Kazumitsu Koito

Solitary cystic tumor of the pancreas: EUS-pathologic correlation

BACKGROUND It is clinically important to distinguish neoplastic from non-neoplastic pancreatic cysts. METHODS Retrospective correlations were made between pathologic and EUS data from 52 pancreatic solitary cystic tumors: mucinous cystadenoma (10), mucinous cystadenocarcinoma (7), serous cystadenoma (5), ductectatic mucinous cystic tumor (10), solid and papillary epithelial neoplasm (5), and non-neoplastic cyst (15). The mean tumor size was 3.5 cm (range, 1.2 cm to 6.0 cm). RESULTS Six classifications of the internal structures of these cysts were developed: thick wall type, tumor protruding type, thick septal type, microcystic type, thin septal type, and simple type. Although all neoplastic cysts belonged to the first four types, all non-neoplastic cysts belonged to the last two types. The accuracy of EUS for differentiating tumors was estimated at 96% and 92%, respectively, by two observers. CONCLUSIONS EUS may become a mandatory modality for differentiating pancreatic solitary cystic tumors and choosing an optimal treatment.

High-dose-rate versus low-dose-rate intracavitary therapy for carcinoma of the uterine cervix: a randomized trial.

This was a prospective randomized clinical trial undertaken at our institution to compare low‐dose‐rate (LDR) intracavitary radiation therapy versus high‐dose‐rate (HDR) intracavitary radiation therapy for the treatment of cervical carcinoma.

Prognostic factors of nasopharynx tumors investigated by MR imaging and the value of MR imaging in the newly published TNM staging

PURPOSE To examine the usefulness of MR imaging for predicting local control of nasopharyngeal carcinoma (NPC) and the value of MR imaging in the newly published fifth edition of the TNM classification. METHODS AND MATERIALS We studied 29 patients with NPC with MR imaging and CT before and after treatment. Staging was done according to the fourth and newly published fifth editions of the International Union Against Cancer (UICC) staging system. The radiotherapy protocol was designed to deliver 66 to 68 Gy to the primary tumor and clinically involved nodes. RESULTS MR proved better than CT at identifying obliteration of the pharyngobasilar fascia, invasion of the sinus of Morgagni, through which the cartilaginous portion of the eustachian tube and the levator veli palatini muscle pass, invasion of the skull base, and metastases to lymph nodes in the carotid and retropharyngeal spaces. All seven patients without invasion of the pharyngobasilar fascia had local control. The local control rates of patients with invasion of the skull base were not good (60 to 73%). There was no apparent relationship between tumor volume determined by T1-weighted MR images and local control when the tumor volume was more than 20 cc. The newly published N staging system appears to successfully identify the high-risk group for distant metastasis as N3. In our series, four of five patients with N3 disease developed distant metastases. CONCLUSION Deep infiltration of the tumor is a more important prognostic factor in NPC than tumor volume. Since the newly published T staging system requires a search for tumor invasion into soft tissue such as parapharyngeal space and bony structures, MR imaging may be indispensable for the newly published NPC staging system.

Congenital Arteriovenous Malformation of the Pancreas : Its Diagnostic Features on Images

To analyze diagnostic features on images of congenital arteriovenous malformation (AVM) of the pancreas, we analyzed the diagnostic findings in six patients with the disease, using gray-scale ultrasonography (US), color Doppler US, computed tomography, and angiography and analyzed previously reported cases. AVM characteristic findings on images were multiple, small hypoechoic nodules on US, mosaic appearance of the lesion and pulsatile wave form in the portal vein on color Doppler US, conglomerated small nodular enhancement of the lesion and early appearance of the portal vein on CT, and a racemose network and early appearance of the portal vein on angiography. Five of the six patients underwent surgery, and all resected specimens were histologically found to be AVMs of the pancreas; however, one with developed portal hypertension at surgery died of repeated bleeding from esophageal varices. From analysis of total of 35 cases including our six cases, a mosaic appearance of the lesion was found in 100% and a pulsatile wave form in the portal vein in 77.8% on color Doppler US. Color Doppler US is noninvasive and useful for detecting congenital AVM of the pancreas at an early stage, preventing the portal hypertension causing esophageal varices and their rupture.

Efficacy of SPIO-MR imaging in the diagnosis of liver metastases from colorectal carcinomas.

