the function of appendix in humans is unclear , although it is thought to possibly play a role in the immune system . the majority of appendiceal tumors are carcinoids , while the remaining 10% to 20% are mucinous cyst - adenocarcinoma , adenocarcinoma , lymphosarcoma , paraganglioma , and granular - cell tumors . most common symptoms include acute pain in right lower quadrant and other symptoms of inflammation like fever , leukocytosis , and so forth . if a mass in the appendix is encountered incidentally during the course of abdominal surgery , an appendectomy is performed with frozen - section analysis of the mass . however , if lymphoma or larger carcinoid was identified , chemotherapy or more extensive surgery will be required . when the mass is adenocarcinoma , the treatment algorithm is less defined as the data remain controversial . we are reporting a 46-year - old african - american male presented to the emergency room with lower back pain secondary to a motor vehicle accident in 2009 . after admission , patient complained of right lower quadrant pain , low - grade fever , and nausea . the surgical pathology showed adenocarcinoma of appendix , moderately differentiated with no lymphovascular invasion , and acute appendicitis . the tumor was found to be 2.3  cm , grade 2 , mucin - producing adenocarcinoma . the patient underwent staging ct scans of the chest , abdomen , and pelvis with contrast which did not reveal any evidence of residual malignancy . because of the size of the tumor and the grade , we offered him to have right hemicolectomy . after 3 months of followup , he remained asymptomatic and did not keep his appointments after that . cancer of the appendix is very rare and is typically found incidentally in approximately 1% of appendectomies . according to a report published by the national cancer institute using the surveillance , epidemiology , and end results ( seer ) database , appendiceal neoplasms account for approximately 0.4% of gastrointestinal tumors . carcinoids are by far the most common , accounting for approximately 66% , with cyst - adenocarcinoma accounting for 20% and adenocarcinoma accounting for 10% . then there are the rare forms of cancers which include adenocarcinoid , signet ring , non - hodgkin 's lymphoma , ganglioneuroma , and pheochromocytoma . benign primary processes are mainly mucinous epithelial neoplasms , also called adenomas , cystadenoma , and benign neoplastic mucocele ( table 1 ) . the majority of primary cancers of the appendix occur in 5565 years of age , except for malignant carcinoid , which has a mean age diagnosis of 38 . men and women seem to be at equal risk for all appendiceal neoplasms except for malignant carcinoid which may have woman to man ratio in excess of 3  :  1 , depending on the studies that are analyzed . in 1907 , german pathologist dr . oberndorfer described a collection of tumors he found on the small intestine as looking like carcinoma but also exhibiting features of benign adenomas , as carcinoid ( carcinoma - like ) . in 1914 , dr gosset and dr mason postulated that carcinoid tumors were made up of enterochromaffin cells , a type of neuroendocrine cells within the lamina propria and submucosa . it has been widely accepted that the majority of carcinoids arise in the appendix , ; however , recent data suggests that other locations , such as the rectum and small intestine may actually be more common . in a study by mggard et al . , 11,427 cases were analyzed , and it was found that 44.7% of tumors were found in the small intestine , 19.6% in the rectum , 16.7% in the appendix , 10.6% in the colon , and 7.2% in the stomach . data from the seer database also suggest that there is a greater proportion of pulmonary and gastric carcinoids compared to appendiceal carcinoids , however , these changes may be due to variation in reporting as benign looking carcinoids were not added to the seer database until 1986 . the incidence and prevalence of carcinoid tumors have conflicting statistics . in many of the older articles , the inconsistency is due in part to the fact that the disease is mostly asymptomatic and can remain asymptomatic for many years , so the incidence rate is more likely to be higher . when the tumor is located in the tip of the appendix , which it is in approximately 75% of the cases , it generally does not present with symptoms until it becomes metastatic . when the tumor is located at the base of the appendix , it can occlude the lumen and give the patient similar signs and symptoms of appendicitis . in these patients , the diagnosis of carcinoid cancer is typically made by pathology after an appendectomy has been performed . in rare cases , the carcinoid tumor also produces vasoactive substances such as histamine , prostaglandins , kallikrein , bradykinins , substance p , gastrin , corticotrophin , and neuron - specific enolase . the lungs and the liver are able to clear many of these agents along with the serotonin , therefore , able to avoid carcinoid syndrome . it is not until these organs have carcinoid metastasis that the ability to clear these substances becomes impaired , and symptoms of carcinoid syndrome become apparent . as stated before , diagnosis of carcinoid tumor of the appendix is usually made after an appendectomy . when the patient presents with signs and symptoms of appendicitis , a cat scan of the abdomen is typically performed . these imaging studies usually show a process of acute appendicitis or have associated calcifications [ 10 , 11 ] .   