Kana Saito

Lymphoepithelial Cyst of the Pancreas: Report of a Case

A lymphoepithelial cyst (LEC) is an extremely rare benign lesion of the pancreas. During a medical check-up, a 77-year-old man without any symptoms was found to have a cyst in the body of the pancreas. His serum carbohydrate antigen 19-9 level was slightly elevated. Computed tomography showed a multilocular, low-attenuating cyst on the superior surface of the pancreatic body. Thus, we performed distal pancreatectomy with splenectomy. Histological examination revealed that the cyst wall was lined with squamous epithelium and surrounded by abundant mature lymphoid tissue. Keratinous substances were present in the cyst. An LEC of the pancreas is associated with a good prognosis and, although unusual, it should be considered in the differential diagnosis of pancreatic cystic lesions. Minimal resection of the cyst should be performed whenever possible, and extensive surgery avoided. For patients with a high surgical risk, fine-needle aspiration biopsy may be considered.

Surgical Treatment for Esophageal Cancer

Esophageal cancer is one of the most difficult malignancies to cure. The prognosis remains unsatisfactory despite significant advances in surgical techniques and perioperative management. The optimal treatment strategy for localized esophageal cancer has not yet been established. Surgical resection remains the mainstay of treatment for esophageal cancer, and curative resection is the most important surgery. Extended esophagectomy with three-field lymphadenectomy provides the highest quality of tumor clearance and prolongation of patient survival. There has been intense effort in developing novel strategies to treat patients with resectable esophageal cancer. Various combined-modality approaches have been attempted to improve treatment outcomes. Definitive chemoradiotherapy has an impact on long-term survival in patients with resectable esophageal cancer. Accordingly, there are three main combined-modality approaches: esophagectomy with adjuvant chemotherapy or chemoradiotherapy; primary definitive chemoradiotherapy with or without salvage esophagectomy, and preoperative chemoradiotherapy followed by planned esophagectomy. Recently, owing to the remarkable advances in optical technology, minimally invasive esophagectomy using endoscopic instruments has been introduced into esophageal cancer surgery. This article reviews recent changes in the treatment of esophageal cancer surgery, and considers the role of esophagectomy.

Laparoscopic Appendectomy for Appendiceal Endometriosis Presenting as Acute Appendicitis: Report of a Case

Endometriosis is a relatively common disorder in women of reproductive age; however, appendiceal endometriosis is rare. Thus, a definitive diagnosis is likely to be established only by histology of the appendix. We report a case of endometriosis of the appendix in a 42-year-old woman who presented with symptoms of acute appendicitis. We treated the patient by performing laparoscopic appendectomy, which resulted in a good outcome.

Esophageal granular cell tumor covered by intramucosal squamous cell carcinoma: report of a case.

We report a case of a granular cell tumor (GCT) covered by squamous cell carcinoma (SCC) in the esophagus. A 69-year-old Japanese man was admitted to our hospital for treatment of superficial esophageal cancer detected by upper gastrointestinal endoscopy. Endoscopic examination revealed a shallow ulcer in the esophagus, 28–32 cm from the incisor teeth. The pathological findings of a biopsy of the lesion were moderately differentiated SCC. Thus, we performed partial esophagectomy with two-field (thoraco-abdominal) lymph node dissection. Microscopic examination of the surgical specimen revealed intraepithelial SCC with minimal invasion, and a GCT, 3 × 1 mm in size, in the submucosa just beneath the SCC. Cytoplasmic granules in the GCT were positive for periodic acid-Schiff. Immunohistochemically, the GCT was strongly positive for S-100 protein. To our knowledge, this is the first published report of a GCT covered by SCC in the esophagus.

Aberrant methylation status of known methylation- sensitive CpG islands in gastrointestinal stromal tumors without any correlation to the state of c-kit and PDGFRA gene mutations and their malignancy

To identify additional alterations to c‐kit or platelet‐derived growth factor receptor α (PDGFRA) genes in gastrointestinal stromal tumors (GIST), we investigated the methylation status of nine known methylation‐sensitive CpG islands (p15, p16, p73, 0‐6‐methylguanine‐DNA methyltransferase, E‐cadherin, mutL homolog 1, colon cancer nonpolyposis type 2 (escherichia), methylated in tumors [MINT]1, MINT2, and MINT31), and compared the results with the malignant potential and gain‐of‐function mutation types of GIST. Thirty‐five GIST (c‐kit mutations in 25 cases, PDGFRA mutations in seven cases, and lacking either mutation in three cases) were subjected to methylation‐specific polymerase chain reaction to detect the methylation status of the nine methylation‐sensitive CpG islands. Aberrant DNA methylation of these loci was found in 94% of all GIST. The rates of DNA methylation at each locus were as follows: hMLH1, 60%; MINT2, 51%; MGMT, 49%; p73, 49%; p16, 20%; E‐cadherin, 14%; MINT1, 9%; p15, 6%; and MINT31, 0%. CpG islands methylator phenotype, which was defined as methylation involving more than three gene promoters, was found in 57% of GIST with c‐kit or PDGFRA gene mutations. According to the risk categories, CpG islands methylator phenotype was present in 55% of low‐risk GIST, and in 58% of high‐risk GIST. Our results suggested that in addition to c‐kit or PDGFRA mutations, the aberrant methylation of CpG islands, especially of mismatch‐repair genes, may have a role in the tumorigenesis of GIST. (Cancer Sci 2008; 99: 253–259)