Aim: To determine whether superparamagnetic iron oxide-enhanced magnetic resonance imaging (SPIO-MRI) could replace intravenous contrast-enhanced spiral CT (iv-CT) and spiral CT during arterial portography (CTAP) combined with spiral CT hepatic angiography (CTHA) in the diagnosis of liver metastases from colorectal carcinomas. Methods: Twenty-six adult patients with liver metastases were studied preoperatively by means of iv-CT, CTAP/CTHA, and SPIO-MRI. Preoperative diagnoses using iv-CT, CTAP/CTHA, and SPIO-MRI were compared with intraoperative and pathological findings in resected specimens. The gold standard for the lesions that were resected was histological examination. Intraoperative findings represented the gold standard for lesions that were not resected. Results: Twenty-six patients were found to have a total number of 43 liver metastases. The sensitivities of iv-CT, CTAP/CTHA, and SPIO-MRI were 74.4, 100, and 90.7%, respectively. SPIO-MRI was significantly superior to iv-CT (p < 0.05). The positive predictive values of iv-CT, CTAP/CTHA, and SPIO-MRI were 97.0, 91.5, and 100%, respectively. CTAP/CTHA yielded four false-positive lesions. In contrast, we detected no false-positive findings using SPIO-MRI. Conclusions: These results suggest that SPIO-MRI might not completely replace CTAP/CTHA, but could replace iv-CT in the diagnosis of liver metastases from colorectal carcinomas. It is thought that SPIO-MRI is a promising imaging modality for diagnosing liver metastases in patients with colorectal carcinoma because of its relatively high sensitivity and extremely high specificity.

General Pattern of Lymph Node Metastasis in Early Gastric Carcinoma

Abstract. A reliable method for recognizing lymph node metastasis is indispensable for the attending physician to recommend less extensive treatment for early gastric carcinoma. Here we review 1137 consecutive patients with a single primary lesion, and the incidence and distribution of nodal involvement were investigated for correlations with pathologic findings. The overall incidence of metastasis was 9.5%: 2.6% for mucosal and 16.5% for submucosal carcinomas, a significant difference. The occurrence of metastasis was highest for lesions of the macroscopically mixed type, microscopically diffuse type, and large size. The involved nodes were most frequently found in the perigastric nodes along the lesser and greater curvatures, and it was well correlated with the tumor location, macroscopically depressed/mixed type, cancer depth, and histology. The diffuse-type carcinomas were most likely to metastasize to distant nodes. The distribution of involved nodes for early gastric carcinoma was similar to that for advanced carcinoma, as previously been reported. The submucosal carcinomas in this series had no indications for less extensive treatment, such as endoscopic or laparoscopic limited surgery. These carcinomas should be subject to standard surgery with gastrectomy and combined dissection of lymph nodes, especially node stations 1 and 3 to 8. The mucosal carcinomas sometimes involved the perigastric nodes, and such cases underwent gastrectomy and lymphadenectomy of node stations 1 and 3 to 7. Mucosal carcinomas 10 mm or less in size were negative for lymph node metastasis and were considered appropriate for less extensive treatment.

Renal Artery Aneurysm: Evaluation with Color Doppler Ultrasonography Before and After Percutaneous Transarterial Embolization

Renal artery aneurysms account for 22% of all visceral aneurysms.1 The prevalence of renal artery aneurysms in the general population is reported to vary between 0.01% and 1.0%2; however, this prevalence has recently increased because of the greater detection of these aneurysms made possible by advances in ultrasonography, CT, and MR imaging. The most serious complication of renal artery aneurysms is their rupture, which is followed by sudden death.3 The likelihood of rupture seems to increase as the diameter of the aneurysm exceeds 1 cm.2,3 Although surgical treatment had been common for these aneurysms (i.e., total renal resection), a percutaneous embolization technique has also recently been performed with success.4 This technique is less invasive than surgical resection for patients with renal artery aneurysms and sometimes preserves renal function. We report a case of a renal artery aneurysm 4 cm in diameter treated with percutaneous transcatheter embolization whose therapeutic effect was better evaluated by color Doppler ultrasonography than CT and MR imaging.

