Tatsushi Suwa

Magnetic resonance imaging of esophageal squamous cell carcinoma using magnetite particles coated with anti-epidermal growth factor receptor antibody

A highly specific and effective magnetic resonance imaging (MRI) contrast agent was prepared by coating super‐paramagnetite particles with monoclonal antibodies (MAbs) directed against epidermal growth factor receptors (EGFRs), which are over‐expressed in esophageal squamous cell carcinoma. The preparation maintained both the immuno‐reactivity of the MAbs and the full relaxing capability of the magnetite particles. The particles of this EGFR‐specific contrast agent are 13.2 ± 1.9 nm in size, and thus, it is assumed that they are smaller than capillary pores and, hence, able to escape scavenging by reticulo‐endothelial system cells. The EGFR‐specific T2‐relaxing ability of this contrast agent was ascertained first in vitro, using the EGFR‐expressing cell line TE8 and the EGFR‐deficient cell line H69. The results in athymic rats bearing TE8 or H69 tumors revealed that the agent has EGFR‐specific MRI contrast capacity in vivo. The electron‐microscopic findings in TE8 tumor‐bearing rats revealed that the magnetite particles had been taken up by their lysosomes. In conclusion, immuno‐specific MRI using magnetite particles coated with MAbs against EGFR appears to be useful in the diagnosis of squamous cell carcinoma of the esophagus. Int. J. Cancer 75:626–634, 1998.

Pancreatobiliary Fistula Associated with an Intraductal Papillary-Mucinous Pancreatic Neoplasm Manifesting as Obstructive Jaundice : Report of a Case

We report a pancreatobiliary fistula caused by an intraductal papillary-mucinous pancreatic neoplasm (IPMN), manifesting as obstructive jaundice. Computed tomography showed dilatation of the bile duct and main pancreatic duct, with multiple cystic masses in the head of the pancreas. Endoscopic retrograde pancreatocholangiography showed a patulous papilla with mucin secretion. Contrast enhancement outlined amorphous material obstructing the lower part of the common hepatic duct. Pancreatogram and magnetic resonance cholangiopancreatography showed diffuse dilatation of the main pancreatic duct and side branches without communication with the adjacent organs or duct. We performed pancreaticoduodenectomy for IPMN of the pancreatic head and a tumor-like lesion in the lower common bile duct (CBD). Macroscopically, impacted thick mucus protruded into the CBD from the pancreas via a pancreatobiliary fistula. Histologic examination revealed a pancreatobiliary fistula caused by intraductal papillary-mucinous carcinoma of the pancreas with mucin hypersecretion, an adenoma without interstitial infiltration, and isolated implantation of an IPMN in the bile duct mucosa around the fistula.

Advanced gastric endocrine cell carcinoma with distant lymph node metastasis: a case report and clinicopathological characteristics of the disease

Gastric pure endocrine cell carcinoma (ECC) is extremely rare. ECC occasionally shows multidirectional differentiation; that is, adenocarcinomatous and/or squamous proliferation. Because gastric ECC has aggressive biological behavior and shows frequent metastasis to liver and lymph nodes even in the early stage, the prognosis of patients having this disease is extremely poor. We treated a 75-year-old woman with advanced gastric pure ECC with total gastrectomy and lymph node dissection, and reviewed all the previously reported cases of this disease. We compared the clinicopathological findings of ECC with those of gastric carcinoma (GC) and found that ECC had significantly more frequent invasion to lymphatic and vascular lumens (P ≪ 0.01) and more frequent metastasis to lymph nodes (P ≪ 0.01) and liver (P ≪ 0.05) compared to GC. Gastric ECC smaller than 5 cm in the greatest dimension showed a higher percentage of advanced lesions (≫T2) than GC (P ≪ 0.05), which could result in the difficulty of finding early ECC. The findings of the analyses we made in this report may account for the poor prognosis of this disease.