in a patient with suspected carcinoid syndrome , measuring the urinary excretion of 5-hiaa and serum chromogranin a levels can be useful in diagnosis . an octreoscan may be beneficial ; however , its results are not always reliable . the extent of surgery is based upon the size of the tumor , but since the majority of carcinoid tumors are found incidentally on simple appendectomies , a second surgery is sometimes needed . the national comprehensive cancer network ( nccn ) guidelines for treatment of carcinoid tumors state that tumors < 2  cm confined to the appendix can be treated with simple appendectomy with no followup required . for tumors > 2  cm , or those with extra - appendigeal invasion , an appendectomy with right hemicolectomy and cytoreductive surgery is necessary . post - operatively , a 3 month followup which includes a history and physical ( h&p ) , ct of the abdomen , and tests for markers ( 5-hiaa and chromogranin a ) should be completed .   for patients with metastatic disease , somatostatin , an 18 amino - acid peptide , binds to somatostatin receptors to block the secretion of hormones such as growth hormones , gastrin , insulin , and glucagon . octreotide , an eight - amino - acid , long - acting somatostatin analogue , works through g - protein activation on somatostatin receptor subtypes 2 , 3 , and 5 . octreotide was effective in decreasing symptoms in 88% of patients and decreasing the urinary 5-hiaa in 72% of patients . in patients who do not respond to octreotide , interferon - alpha has been added with some positive results ; however , as stated by mayer , this therapy comes at a cost of side effects which may include fever , fatigue , anorexia , and weight loss . if the tumor is confined to the appendix , the disease is said to have 94 percent 5-year survival rate . for patients with regional disease , there is an 85 percent 5-year survival rate , and for distant metastasis , which occurs in approximately 4% of the time in appendiceal carcinoid - tumors , there is a 34 percent 5 year survival rate . the endothelium of the vermiform appendix is composed of masses of lymph tissue and is lined by mucous secreting columnar cells . changes to the columnar cells layer cause the four different types of pathology listed below . many consider these changes to be a spectrum of disease much like colonic polyp formation and progression to carcinoma in colon cancer . like colon cancer , there are both hyperplastic and adenomatous changes at the cellular level . all of these changes cause the formation of a mucocele , which is defined as a dilation of the appendix due to excessive mucinous production . the mucin builds up due to a malignant or non malignant obstruction of the outflow tract . retention cyststhey occur when there is a nonmalignant obstruction of the outflow tract of the appendix . they occur when there is a nonmalignant obstruction of the outflow tract of the appendix . the vast majority of mucoceles measure less than 2  cm , and those that exceed 2  cm are more likely to be neoplasms [ 10 , 11 ] . most are clinically asymptomatic and are found incidentally as palpable masses in the lower right quadrant or on imaging performed for other reasons . on plain abdominal films , mucoceles are difficult to appreciate . ct and mri are more effective in identifying the extent of the mass . villous hyperplasiait is also called hyperplastic polyp , and has many of the same qualities of colonic polyps . the involvement is isolated to the mucosa . instead of a fecalith causing the obstruction as seen in retention cysts , the obstruction is caused by the hyperplastic polyp . it is also called hyperplastic polyp , and has many of the same qualities of colonic polyps . instead of a fecalith causing the obstruction as seen in retention cysts , the obstruction is caused by the hyperplastic polyp . much like the villous hyperplastic polyp , the growth itself is what causes the formation of a mucocele . histologically , the lesion is benign ; however , there may be a continuum to cystadenocarcinomas . rupture of the appendix can cause a phenomenon called pseudomyxoma peritonei which will be discussed later . much like the villous hyperplastic polyp , the growth itself is what causes the formation of a mucocele . histologically , the lesion is benign ; however , there may be a continuum to cystadenocarcinomas . rupture of the appendix can cause a phenomenon called pseudomyxoma peritonei which will be discussed later . adenocarcinomaof the appendix is very rare , accounting for 0.5% of all gastrointestinal cancers . within the adenocarcinoma malignancies there are three subtypes :   mucinous ( 55% ) , colonic type ( 34% ) , and adenocarcinoid ( 11% ) which has a mixed morphology . the mean age of diagnosis is in the fifth decade of life , with an even male to female ratio for all but colonic type , which may have a higher incidence in men . the incidence of adenocarcinoma has been stated to be from 0.004% to 0.08% . 
