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We report the first case of appendiceal mucinous cystadenoma associated with the kidney. A 57-year-old man with chronic renal failure presented with a right renal mass. During laparoscopic nephrectomy, frozen analysis of a tubular structure extending from the mass showed appendiceal tissue. The mass, appendix, and what was believed to be the right kidney were removed. Pathologic examination demonstrated mucinous cystadenoma of the appendix. No renal tissue was identified, but the patient refused further treatment. This case demonstrates that mucinous cystadenomas arising from retroperitoneal structures might mimic renal neoplasms and should be considered in the differential diagnosis of cystic renal masses.

Appendiceal mucoceles are a group of lesions in which the appendiceal lumen becomes distended with mucus. They may be associated with an unusual form of gelatinous ascites termed pseudomyxoma peritonei. We report herein a 77-year-old male patient with appendiceal mucinous cystadenocarcinoma and pseudomyxoma peritonei, whose initial symptoms were abdominal pain and distension and intestinal obstruction. He had a history of explorative laparotomy for an abdominal mass and ascites 14 months ago at another center. He was suffering from abdominal pain and intestinal obstruction on admission to the emergency service. We performed right colectomy and total resection of the mass which originated from the appendix. Pathologic examination of the specimen showed low-grade mucinous cystadenocarcinoma and pseudomyxoma peritonei. The postoperative period was uneventful.

Background: Primary appendicular adenocarcinoma is a rare type of appendicular carcinoma. We report mucinous appendicular adenocarcinoma during pregnancy. To our knowledge, this is the third reported case., Case: A 35-year-old woman at 21 weeks of gestation presented with acute abdominal symptoms for the previous 10 days and underwent appendectomy. Histopathologically, examination of the appendectomy material was reported as "mucinous appendicular cystadenocarcinoma." The pregnancy was terminated by misoprostol induction. A right hemicolectomy and staging procedure were performed on the third postpartum day with relaparotomy., Conclusion: Although it rarely coexists with pregnancy, primary appendicular adenocarcinoma should be considered in pregnant women with atypical acute abdominal symptoms of long duration. Primary adenocarcinoma of the appendix should be treated with right hemicolectomy even if it is a secondary procedure. Termination of pregnancy is not essential to the surgical procedure, and the decision on the outcome of the pregnancy should be made with the patient.

Although acute appendicitis is the most common disease of the appendix, the appendix can be involved by a wide range of diseases. Diseases other than acute appendicitis may produce signs and symptoms indistinguishable from those of acute appendicitis. Computed tomography (CT) can provide important information for diagnosis and evaluation of appendiceal diseases. The various CT and histologic features of appendiceal benign and neoplastic diseases are discussed, illustrated, and correlated in this article. Radiologists need to understand the full spectrum of appendiceal abnormalities, their underlying pathologic changes, and associated CT imaging findings.

Carcinoid tumours of the appendix are rare tumours of the bowel which occasionally are found histologically in resected appendices. There are no publications on the sonographic diagnosis of carcinoid tumours of the appendix in children. We report on the sonographic examination of a carcinoid tumour in a 14-year-old boy. Sonography showed a hypoechoic tumour located at the apex of the appendix with eccentric growth. Histology revealed a carcinoid tumour with invasion of the regional lymphatic vessels.

Adenocarcinoid of the appendix is a rare tumor with the histological features of both adenocarcinoma and carcinoid tumor. However, its biological behavior and malignant potential are still unclear. We treated two patients with this unusual tumor; a 60-year-old man and a 79-year-old woman. Both patients were initially diagnosed with acute appendicitis followed by an appendectomy. At surgery, the appendix was seen to be acutely inflamed without any macroscopic signs of tumor. Postoperative histological analysis revealed an adenocarcinoid tumor in the appendix, which had spread diffusely into its wall without forming a mass. Immunohistochemical staining with p53, MIB-1, bcl-2, and carcinoembryonic antigen suggested that neither of these tumors were particularly aggressive. Adenocarcinoid of the appendix is a rare tumor, which is very difficult to diagnose preoperatively and even macroscopically, making histological examination essential.

