Abstract. CD34 is commonly used as an endothelial cell marker of tumor vessels. However, this marker detects not only newly formed, but also pre-existing large blood vessels. Nestin, a class VI intermediate filament protein, has recently received attention as a marker for detecting newly formed endothelial cells. In this study, whether nestin is a novel angiogenesis marker in colorectal cancer was examined. HCT-15, a human colon cancer cell line, was subcutaneously implanted into the dorsum of nude mice. After the tumor grew, the mice were perfused with fluorescent beads (Fluospheres). Then, the tumor tissues were used for immunofluorescence staining using nestin and the CD34 antibody. Immunohistochemistry was performed with nestin and CD34 on 101 human colorectal cancer tissue samples. Proliferating endothelial cells were detected immunohistochemically by a proliferating cell nuclear antigen (PCNA) antibody. Clinicopathological factors and prognosis were compared between two groups: that with a microvessel density (MVD) higher than the median MVD and that with MVD lower than the median MVD, as detected by nestin and CD34 labellings. Nestin was localized in endothelial cells in small blood vessels (median, 9.06 μm), whereas CD34 was localized in large blood vessels (median, 9.67 μm) in nude mice. The diameter of nestin-positive vessels was smaller than that of CD34-positive vessels in human colorectal cancer. The number ratio of PCNA-positive cells to nestin-positive vascular endothelial cells was higher than that of PCNA-positive to CD34-positive cells (p=0.002). There were no correlations between nestin-positive blood vessels and clinicopathological factors, but the prognosis was worse in the highly nestin-positive MVD group (p=0.071). Nestin is considered a novel angiogenesis marker of proliferating endothelial cells in colorectal cancer tissue.

Lumican is a member of a small leucine-rich proteoglycan family, and it is reportedly overexpressed in human breast cancer. The expression of lumican in the extracellular matrix in breast cancer is associated with a high tumor grade, low estrogen receptor levels and young age. Lumican expression has been previously reported in colorectal cancer, but the role of lumican in the tumor is not well understood. In this study, we examined the expression and role of lumican in advanced colorectal cancer. Immunohistochemical staining was performed on 158 patients who underwent curative surgery for advanced colorectal cancer with lymph node metastasis. In the normal colorectal tissues, lumican immunoreactivity was observed in the fibroblasts and neural cells, but not in the colorectal epithelial cells. Lumican was localized in the cytoplasm of the cancer cells and its overexpression was detected in 99 of the 158 (62.7%) colorectal cancer patients. Clinicopathologically, there was no association of lumican expression with age, sex, histological typing, or venous and lymphatic invasion. However, lumican expression tended to correlate with the spread of lymph node metastasis and the depth of tumor invasion (p=0.136 and 0.135, respectively). Furthermore, the survival rate was significantly lower in patients with a high lumican expression level than in those with a low lumican expression level (p=0.048). These results indicate that lumican expression is a potential prognostic factor in patients with advanced colorectal cancer with nodal metastasis.

Abstract. Poorly differentiated (PD) adenocarcinoma often retains the capacity for neuroendocrine (NE) cell differentiation; however, it is difficult to distinguish the NE cell differentiation by routine hematoxylin and eosin staining. It is important to detect the presence of NE cell differentiation in advanced colorectal carcinomas because these carcinomas have been shown to produce distant metastasis at the time of diagnosis and to have a particularly poor prognosis. In this study, the characteristics of PD adenocarcinoma with NE cell differentiation and its biological metastatic mechanisms were investigated. Forty-eight of 2204 colorectal cancer patients, diagnosed as having PD adenocarcinoma (2.2%) were enrolled in this study. Immunohistochemical analysis was performed with anti-chromogranin A anti-synaptophysin, anti-CD34, anti-D2-40, and anti-VEGF antibodies. The clinicopathological factors for PD adenocarcinoma with NE cell differentiation were compared with those for PD adenocarcinoma without NE cell differentiation. Microvessel density (MVD) was assessed using immunostained slides with anti-CD34 antibody and vascular endothelial growth factor (VEGF) expression in PD adenocarcinoma with NE cell differentiation was confirmed by in situ hybridization. By immunohistochemical staining for chromogranin A and synaptophysin, NE cell differentiation was detected in eight of 48 patients (16.7%) with PD adenocarcinoma. The frequency of liver metastasis at the time of diagnosis was significantly higher in patients having PD adenocarcinoma with NE cell differentiation (p=0.03). Moreover, MVD and VEGF expression level tended to be higher in patients having PD adenocarcinoma with NE cell differentiation (p=0.13 and 0.068, respectively). NE cell differentiation in PD adenocarcinoma may produce liver metastasis through microvessel formation in the tumor induced by VEGF. In PD colorectal adenocarcinoma, immunohistochemical analysis of NE markers is important for establishing the presence of NE cell differentiation and further study is necessary to evaluate the effectiveness of anti-angiogenic drugs to PD adenocarcinoma with NE cell differentiation.

No abstract

We describe an inflammatory tumor in the Spiegel lobe of the liver of an 81-year-old woman. The patient was referred to our hospital for evaluation of a fever of over 39 degrees C and upper abdominal pain. Both conditions had persisted for five days in spite of antibiotic treatment. Initial laboratory tests revealed a serum C-reactive protein concentration of 20.9 mg/dL and white blood cell count of 15,500/microL. Abdominal ultrasound showed a hypoechoic lesion measuring 4 cm in diameter in the Spiegel lobe of the liver. A follow-up abdominal ultrasound revealed that the hypoechoic lesion was not decreased in size. Computed tomography showed a moderate-to-high-density area in the arterial phase and a low-density area in the Spiegel lobe on delayed phase. Magnetic resonance imaging showed a faint low-intensity lesion on T1-weighted imaging and moderate-to-high-intensity lesion on T2-weighted imaging in the Spiegel lobe. Angiography showed a slight hypervascularity in the area of the Spiegel lobe. Antibiotics and nu-globulin were commenced soon after admission and the fever gradually improved. Ultrasound-guided liver biopsy revealed that the hepatic parenchyma was almost completely replaced by dense hyalinized fibrous tissue and inflammatory cells. These findings were construed to indicate a benign lesion, but the tumor remained unchanged. Malignant disease could not be completely ruled out. Segment 1 of the liver was resected. Macroscopic examination of the resected specimen revealed a gray, fibrotic, solid tumor. The border of the tumor was well-circumscribed but not encapsulated. Microscopically, the tumor showed a marked fibrotic background with infiltration by a mixed population of lymphocytes, plasma cells, histiocytes, and reactive, plump spindle cells. The postoperative course was uneventful. The patient has remained well in the 10 months since the resection without recurrence.