Bone marrow (BM)-derived hematopoietic cells, which are major components of tumor stroma, determine the tumor microenvironment and regulate tumor phenotypes. Cyclooxygenase (COX)؊2 and endogenous prostaglandins are important determinants for tumor growth and tumor-associated angiogenesis; however, their contributions to stromal formation and angiogenesis remain unclear. In this study, we observed that Lewis lung carcinoma cells implanted in wild-type mice formed a tumor mass with extensive stromal formation that was markedly suppressed by COX-2 inhibition, which reduced the recruitment of BM cells. Notably, COX-2 inhibition attenuated CXCL12/CXCR4 expression as well as expression of several other chemokines. Indeed, in a Matrigel model, prostaglandin (PG) E 2 enhanced stromal formation and CXCL12/CXCR4 expression. In addition, a COX-2 inhibitor suppressed stromal formation and reduced expression of CXCL12/CXCR4 and a fibroblast marker (S100A4) in a micropore chamber model. Moreover, stromal formation after tumor implantation was suppressed in EP3 ؊/؊ mice and EP4 ؊/؊ mice, in which stromal expression of CXCL12/ CXCR4 and S100A4 was reduced. The EP3 or EP4 knockout suppressed S100A4 Recent advances in tumor biology have identified the stroma as an important regulator of carcinogenesis and a potentially valuable therapeutic target. Although interactions between the epithelium and stroma have long been considered to be important in tumor progression, the efficacy of targeting stromal components as a therapeutic strategy has not been established, because the specific regulators of such interactions remain unclear. In addition to endothelial cells, macrophages and fibroblasts 1 are the major stromal components of the tumor microenvironment, and they play key roles in the enhancement of angiogenesis. It has recently been established that bone marrow (BM)-derived hematopoietic cells are the major components of the stroma of tumors, and that they determine the tumor microenvironment [2][3][4][5][6][7][8] ; however, the specific factors that enhance the functions of BM-derived precursor cells, and the mechanism of recruitment of these cells during tumor angiogenesis, are not fully understood. Tumor-associated angiogenesis in the tumor stroma is a prerequisite for invasive growth of a tumor larger than 2 to 3 mm in diameter, and then metas-

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The miniprobe can be useful for therapeutic decision-making in submucosal invasive colorectal cancer.

Treatment with a low dose of nab-paclitaxel once every 3 weeks was tolerable and of acceptable safety and might be beneficial for patients with metastatic or recurrent breast cancer.

Epidermoid cysts arising in an intrapancreatic accessory spleen are exceedingly rare, furthermore the natural course of them is hardly known. We report a case correctly diagnosed with epidermoid cyst in an intrapancreatic accessory spleen, followed by 1 year observation, finally underwent surgical treatment. The patient presented with diarrhea. Contrast-enhanced computed tomography (CT) revealed a pancreatic cyst 20 mm in diameter, surrounded by a solid component showing the same enhancement as the spleen, suggesting the presence of an epidermoid cyst in an intrapancreatic accessory spleen. One year later, back discomfort developed, and a CT scan revealed that the cyst had grown to 38 mm in diameter. To obtain a definitive diagnosis, we performed a laparoscopic spleen-preserving distal pancreatectomy. The histopathological diagnosis was compatible with an epidermoid cyst in an intrapancreatic accessory spleen, which is benign. The postoperative course was uneventful. This case demonstrates that an epidermoid cyst arising in an intrapancreatic accessory spleen can rapidly grow, even if it is benign. Laparoscopic spleen-preserving distal pancreatectomy can be a useful procedure, with the advantages of low invasiveness and organ preservation, for the treatment of benign or low-grade malignant tumors located in the pancreatic body or tail.

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BackgroundHepatic angiomyolipomas are a rare, benign group of mesenchymal tumors in the liver. Hepatic angiomyolipoma is sometimes misdiagnosed as hepatocellular carcinoma, and there is the possibility of a malignant transformation. Hence, the accurate diagnosis of this disorder is necessary.Case presentationA 64-year-old Japanese man was observed to have a space-occupying lesion of 15-mm diameter in the liver during a follow-up examination for a previously resected cecal carcinoma. He underwent lateral segmentectomy of the liver with a provisional diagnosis of hepatic metastatic recurrence of the carcinoma based on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging and diffusion-weighted imaging.ConclusionsWe have explored the combination of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging and histological examination to confirm our diagnosis of hepatic angiomyolipoma comprising an intimate mixture of numerous abnormal blood vessels, adipocytes, and epithelioid spindle cells of various sizes. Immunohistochemical examination revealed characteristic pathological findings associated with positive qualitative immunoreactions for human melanoma black 45 and desmin. Electron microscopic findings revealed the presence of melanosomes in the epithelioid cells. Diffusion-weighted imaging provides a more accurate diagnostic image with the characteristic macroscopic appearance of hepatic angiomyolipoma. Through immunohistochemistry and electron microscopy, we also show that this benign tumor comprises tissue elements.

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