Appendiceal adenocarcinoma is a rare malignancy for which there is no characteristic clinical presentation. We describe five women who presented with signs and symptoms characteristic of advanced ovarian cancer but whose final diagnosis was stage IV appendiceal cancer. Between 1998 and 1999, five women treated for presumed ovarian cancer were identified as having primary appendiceal cancer. Medical records and pathology were retrospectively reviewed. The median age was 47 years (range 36-61 years). All had elevated preoperative CA125 levels with a median value of 171 micro/ml (range 46-383). Four women underwent right hemicolectomy with two requiring radical surgical tumor debulking to render them optimally debulked. Four had postoperative chemotherapy, the most common agent used was 5-flourouracil. Median survival was 6.75 months (range 19 days-11 months). Primary adenocarcinoma of the appendix is rare; therefore, the clinical utility of radical tumor debulking and chemotherapy is not well described. Given the poor survival in our series, all efforts should be considered palliative. Although this disease process is uncommon, it should be entertained by gynecologic oncologists in the differential diagnosis of an intra-abdominal mass and ascites. The ability to make the correct diagnosis and differentiate between an ovarian and appendiceal primary is critical as the treatment modalities vary.

Purpose: To evaluate the computed tomographic (CT) findings in patients with acute appendicitis related to an underlying appendiceal neoplasm., Materials and Methods: Clinical and pathologic data obtained over a 10-year period in 65 patients with primary appendiceal neoplasms were reviewed. Preoperative CT studies in patients who presented clinically with symptoms of acute appendicitis were analyzed retrospectively and in consensus by three radiologists. The appendix was evaluated on CT scans for morphology, location, presence of calcification, maximal diameter, and wall thickness., Results: Twenty-six (40%) of the 65 patients with appendiceal neoplasms had presented with symptoms of acute appendicitis. Preoperative CT studies available in 22 patients showed increased appendiceal diameter, wall thickening, and periappendiceal fat stranding in 22 (100%), 22 (100%), and 21 (95%) patients, respectively. The appendiceal diameter was greater than 15 mm (mean diameter, 2.9 cm) in 19 patients (86%). Morphologic changes of concern for neoplasm were present in 19 patients (86%) and included cystic dilatation in nine patients and presence of a soft-tissue mass without dilatation in 10 patients. An appendiceal diameter greater than 15 mm and/or a morphologic abnormality were present in 21 of 22 cases (95%)., Conclusion: CT findings strongly suggest the presence of underlying neoplasm in the majority of patients with secondary appendicitis.

Bone metastases are assumed to be rare in carcinoid disease and to be associated mainly with bronchial primaries. The aim of the present study was to evaluate the occurrence of bone metastases in patients with metastatic carcinoid tumours, and the role of various nuclear medicine modalities (bone scintigraphy, (111)In-pentetreotide and (131)I-MIBG) in its detection and clinical management. Nine (2 women, 7 men, median age 65 years) out of 86 consecutive carcinoid patients treated between 1987 and 1998 developed bone metastases (10%) with a median interval of 37 months between the diagnosis of metastatic carcinoid and bone metastases. Seven of them had non-bronchial primaries. (111)In-pentetreotide scintigraphy failed to detect the bone lesions in 50% of the cases, and (131)I-meta-iodobenzylguanidine(MIBG) scintigraphy in almost 80% of cases. Standard bone scintigraphy, however, was positive in all. Pain relief of bone metastases by means of radiation therapy was obtained in 5 of 6 patients. In another patient palliation of pain symptoms was obtained with Rhenium-186-hydroxyethylidene diphosphonate. Octreotide, Interferon of MIBG were ineffective for this purpose. It is concluded that bone metastases in carcinoid patients may be missed on (131)I-MIBG and (111)In-pentetreotide scintigraphy. Bone scintigraphy is a sensitive imaging technique. Diagnostic nuclear medicine modalities may be helpful in the clinical management of carcinoid disease.

