Endoglin (CD105) has been shown to be a more useful marker to identify proliferating endothelium involved in tumor angiogenesis than panendothelial markers such as CD31. We investigated endoglin and vascular endothelial growth factor expression as possible prognostic markers in colorectal cancer. Surgical specimens from 150 patients with resected colorectal carcinomas were immunostained for endoglin, CD31 and vascular endothelial growth factor. Colorectal carcinoma cases consisted of 50 cases without lymph node metastases, 50 cases with only lymph node metastases and 50 cases with liver metastases (38 cases also had positive lymph nodes). Positively stained microvessels were counted in densely vascular foci (hot spots) at  400 fields in each specimen. For vascular endothelial growth factor, intensity of staining was scored on a three-tiered scale. Results were correlated with other prognostic parameters. Endoglin demonstrated significantly more proliferating neoplastic microvessels than CD31 (31710 vs 1978/0.15 mm 2 field, Po0.001). Low vascular endothelial growth factor expression within tumor cells was seen in 49 (33%) and high expression in 101 cases (67%). There was a positive correlation of endoglin, CD31 counts and vascular endothelial growth factor overexpression with the presence of angiolymphatic invasion and lymph node metastases (Po0.05). Only endoglin counts correlated significantly with liver metastases and positive vascular pedicle lymph nodes (Po0.05), while vascular endothelial growth factor showed significant correlation with the depth of invasion (Po0.01). Endoglin, by staining higher numbers of the proliferating vessels in colon carcinoma, is a more specific and sensitive marker for tumor angiogenesis than the commonly used panendothelial markers. Endoglin staining also showed prognostic significance with positive correlation with angiolymphatic invasion and metastases to lymph nodes and liver.

Lymph node metastases is an important prognostic indicator for disease progression and crucial for therapeutic strategies in the work-up of colorectal carcinoma. In this study, we investigated tumor lymphangiogenesis and vascular endothelial growth factor (VEGF) expression as predictive markers for the risk of lymph node metastasis and their relation to other prognostic parameters in colorectal carcinoma. Resected colorectal carcinomas from 90 patients were examined, including 30 patients without lymph node metastases, 30 with only lymph node metastases, and 30 with liver metastases. Cases were immunostained for CD31, D2-40, and VEGF. Positivity stained microvessels were counted in densely vascular/lymphatic foci (hot spots) at  400 field ( ¼ 0.17 mm 2 ). Intensity of staining for VEGF was scored on a two-tiered scale. D2-40 lymphatic microvessel density demonstrated significant correlation with CD31 counts (2079 vs 1876/0.17 mm 2 field, Po0.05) and VEGF expression (Po0.01). VEGF was expressed in 61/90 (67%) cases. D2-40 identified lymphatic tumor invasion in 48/90 patients, which was greater than CD31 (37/90) and hematoxylin and eosin (H&E) (31/90). There was a positive significant correlation of D2-40, CD31 counts, and VEGF expression with the presence of lymphovascular invasion and lymph node metastases (Po0.05). D2-40 lymphatic microvessel density correlated significantly with depth of invasion (pT), positive vascular pedicle lymph nodes and liver metastases (Po0.05). In conclusion, D2-40 lymphatic microvessel density showed prognostic significance with positive correlation with lymphovascular invasion, pT, and metastases to lymph nodes and liver. Immunostaining with D2-40 enhances the detection of lymphatic invasion relative to H&E staining and the endothelial marker, CD31.

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Differentiating primary and metastatic hepatic malignancies can be diagnostically challenging in fine-needle aspiration cytology (FNAC). We compared four immunohistochemical (IHC) markers, pCEA, CD10, HepPar1, and CD34, in differentiating hepatocellular carcinoma (HCC) from metastatic carcinoma (MC) in FNAC specimens. Sixty cases of liver FNAC with their corresponding cell blocks were retrieved from the hospital computer system, including 30 HCC and 30 MC (15 colon, 10 breast, and 5 pancreas). The diagnoses were confirmed by clinical follow-up and surgical resection or core needle biopsy. The direct cytologic smears were air-dried and Diff-Quik-stained, and alcohol-fixed and Papanicolaou-stained. Cell block sections from the aspirates were immunostained for pCEA, CD10, HepPar1, and CD34. IHC on cytologic smears for HCC was performed on 10 cases and compared with the cell block results. In HCC, CD10, and pCEA demonstrated the characteristic canalicular staining in 23/30 (77%) and 24/30 (80%) of the cases, respectively; however, none of the MC showed a canalicular staining pattern. HepPar1 was positive in 26/30 (87%) of the HCC cases and one MC. CD34 stained sinusoidal endothelial cells in 27/30 (90%) cases of HCC and six MC. Our results demonstrate that the canalicular staining pattern for CD10 and sinusoidal staining pattern of CD34 are very specific, in addition to the high specificity and sensitivity of HepPar1 for HCC. Cell blocks were more informative in demonstrating the characteristic architecture and immunostaining pattern of the malignancy than the cytologic smears. An IHC panel consisting of pCEA, CD10, HepPar1, and CD34 is useful for confirming HCC in FNAC of the liver.