Is histopathological evidence really essential for making a surgical decision about mucinous carcinoma arising in a perianal fistula? Report of a case.

We report an unusual case of mucinous adenocarcinoma of the anus associated with a chronic anal fistula, treated successfully by abdominoperineal resection (APR). Although multiple biopsies failed to reveal any histological evidence of malignancy, cancer was diagnosed from the mucin obtained for cytology. Subsequent histological examination of the resected specimen revealed clusters of cancer cells floating in a mucous lake, suggesting that it would have been difficult to acquire the cells in a biopsy sample. Conversely, the presence of mucin lakes and globules in specimens drained from the region of perianal sepsis may have been histologically informative for diagnosis. Thus, although biopsy of the lesion is undoubtedly essential for diagnosis, it often fails to provide enough information to make a definite diagnosis of mucinous carcinoma. This case illustrates that clinicians should base their decision on whether to perform surgery on clinical manifestations, imaging findings, and cytology of mucin obtained by drainage when it is difficult to obtain malignant cells by biopsy.

Case report: lymphangioma of the oesophagus endoscopically resected.

Lymphangioma of the oesophagus is an extremely rare entity, with only nine cases having been reported worldwide. We report on a 52‐year‐old woman with oesophageal lymphangioma, diagnosed using endoscopic ultrasonography and endoscopically resected. No case of malignant transformation of the lymphangioma has been reported in the literature. Endoscopic resection seems to be a minimally invasive method that is appropriate both for the removal of the tumour and precise diagnosis.

Immunosuppressive and Anticancer Effect of a Mammalian Ribonuclease that Targets High-affinity Interleukin-2-receptors

OBJECTIVE To target high-affinity interleukin (IL)-2 receptors involved in lymphocyte proliferation processes such as allograft rejection, autoimmune disorders, and certain haematological malignancies, using a minimally immunogenic mammalian-derived enzyme, bovine RNaseA, which becomes cytotoxic on entering cytoplasm. DESIGN Laboratory study. SETTING Teaching hospital, Japan. MATERIAL Human lymphocytes isolated from healthy histoincompatible donors in mixed lymphocyte cultures or stimulated with phytohemagglutinin (PHA) to promote IL-2Ralpha expression. MJ, an HTLV-1-infected malignant T-cell line that overexpresses IL-2Ralpha, and the IL-2Ralpha-negative cell lines MOLT-4F and MT-1, were used as controls. INTERVENTIONS Bovine RNaseA was chemically conjugated to 7G7B6, a monoclonal antibody to the alpha-chain of human IL-2 receptors, and several concentrations of the conjugates were added to the lymphocyte cultures. MAIN OUTCOME MEASURES Inhibition of cell proliferation as a percentage of 3H-thymidine incorporation in 24 hours. RESULTS 7G7B6-RNaseA dose-dependently inhibited cell proliferation in PHA-stimulated human lymphocytes at a 50% inhibitory concentration (IC50) of 2 x 10(-7) M. whereas RNase alone and RNase plus antibody had no inhibitory effect. 7G7B6-RNaseA also dose-dependently inhibited the human mixed lymphocyte reaction at an IC50 of 2 x 10(-6) M, whereas RNase alone did not. The conjugate also inhibited cell proliferation in MJ cells, a cell line that is infected with HTLV-I and overexpresses the high-affinity IL-2 receptor, at an IC50 of 5 x 10(-7) M. However the conjugate had no inhibitory effect on the IL-2 receptor non-expressing human T-cell lymphoblastic leukaemia cell lines MOLT-4F or MT-1. CONCLUSION 7G7B6-RNaseA can inhibit cell proliferation in antigen- or mitogen-stimulated lymphocytes that overexpress high-affinity IL-2 receptors, and it may be safer than conventional chemotherapy or immunotoxins in the treatment of transplant rejection, certain lymphocytic malignancies, and other IL-2R-associated diseases, because it contains a mammalian cytotoxic enzyme.