Objective: The purpose of this report is to describe the clinical, CT, and pathologic features of non-Hodgkin's lymphoma of the vermiform appendix., Conclusion: Non-Hodgkin's lymphoma of the appendix typically manifests with acute symptoms in patients who have no prior history of lymphoma. Most patients with the disease present clinically with signs and symptoms suggestive of acute appendicitis. On CT, lymphomatous infiltration of the appendix produces markedly diffuse mural soft-tissue thickening (range of diameters, 2.5-4.0 cm; mean diameter, 3.2 cm). The vermiform morphology of the appendix is usually maintained, and aneurysmal dilatation of the lumen is sometimes seen. Stranding of the periappendiceal fat seen on CT may represent superimposed inflammation or even direct lymphomatous extension. Coexisting abdominal lymphadenopathy is not seen in all patients. Although appendiceal lymphoma is rare, the characteristic CT appearance could lead to a preoperative diagnosis.

We present a case of the diagnosis of an appendiceal mucocele in a 23-year-old woman. The unusual preoperative sonographic appearance of the lesion is described and its clinical significance and differential diagnosis are discussed.

Primary adenocarcinoma of the appendix is rare, especially the colonic type. We report a case of appendiceal adenocarcinoma of colonic type associated with perforating peritonitis after aorto-femoral artery bypass surgery. A 79-year-old woman presented with fever and pain in the right lower abdomen. She had undergone aorto-femoral artery bypass surgery due to arteriosclerosis obliterans 6 months earlier. Abdominal ultrasonography and computed tomography showed a suspected pool of fluid surrounding the artificial vessel and a mass lesion in the upper end of the fluid collection. These findings suggested localized peritonitis due to appendiceal perforation. Emergency laparotomy showed a pool of pus around the artificial vessel and inflamed appendix, which adhered to the surrounding tissue. The mass was excised in combination with an ileocaecal resection, followed by an ileocolic anastomosis. The histological diagnosis was moderately differentiated adenocarcinoma of the appendix, colonic type. The tumour had infiltrated and obstructed the lumen of the orifice of the appendix, which may have caused perforation of the appendix. She was examined at regular periodic follow-ups and no evidence of recurrence or metastasis was noted in the 12-month postoperative period. These findings indicate that, in cases of acute appendicitis, especially with perforation, the possibility of appendiceal adenocarcinoma should be considered.

Objective: To develop a collaborative approach for the treatment of gastrointestinal carcinoid tumours and carcinoid syndrome., Participants: Leaders in the medical, endocrine, radiologic and surgical treatment of carcinoid disease were selected to present papers at the Carcinoid Syndrome Symposium on Treatment Modalities for Gastrointestinal Carcinoid Tumours and participate in the workshop that followed., Evidence: A multidisciplinary symposium with experts in the field of carcinoid syndrome was organized at the University of Calgary. Data presented, participation of the attendees and a review of the literature were used in the workshop to develop a collaborative approach to the management of carcinoid tumours., Benefits: Carcinoid tumours are rare and few centres have large experiences in their treatment. Before the development of this collaboration, patients with carcinoid tumours received a unidisciplinary approach depending on referral patterns. The development of a multidisciplinary neuroendocrine clinic helped to unify the approach to these patients, yet a consensus on the treatment of carcinoid tumours was lacking. The expertise at the symposium allowed for consensus and the development of treatment algorithms, including biochemical screening, radiographic localization and surgical intervention, for gastrointestinal carcinoid tumours. The role of medical and hormonal therapy after cytoreducion is presented., Recommendation: Patients with carcinoid tumours require a multidisciplinary approach to their care.

Intussusception of the appendix vermiformis in adults is an unusual entity. We present a 52-year-old male patient with intussusception of the appendix due to a mucinous cystadenoma, and discuss the clinical features, preoperative diagnosis, classification and therapy of this condition together with a review of the literature., (Copyright 2002 S. Karger AG, Basel)

A case of primary adenocarcinoma in appendiceal diverticulosis is reported. Such a case has never been mentioned before in the literature. It was not possible to diagnose the case preoperatively. This emphasizes the importance of histological examination of all appendiceal samples.