Comparative study using rabbit-derived polyclonal, mouse-derived monoclonal, and rabbit-derived monoclonal antibodies for KIT immunostaining in GIST and other tumors

To find a better condition for KIT immunostaining, five antibodies against KIT were compared, including a widely used polyclonal antibody (pAb) A4502, three mouse‐derived mAb (MMA; T595, 1DC3, K45), and a newly developed rabbit‐derived mAb (RabMA; Y145). Twenty‐three gastrointestinal stromal tumors (GIST) were stained, including five KIT‐weak or ‐negative GIST with PDGFRA gene mutations from a previous report, six Ewing/malignant primitive peripheral neuroectodermal tumor, six malignant melanomas, two neuroblastomas, six seminomas, seven thymic carcinoma and seven small cell carcinomas of the lung as KIT‐expressing tumors, and four leiomyomas, six leiomyosarcomas, five gastric schwannomas, four solitary fibrous tumors, one inflammatory fibroid polyp and six desmoid tumors as KIT‐non‐expressing tumors. The positive rates of RabMA Y145 in KIT‐expressing tumors were almost equal to pAb A4502, whereas those of three MMA had lower rates. MMA T595 was positive for mast cells, but negative for interstitial cells of Cajal and some GIST. None of the KIT‐non‐expressing tumors was positive for Y145, whereas some leiomyosarcomas and desmoid tumors were positive for A4502. At present, pAb A4502 or RabMA Y145 seems to be suitable for KIT immunostaining in formalin‐fixed paraffin‐embedded tumor specimens, especially in the differential diagnosis of GIST from other mesenchymal tumors.

Laparoscopy-Assisted Resection of Ileocecal Intussusception Caused by Ileal Pedunculated Lipoma

We report on a case of ileal lipoma that prolapsed into the ascending colon and was resected by laparoscopy-assisted surgery. A 31-year-old male Japanese patient was admitted to our hospital because of hematochezia and anemia. Colonoscopy revealed a pedunculated polyp arising from the ileum. The surface was covered with slightly edematous mucosa. Abdominal computed tomography showed a low-density mass in the ascending colon. A diagnosis of pedunculated ileal lipoma with intussusception was made, and laparoscopy-assisted surgery was performed. The intussusception was reducted by resection of the lipoma. The surgical specimen was a 40 × 30 × 25 mm round tumor with a long stalk 11 cm in length. Microscopic examination of the specimen revealed ileal lipoma. Laparoscopic surgery is recommended for benign tumors of the small intestine because it is minimally invasive.

Gastrointestinal stromal tumor of the lesser omentum in a young adult patient with a history of hepatoblastoma: Report of a case

A gastrointestinal stromal tumor (GIST) of the lesser omentum is extremely rare. This report presents a case of GIST of the lesser omentum in a 22-year-old man with a history of hepatoblastoma. Computed tomography showed an abdominal mass about 30 mm in diameter adjacent to the lesser wall of the stomach. A laparotomy showed a mass of about 27 × 24 × 20 mm in diameter originating from the lesser omentum but isolated from the stomach and the liver. Histopathology showed that the tumor was composed of spindle-shaped tumor cells with high cellularity. Immunohistochemically, the tumor was positive for KIT and CD34. An in-frame deletion was observed in the c-kit gene exon 11. Therefore, the tumor was diagnosed as a GIST originating from the lesser omentum.

Recurrent, Spontaneous Esophageal Ruptures Associated With Antiphospholipid Antibody Syndrome: Report of a Case

A 52-year-old man was admitted to our hospital with a spontaneous esophageal rupture (Boerhaave syndrome) and was successfully treated. Eight years after the first incident, he was readmitted with a recurrent rupture. Recurrence of Boerhaave syndrome is extremely rare, with only 7 cases reported in the English literature. During treatment, the patient was also diagnosed with antiphospholipid syndrome (APS). Although APS is known to cause a variety of symptoms due to vascular thrombosis, recurrence of Boerhaave syndrome, coincident with APS, has never been reported. The pathogenesis of Boerhaave syndrome has not been clearly determined. This report serves to increase awareness of the risk of APS, which results in an increased risk of spontaneous rupture of the esophagus.

Evaluation of Pharyngeal Function between No Bolus and Bolus Propofol Induced Sedation for Advanced Upper Endoscopy

This study aimed to assess pharyngeal function between no bolus and bolus propofol induced sedation during gastric endoscopic submucosal dissection. A retrospective study was conducted involving consecutive gastric cancer patients. Patients in the no bolus group received a 3 mg/kg/h maintenance dose of propofol after the initiation of sedation without bolus injection. All patients in the bolus group received the same maintenance dose of propofol with bolus 0.5 mg/kg propofol injection. Pharyngeal functions were evaluated endoscopically for the first 5 min following the initial administration of propofol. Fourteen patients received no bolus propofol induction and 13 received bolus propofol induction. Motionless vocal cords were observed in 2 patients (14%) in the no bolus group and 3 (23%) in the bolus group. Trachea cartilage was not observed in the no bolus group but was apparent in 6 patients (46%) in the bolus group (P < 0.01). Scope stimulated pharyngeal reflex was observed in 11 patients (79%) in the no bolus group and in 3 (23%) in the bolus group (P < 0.01). Propofol induced sedation without bolus administration preserves pharyngeal function and may constitute a safer sedation method than with bolus.