Assessing the Suitability of Gastric Carcinoma for Limited Resection: Endoscopic Prediction of Lymph Node Metastases

Abstract. Some early gastric carcinomas are free of lymph node involvement; however, the pathosis of these carcinomas is neither well understood nor reflected in the choice of less extensive treatment. We investigated the relation of nodal involvement to pathologic findings of the resected specimens. We present promising standards for predicting the nodal status of early gastric carcinomas, contributing to the indication for limited surgery. The relation of lymph node metastasis to tumor size, infiltration depth, macroscopic appearance, and histologic type of early gastric carcinomas were investigated in 1470 patients with a single primary early gastric carcinoma. Of these carcinomas, 763 were limited to the mucosa (mucosal carcinoma) and 707 to the submucosa (submucosal carcinoma). The overall incidence of lymph node metastasis was 9.0%:2.1% in mucosal carcinomas and 16.5% in submucosal ones, with a significant (p < 0.001) difference of nodal involvement between the two. The macroscopically elevated or compound-type carcinomas 10 mm or less in diameter were all node-negative, whereas some depressed-type carcinomas were node-positive. The incidence of undifferentiated carcinomas increased with tumor diameter, irrespective of whether they were mucosal or submucosal carcinomas, and they were significantly more node-positive than were differentiated carcinomas: p< 0.001 for mucosal carcinomas and p < 0.05 for submucosal ones. The carcinomas satisfying the following criteria are node-negative and eligible for limited surgery: (1) mucosal carcinoma; (2) elevated lesion <10 mm in diameter; (3) differentiated adenocarcinoma; and (4) no ulcer or ulcer scar. The other carcinomas are potentially node-positive and standard surgery is recommended.

HIGH-DOSE-RATE INTRACAVITARY BRACHYTHERAPY: RESULTS OF ANALYSES OF LATE RECTAL COMPLICATIONS

PURPOSE To examine the incidence of radiation-induced late rectal complications by analyzing the data of measured rectal doses in patients with cancer of the uterine cervix treated with high-dose-rate intracavitary brachytherapy. METHODS AND MATERIALS We measured doses to the rectum in 105 patients with cancer of the cervix during high-dose-rate intracavitary brachytherapy with a semiconductor dosimeter that can measure five points in the rectum simultaneously. On the basis of these measurements, equivalent doses, to which the biologically equivalent doses were converted as if given as fractionated irradiation at 2 Gy/fraction, were calculated as components of the cumulative dose at five rectal points in intracavitary brachytherapy combined with the external whole pelvic dose. RESULTS The calculated values of equivalent doses for late effects at the rectum ranged from 15 to 100 Gy (median 60 Gy for patients who did not develop complications and 76 Gy for patients who subsequently developed Grade II or III complications). When converted to a graph of absolute rectal complication probability, the data could be fitted to a sigmoid curve. The data showed a very definite dose-response relationship, with a threshold for complications at approximately 50 Gy and the curve starting to rise more steeply at approximately 60 Gy. The steepest part of the curve had a slope equivalent to approximately 4% incidence/1 Gy increase in equivalent doses. CONCLUSION The radiation tolerance dose, 5% and 50% complication probability, was about 64 and 79 Gy, respectively. Our data almost agree with the prescribed dose for the rectum for the radiation tolerance doses on the basis of the recorded human and animal data. The probability of rectal complications increased drastically after the maximal rectal dose was >60 Gy.

Macrocystic serous cystadenoma of the pancreas : importance of co-existent tiny cysts depicted by EUS

Abstract: The case of a 38-year-old man with an unusual type of serous cystadenoma of the pancreas is reported. A multilocular cystic tumor in the head of the pancreas was detected on abdominal ultrasonography and computed tomography. On endoscopic ultrasonography, the major cysts ranged from 2.0 to 4.5 cm in size. In addition to these large cysts, a few small cysts were detected. Based on these findings, this tumor was diagnosed as a macrocystic type serous cystadenoma. Because endoscopic retrograde pancreatogram showed a compression of the main pancreatic duct around the tumor, and because the size of the tumor had been increasing over a 3-year period, surgical intervention was performed. The resected tumor consisted of macrocysts, with a few small cysts, and was histologically diagnosed as serous cystadenoma. Endoscopic ultrasonography appears to provide an excellent inside image of this unusual tumor, and because of its ability to detect small cystic lesions clearly, it could be useful in the diagnosis of macrocystic serous cystadenoma.