Background: To present the computed tomographic (CT) findings of synchronous mucinous tumors of the ovary and the appendix associated with pseudomyxoma peritonei (PMP)., Methods: Imaging studies, mainly abdominal CT scans, of three women aged 49-75 years were reviewed. Attention was directed to the ovarian masses, peritoneal seeding, and the presence of an appendiceal mucocele., Results: The ovarian tumors and the appendiceal mucocele were clearly demonstrated in two cases, and they were part of the extensive PMP in the third patient. Ascites was found in all cases, with internal septation in one. Associated scalloping of the liver margins and hypodense peritoneal implants, with extensive bowel involvement, were seen in another one. Pathologically, there was one case of right ovarian mucinous cystadenoma and villous adenoma of the appendix, one case of right ovarian and appendiceal mucinous cystadenocarcinoma, and one case of bilateral metastatic ovarian implants of appendiceal mucinous cystadenocarcinoma. PMP was found in all. In the case with benign tumors of the ovary and the appendix, the PMP was classified as a benign mucinous spillage. This patient returned 33 months after surgery with PMP, in which epithelial cells were found., Conclusions: Radiologists should be familiar with the clinical occurrence of synchronous mucinous tumors of the ovary and the appendix associated with PMP and with the typical CT findings of the latter two entities. Alternatively, when the imaging findings suggest ovarian cystic tumor with PMP, the radiologist should be alerted to the probability of a clinically unsuspected appendiceal mucocele and should search for it.

Objective: The preoperative diagnosis of a primary appendiceal tumor can be difficult because of its rarity and the paucity of material in the radiology literature. The purpose of this study was to describe CT findings in six patients with primary mucinous cystadenocarcinoma of the appendix., Conclusion: When CT reveals a cystic mass with enhancing wall nodularity in the expected area of the appendix, especially in older patients, the possibility of primary mucinous cystadenocarcinoma should be considered.

Aim: The aim of the study was to assess the value of sonography in detecting the normal appendix and in identifying abnormality., Methods: The appendiceal wall thickness (normal: <3 mm) and ultraluminal contents (abnormal: large appendicolith, non-expressible fluid) were used as the primary criteria to determine the appendiceal status in 716 appendices. In patients who underwent appendicectomy (n = 166), surgical and histopathological findings were correlated with the ultrasound (US) findings; in patients who did not have surgery the reference standard was the clinical consensus based on follow-up., Results: Thirty-four patients out of 179 with abnormal sonographic findings did not undergo appendicectomy and recovered spontaneously; in 22 of these, the US changes were confined to the appendiceal tip. A normal appendix was identified in 537 patients (45.9% of all patients without appendicitis), with histologic verification subsequently obtained in 21. In 76 normal appendices (14.2% out of all normal appendices), luminal dilatation due to non-expressible inspissated faeces resulted in appendiceal outer diameter >6 mm (range, 6.2-12 mm); a histopathologic proof of non-inflamed appendix was obtained in seven of these., Conclusions: A normal appendix can be visualized in a high percentage of cases and it may present with an outer diameter >6 mm (the widely-accepted upper limit of normal) due to the inspissated faecal material within the lumen. A significant percentage of early appendicitis can resolve spontaneously, especially when confined to the appendiceal tip.

Pseudomyxoma peritonei is a rare disease in which the abdominal cavity fills with thick mucoid material secondary to either benign or malignant conditions. We discuss a case where pseudomyxoma peritonei secondary to adenocarcinoma of the appendix was diagnosed and managed laparoscopically. The laparoscopic approach allows thorough exploration of the abdomen, as well as irrigation and aspiration of the thick mucinous material using a 10-mm suction cannula and the instillation of mucolytic agents such as 5% dextrose solution. Appendectomy or right hemicolectomy can be performed with minimal disturbance of the anterior abdominal wall, thus minimizing future adhesions as well as possible tumor-cell implantation. Intraperitoneal catheters for chemotherapy can be placed easily through the port sites. These measures offer an alternative to radical peritoneal dissection and can be accomplished during the initial laparoscopic exploration.

A 63-year old female patient was admitted with a unclear abdominal ultrasound scan. Despite all our diagnostic examinations, the diagnosis--mucinous cystadenoma--was first established during surgery by intraoperative histological evaluation. We discuss the diagnostic possibilities and therapeutic approach.