We studied endoglin and vascular endothelial growth factor (VEGF) expression as prognostic markers in prostatic adenocarcinoma in 50 radical prostatectomy specimens. Cases were further categorized by Gleason score as follows: 8 to 10, 9 cases; 7(4 + 3), 9 cases; 7 (3 + 4), 14 cases; 6, 13 cases; and 4 or 5, 5 cases. All cases were immunostained for endoglin, CD31, and VEGF. Positively stained microvessels were counted in densely vascular foci in a x 400 field. VEGF staining intensity was scored on a 2-tiered scale. Results were correlated with survival and other parameters. Endoglin demonstrated significantly more microvessels than did CD31 (mean +/- SD, 37 +/- 15 vs 22 +/- 17; P < .001). VEGF expression was low in 21 cases (42%) and high in 29 (58%). Endoglin correlated positively with Gleason score, lymph node metastases, tumor stage, and preoperative prostate-specific antigen level (P < .05) but not with CD31. VEGF correlated significantly with angiolymphatic invasion and Gleason score (P < .05). A high endoglin microvessel count and VEGF expression correlated with shorter survival. Endoglin is a more specific and sensitive marker for tumor angiogenesis than CD31 and may serve as a prognostic marker for prostatic adenocarcinoma.

Differentiating reactive mesothelial (RM) proliferation from malignant mesothelioma (MM) can be cytologically challenging. There have been discordant studies reporting the value of epithelial membrane antigen (EMA) in differentiating RM from MM. In this study, we investigated the expression of two different clones of EMA in RM and MM. Twenty cases of pleural effusion smears of RM and 20 cases of MM with their corresponding cell blocks were retrieved from the hospital computer system. Diagnosis of MM was confirmed by surgical decortication or pneumonectomy with immunostaining studies and/or electron microscopy. Cases of RM were confirmed by clinical history and histology. Cell blocks were formalin-fixed, paraffin-embedded, and immunostained for EMA clone Mc5 and EMA clone E29. The positive rates for clone Mc5 were 14/20 (70%) for MM and 12/20 (60%) for RM and EMA clone E29 were 15/20 (75%) for MM and 0/20 (0%) for RM. The sensitivity and specificity for EMA clone Mc5 were 70 and 40%, respectively. For EMA clone E29, the sensitivity and specificity were 75 and 100%, respectively. In conclusion, both RM and MM immunostained for EMA clone Mc5, indicating that it is not a reliable immunocytochemical marker for differentiating RM from MM. EMA clone E29 was negative in all cases of RM and positive in 75% of MM and therefore is a reliable immunocytochemical marker for differentiating RM from MM.

Endoglin (CD105) has been shown to be a more useful marker to identify proliferating endothelium involved in tumor angiogenesis than panendothelial markers such as CD31. We investigated endoglin and vascular endothelial growth factor expression as possible prognostic markers in colorectal cancer. Surgical specimens from 150 patients with resected colorectal carcinomas were immunostained for endoglin, CD31 and vascular endothelial growth factor. Colorectal carcinoma cases consisted of 50 cases without lymph node metastases, 50 cases with only lymph node metastases and 50 cases with liver metastases (38 cases also had positive lymph nodes). Positively stained microvessels were counted in densely vascular foci (hot spots) at  400 fields in each specimen. For vascular endothelial growth factor, intensity of staining was scored on a three-tiered scale. Results were correlated with other prognostic parameters. Endoglin demonstrated significantly more proliferating neoplastic microvessels than CD31 (31710 vs 1978/0.15 mm 2 field, Po0.001). Low vascular endothelial growth factor expression within tumor cells was seen in 49 (33%) and high expression in 101 cases (67%). There was a positive correlation of endoglin, CD31 counts and vascular endothelial growth factor overexpression with the presence of angiolymphatic invasion and lymph node metastases (Po0.05). Only endoglin counts correlated significantly with liver metastases and positive vascular pedicle lymph nodes (Po0.05), while vascular endothelial growth factor showed significant correlation with the depth of invasion (Po0.01). Endoglin, by staining higher numbers of the proliferating vessels in colon carcinoma, is a more specific and sensitive marker for tumor angiogenesis than the commonly used panendothelial markers. Endoglin staining also showed prognostic significance with positive correlation with angiolymphatic invasion and metastases to lymph nodes and liver.

No abstract