p><b>METHODS</b>Seventy-eight cases of HCC (including 8 cases of clear cell type and 70 cases of non- clear cell type) and 246 cases of non-hepatocellular neoplasms (including 29 cases of metastatic tumors such as breast cancer, nasopharyngeal carcinoma and neuroendocrine carcinoma, 77 cases of tumors with clear cell changes such as malignant melanoma, clear cell renal cell carcinoma and alveolar soft part sarcoma, and 140 cases of other types of tumors such as ovarian endometrioid adenocarcinoma, pituitary tumor and thyroid papillary carcinoma) were studied.Immunohistochemical study for Arg-1 was performed on the paraffin-embedded tumor tissue.</p><p><b>RESULTS</b>In HCC, Arg-1 demonstrated both cytoplasmic and nuclear staining, with an overall sensitivity of 96.2% (75/78).In well, moderately and poorly differentiated HCC, the sensitivity was 15/15, 100% (41/41) and 86.4% (19/22), respectively. That was in contrast to negative staining for Arg-1 in all the 29 cases of metastatic tumors studied. The sensitivity, specificity, positive predictive value and negative predictive value of Arg-1 in distinguishing HCC from metastatic tumors was 96.2%, 100%, 100% and 90.6%, respectively. Cytoplasmic and membranous staining was observed in clear cell type of HCC. The overall sensitivity of Arg-1 expression in the 77 cases of tumors with clear cell changes was 14.3% (11/77), including 8/15 for malignant melanoma, 2/4 for ovarian clear cell carcinoma and 1/1 gall bladder adenocarcinoma with clear cell component.In malignant melanoma and ovarian clear cell carcinoma, only cytoplasmic staining was demonstrated. There was no expression of Arg-1 in the 140 cases of other tumor types studied.</p><p><b>CONCLUSIONS</b>Arg-1 is a sensitive and specific marker for HCC.It is a potentially useful immunohistochemical marker in distinguishing HCC from metastatic tumors. Though also expressed in malignant melanoma and ovarian clear cell carcinoma, Arg-1 shows a different staining pattern as compared with that in HCC.</p>

Clinicopathologic significance of β-catenin protein and loss of heterozygosity on 10q in medulloblastoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the expression of β-catenin protein and the status of loss of heterozygosity (LOH) on chromsome 10q in medulloblastoma, with clinical correlation.</p><p><b>METHODS</b>Immunohistochemical study for β-catenin protein was carried out in 50 cases of medulloblastoma encountered in the First Affiliated Hospital of Xinjiang Medical University during the period from 2002 to 2011, including 32 cases of classic medulloblastoma, 13 cases of desmoplastic medulloblastoma and 5 cases of medulloblastoma with extensive nodularity. The status of LOH on 10q was also detected by fluorescence in-situ hybridization. The clinicopathologic characteristics and prognostic parameters were studied by Kaplan-Meien and Cox analysis.</p><p><b>RESULTS</b>The rates of expression of β-catenin protein in classic medulloblastoma, desmoplastic medulloblastoma and medulloblastoma with extensive nodularity were 53.1% (17/32), 4/13 and 1/5, respectively. The rate of LOH on 10q was 33.3% (8/24) in classic medulloblastoma and 2/11 in desmoplastic medulloblastoma. There was no statistically significant difference between the two tumor types. Univariate analysis showed that the expression of β-catenin protein (P = 0.022), lack of LOH on 10q (P = 0.020), extensiveness of tumor resection (P < 0.01), radiotherapy (P = 0.002) and chemotherapy (P < 0.01) represented important prognostic factors.</p><p><b>CONCLUSIONS</b>Medulloblastoma with expression of β-catenin protein and without LOH on 10q carries a better prognosis. Assessment of these parameters is helpful in evaluating prognosis and subsequent patient management.</p>