Mucinous cystadenoma is a rare tumour of the vermiform appendix and is associated with cystic dilatation of the appendix, to which the more general term of mucocoele has been applied. Mucocoele of the appendix is only a descriptive term for abnormal mucus accumulation causing distension of the appendiceal lumen, irrespective of the underlying cause. Pre-operative diagnosis of appendix mucocoele, though infrequently made, is important as some of these lesions may be malignant, and also is essential in order to avoid the risk of rupture at surgery with subsequent development of pseudomyxoma peritonei. The appearances of mucocoele of the appendix and its uncommon variant of myxoglobulosis on plain radiograph, ultrasound and barium study are presented, together with review of the literature.

Malignant appendix tumours are rare entities. Especially adenocarcinomas, which only appear in about 10% of appendix tumours, are very seldom. Preoperative diagnosis is very difficult due to a lack of typical clinical signs and a clinical appearance mimicking perforated appendicitis. Nevertheless, sonography is able to show indirect signs and therefore it can provide the surgeon with more information for a better operative treatment.

Purpose: Somatostatin receptor scintigraphy is used to diagnose carcinoid of the gastrointestinal tract. Its sensitivity ranges from approximately 75%-100%. Therefore, it was hypothesized that it can be used in the postsurgical follow-up to detect residual carcinoid, recurrence, and metastatic disease., Results: This article is concerned with the findings of somatostatin receptor imaging performed on a 12-year-old girl 8 weeks after appendectomy. Histologic examination showed an incidental appendix carcinoid. Somatostatin receptor scintigraphy performed for detection of lymph node metastatic spread of the carcinoid showed focal tracer accumulation at the former operative site; subsequently, a right hemicolectomy was performed. However, histologic examination of the surgical tissue showed no evidence for carcinoid., Conclusion: It is concluded that there are some potential pitfalls for somatostatin receptor imaging at least soon after surgery. Therefore, it should not be used to aid in reoperation.

Villous adenoma of the vermiform appendix is very rare; the treatment of choice is appendectomy. We report a 72-year-old woman with a villous adenoma and a single focus of invasive, colonic adenocarcinoma. This finding required changes in diagnostic procedures and treatment, and altered the prognosis. The purpose of this report is to increase awareness of this phenomenon and to indicate correct management.

A case of mucinous carcinoid of the appendix presenting as bilateral Krukenberg tumors is reported. The patient, a 66-year-old woman, presented with vaginal spotting and lower abdominal pain of 2 months' duration. Sonography revealed a 5-cm ovarian mass. At operation a frozen section revealed metastatic mucinous carcinoid of the left ovary. Twenty months after radical surgery the patient died from abdominal carcinomatosis despite 4,500 cGy of abdominal radiation and multiagent chemotherapy. Primary ovarian carcinoid is invariably unilateral, whereas metastatic carcinoid to the ovary is almost always bilateral. The mucinous subtype appears to be more aggressive whether primary or metastatic.

Background: Cytoreductive surgery and intraperitoneal chemotherapy have been used to treat peritoneal carcinomatosis. A complete surgical resection is required for optimal results to be achieved. This study evaluated the preoperative computed tomographic (CT) findings in patients with mucinous peritoneal carcinomatosis in order to predict the probability of a complete resection., Study Design: Computed tomographic scans of the abdomen and pelvis were reviewed retrospectively in 45 patients with a diagnosis of mucinous peritoneal carcinomatosis who were treated with surgery and intraperitoneal chemotherapy. According to the completeness of cytoreduction, patients were divided into two groups. Patients in the first group (n = 25) had complete cytoreduction (CR) with no tumor deposits 2.5 mm in diameter or larger left behind. The surgical resection of tumor was incomplete in the second group of patients (n = 20). Sixteen CT parameters were initially examined in each group of patients and statistically evaluated according to the completeness of the cytoreductive surgical procedure., Results: The incidences of six CT findings were significantly different in the two groups of patients. These findings were: tumor volume in small bowel mesentery (p < 0.001), tumor volume in proximal jejunum (p = 0.003), tumor volume in distal jejunum (p = 0.002), tumor volume in proximal ileum (p = 0.003), mesentery configuration (p < 0.001), and obstruction of bowel segments by tumor (p < 0.001). A statistical approach using a tree-structured diagram showed that patients with both obstruction of bowel segments by tumor and tumor diameter greater than 0.5 cm on small bowel surfaces exclusive of distal ileum on preoperative CT scan, had an 88 percent probability of incomplete resection. Patients without these two CT findings had a 92 percent probability of complete resection., Conclusions: This study shows that selection criteria for patients with mucinous peritoneal carcinomatosis are available on a preoperative CT scan of the abdomen and pelvis. Patients whose scans show obstruction of bowel segments by tumor and tumor diameter greater than 0.5 cm on small bowel surfaces exclusive of distal ileum are unlikely to be candidates for cytoreductive surgery for the treatment of peritoneal carcinomatosis.