  of the appendix is very rare , accounting for 0.5% of all gastrointestinal cancers . within the adenocarcinoma malignancies there are three subtypes :   mucinous ( 55% ) , colonic type ( 34% ) , and adenocarcinoid ( 11% ) which has a mixed morphology . the mean age of diagnosis is in the fifth decade of life , with an even male to female ratio for all but colonic type , which may have a higher incidence in men . mucinous adenocarcinomait is the malignant counterpart to the mucinous adenoma . both present with similar symptoms . adenocarcinoid , also called goblet cell carcinoid , has features of both carcinoid tumor and mucinous adenocarcinoma . they account for 5% of cancers of the appendix , with an average age diagnosis of 58 years , and an even distribution between men and women . it is the malignant counterpart to the mucinous adenoma . both present with similar symptoms . adenocarcinoid , also called goblet cell carcinoid , has features of both carcinoid tumor and mucinous adenocarcinoma . they account for 5% of cancers of the appendix , with an average age diagnosis of 58 years , and an even distribution between men and women . as is the case with most cancers of the appendix , the most common presentation is that of acute appendicitis . those with mucinous adenocarcinoma may present with a gradually distending abdomen which may be seen with pseudomyxoma peritonei . the mucinous type , also called mucinous cyst - adenocarcinoma , causes a mucocele by the neoplasm occluding the narrow lumen which allows the mucin to build up and distend the appendix . perforation may occur allowing the spill of cancerous cells out into the peritoneum , which creates the condition of pseudomyxoma peritonei . these cells then seed the organs of the peritoneum and continue to produce the mucin . as the mucin accumulates , the abdomen becomes distended which is referred to as  jelly belly  . instead , they are more likely to present with a focal mass in the right lower quadrant . adenocarcinomaadenocarcinoma of the appendix is rarely diagnosed preoperatively . in a study by nitecki et al . , none of the 96 patients with adenocarcinoma of the appendix were diagnosed preoperatively , and it was only considered in the differential diagnosis in 10 patients . adenocarcinoma of the appendix is rarely diagnosed preoperatively . in a study by nitecki et al . , none of the 96 patients with adenocarcinoma of the appendix were diagnosed preoperatively , and it was only considered in the differential diagnosis in 10 patients . if there is a superinfection associated with the malignancy , there may be air bubbles present on the ct . if the patient presents with a distended abdomen due to pseudomyxoma peritonei , a ct would show widespread heterogeneous locules in the peritoneal cavity [ 10 , 11 ] . since there are no imaging studies specific for diagnosing adenocarcinomas , the final diagnosis is most often made postoperatively on microscopic examination . it has been generally accepted that a right hemicolectomy is the preferred surgical intervention for all subtypes of adenocarcinoma . while some surgeons suggest that a simple appendectomy is sufficient for tumors exhibiting only local disease , many studies have shown that there is a clear survival benefit to the addition of a hemicolectomy [ 14 , 17 , 18 ] . in a study by nitecki , these studies have found that the colonic and goblet cell subtypes are invasive , and approximately half the patients present with nodal metastasis . however , there are some studies that disagree . gonzalez - moreno and sugarbaker found that those patients with mucinous type cancer had no survival benefit from hemicolectomy versus appendectomy . they further mention that hemicolectomy is recommended in those patients where ( 1 ) it is necessary to clear the tumor or perform complete cytoreduction ; ( 2 ) lymph node involvement is demonstrated by histopathological examination of the appendiceal or ileocolic lymph nodes ; or ( 3 ) a nonmucinous subtype is identified by histopathological examination .   