A case of an appendiceal cystadenoma resulting in a large mucocele in a 35 year old man presenting with abdominal pain is reported. On ultrasonography, an unusual appearance of strand-like layers of varying echo-texture suggesting a solid lesion was seen. On computed tomography, calcification and contrast enhancement of the rim was noted. The spectrum of imaging appearances of appendix mucoceles is reviewed.

Appendiceal mucoceles (AM) are rare lesions of the appendix, characterized by an accumulation of mucus. Two main pathogenic mechanisms may be invoked to explain their development. Firstly, AM are secondary to an obstruction of the appendiceal lumen for a wide variety of reasons. Secondly, they may be due to tumours of the appendix, whether malignant (cystadenocarcinomas) or benign (cystadenomas), responsible for a hypersecretion of mucus. Intraperitoneal mucinous effusion (IME) develops when appendiceal perforation occurs, especially with malignant AM. We found 13 retention AM and in most a definite obstructive lesion was present. There were 3 malignant AM, all associated with a neoplastic IME. While they are frequently described in the literature, no cystadenoma was observed in these series. Clinical symptoms are often confusing, but paraclinical investigations may lead to preoperative diagnosis. Appendectomy is the treatment of retention AM and cystadenoma. Their prognosis is related to other associated diseases, namely ovarian and colorectal tumours, but is otherwise good. Cystadenocarcinomas require a right hemicolectomy with evacuation of IME but their prognosis is poor.

Adenocarcinoid (mucinous carcinoid or goblet cell carcinoid) is an unusual tumour of the appendix with histologic and prognostic features between those of carcinoid and adenocarcinoma. Most patients with adenocarcinoid tumours of the appendix present with symptoms consistent with those of acute appendicitis. We describe a 31 year-old male who presented with such symptoms. Ultrasonography demonstrated an acutely inflamed appendix with a hypoechoic area in the midportion of the appendix, suspicious of a tumour. This rare type of tumour is briefly presented.

A previously healthy man had a carcinoid tumor that caused obstruction and dilatation of the appendiceal lumen, with subsequent inflammation of the appendix. He had acute pain in the lower right abdomen, loss of appetite, constipation, pyrexia, and an increased erythrocyte sedimentation rate without leukocytosis. Although his clinical signs and symptoms subsided, the persistent pathologic finding of a large dilated appendix at examination with ultrasound warranted surgery, which, with microscopy, established the correct diagnosis.

Preoperative administration of radiolabeled monoclonal antibody allows radioimmunoguided surgery with hand-held intraoperative detection devices. From a theoretical perspective, this technology may offer more knowledgable patient management and more complete resection of intra-abdominal cancer. False-positive examinations may seriously jeopardize the widespread application of this apparatus. Our experience with a patient with false-positive lymph nodes following administration of 125I-labeled B72.3 monoclonal antibody is reported. After careful histopathological analysis of five nodes thought to be false-positive for cystadenocarcinoma, one lymph node was found to have a minute nidus of cancer. The cause of false-positive radioimmunoguided tests and their implications for the clinical use of this tool is discussed. We interpreted our data to suggest that tumor antigen-monoclonal antibody complexes processed in reactive lymph nodes, anatomically draining the malignant tissue, may cause false-positive tests.

A case of tumor seeding in an abdominal trocar hole after laparoscopic extraction of an incidental gallbladder carcinoma is reported. The high incidence of occult tumors of the gallbladder and appendix warrants caution when dissecting and extracting operative specimens.

Endometriosis may involve the gastrointestinal tract, but only rarely is the appendix affected. The authors report the ultrasonographic appearance of appendicular endometriosis, which was unexpectedly discovered in a 31-year-old woman. The lesion was also demonstrated by computed tomography and an upper gastrointestinal tract radiographic series after barium ingestion. The diagnosis was confirmed by surgery. The authors believe this to be the first description of the ultrasonographic appearance of appendicular endometriosis.

One case of primary adenocarcinoma of the vermiform appendix is presented. The patient, a 55-year-old man, showed non specific symptoms and the diagnosis was made after surgery. Surgical treatment was right hemicolectomy. The patient is still alive and disease-free 12 months after the operation. The Authors review the literature and discuss some clinical aspects of this rare tumor.

Villous adenomas of the vermiform appendix are uncommon. Their malignant potential is unknown and their treatment is controversial. Because of a reported association between adenomas of the appendix and other gastrointestinal neoplasms, long-term surveillance is recommended. A new case of appendicular villous adenoma is reported.

Using a newly available model for determining estimates of radiation absorbed dose of radioisotopes administered intraperitoneally, we have calculated absorbed dose to tumor and normal tissues based on a surgically controlled study of radiolabeled antibody distribution. Ten patients with peritoneal carcinomatosis received intraperitoneal injections of the murine monoclonal antibody B72.3 radiolabeled with 131I. Biodistribution studies were performed using nuclear medicine methods until laparotomy at 4-14 days after injection. Surgical biopsies of normal tissues and tumor were obtained. The marrow was predicted to be the critical organ, with maximum tolerated dose [200 rad (2 Gy) to marrow] expected at about 200 mCi (7.4 GBq). In patients with large intraperitoneal tumor deposits, the tumor itself is an important source tissue for radiation exposure to normal tissues. Local "hot-spots" for tumor-absorbed dose were observed, with maximum tumor-absorbed dose calculated at 11,000 rad (11 Gy) per 100 mCi (3.7 GBq) administered intraperitoneal; however, tumor rad dose varied considerably. This may pose serious problems for curative therapy, especially in patients with large tumor burdens.

A unique case of an infarcted carcinoid of the appendix is presented in which the computed tomography (CT) and clinical findings mimicked an appendiceal abscess. Though unusual, this possibility and appearance should be familiar to the radiologist particularly if percutaneous drainage is considered.

A rare case of appendiceal lymphoma in a patient who presented with lower gastrointestinal bleeding is reported. The findings on double-contrast barium enema, computed tomography (CT), and ultrasound are described and the clinical features of the few previously reported cases of appendiceal lymphoma are discussed.

The authors report six cases of mucus-secreting tumor of the vermicular appendix, in four women and two men (mean age 59 years). All were benign. Pain in the right lower quadrant was the initial sign in 4 cases, while the mucus-secreting tumor was an incidental finding in the other two cases. A mass was palpated in the right lower quadrant in one case. A barium enema was performed in four cases and showed an extrinsic compression of the caecal base in one case, and of the right colon in another case. Four appendectomies, one associated with removal of the adjacent caecal tissues and two right colectomies were performed. Analysis of these six cases and a review of the literature allow us to recall the histologic classification of these tumors, which determines the prognosis and to emphasize the sonographic and CT scan findings which might lead to earlier preoperative diagnosis in the future. Management depends upon the circumstances under which the tumor is discovered, the local anatomy, and the type of tumor. Appendectomy is the treatment most often performed. Faced with a tumor of the appendix, without histologic proof or when the local anatomic conditions increase the risk of opening an abscess, right colectomy is recommended.

In a 51 year old woman a cystic in the right lower abdomen was diagnosed by ultrasound. The patient underwent laparotomy assuming the tumor to be a right adnexal mass. Intraoperatively, a pathological appendix was found. Histologic evaluation of the appendix showed a mucinous cystadenoma with mucocele.