in a study done by pahlavan and kanthanon adenocarcinoid tumors , he states that even though goblet cell carcinoma is an aggressive tumor , a simple appendectomy is appropriate in most cases . however , he further states that a right hemicolectomy should be performed in the following scenarios : ( 1 ) cellular undifferentiation , ( 2 ) increased mitotic activity , ( 3 ) involvement of the base of the appendix , ( 4 ) lymph node metastasis , or ( 5 ) tumor size greater than 2  cm . these guidelines allow the surgeon some direction in deciding whether or not to reoperate after a patient has had an appendectomy for an apparent appendicitis . while there are small studies and anecdotal case reports that suggest a response to regimens containing 5-fu , the role of chemotherapy has yet to be clearly defined . most oncologists agree that in the presence of nodal involvement , systemic and intraperitoneal chemotherapy regimens should be used [ 14 , 16 , 20 ] . sugarland suggests postoperative intraperitoneal chemotherapy in the setting of pseudomyxoma peritonei , as long as cytoreduction and debulking have been accomplished , reducing recurrence rates . mucinous adenocarcinoma is considered to have a more favorable prognosis because it does exhibit hematogenous or lymphatic spread [ 16 , 17 ] . while it would be natural to assume that those patients with intraperitoneal seeding due to appendiceal perforation , would have a worse prognosis versus those who did not . however , in a study by nitecki and others , there actually was no difference in 5-year survival rates between the two groups . goblet cell subtype is considered to have a worse prognosis with one study listing a 55% 5-year survival rate while pahlavan states a 6080% 5-year survival rate [ 17 , 20 ] . the discrepancy may be due to differences in lymph node involvement for the two studies . the first had 43% lymph node involvement where pahlavan only showed an 8.76% involvement . the stomach is the most common , followed by the small intestine , pharynx , colon , and esophagus . lymphoma of the appendix is almost exclusively non - hodgkin 's b - cell lymphoma , more specifically , burkitt 's lymphoma . the incidence of primary appendiceal lymphoma has been estimatedat 0.015% of appendectomy specimens . men are more likely to develop appendiceal lymphoma over women by 1.5  :  1 , with a median age onset of 18 years . the stomach is the most common , followed by the small intestine , pharynx , colon , and esophagus . lymphoma of the appendix is almost exclusively non - hodgkin 's b - cell lymphoma , more specifically , burkitt 's lymphoma . the incidence of primary appendiceal lymphoma has been estimatedat 0.015% of appendectomy specimens . men are more likely to develop appendiceal lymphoma over women by 1.5  :  1 , with a median age onset of 18 years . as so many other primary tumors of the appendix , patients typically present with symptoms similar to acute appendicitis . patients may also present with a more insidious onset of pain in the right iliac fossa for a few months and an associated palpable mass in the right lower quadrant . when imaging is done , the appendix demonstrates prominent enlargement , while it maintains the vermiform appearance [ 10 , 11 ] . on ultrasound , the diffuse thickening is hypoechoic and often mimics the cystic dilation of the lumen seen in mucoceles .   as with all lymphoma 's the classic combination of cyclophosphamide , doxorubicin , vincristine , and prednisone ( chop ) has been used for many decades , and since the groupe d'etude des lymphomas de l'adulte study , rituximab has been added . rituximab , a monoclonal antibody against cd20 , was found to increase complete response rates from 64% to 76% . it was also found that the chop plus rituximab increased event free states and overall survival . the combination of chop and rituximab is now the standard of care for large b - cell lymphoma in the us . for burkitt 's lymphoma , primary signet ring cell carcinomaprimary signet ring cell carcinoma   of the appendix is a very rare cancer . according to the data gathered from the seer database , the incidence is approximately 0.15 , with an average age of 59 , and there is no male or female preference . of all the subtypes of appendiceal cancers , signet ring had the lowest percentage of localized disease at 14% , and the highest percentage of distant disease at 60% . the most common presentation is of acute appendicitis , and the recommended surgical intervention is of a right hemicolectomy . of all the subtypes , signet ring had the lowest overall 5-year survival rate at 18% . the role of chemotherapy as a treatment in signet ring cancers of the appendix has not been determined . primary signet ring cell carcinoma   of the appendix is a very rare cancer . according to the data gathered from the seer database , the incidence is approximately 0.15 , with an average age of 59 , and there is no male or female preference . of all the subtypes of appendiceal cancers , signet ring had the lowest percentage of localized disease at 14% , and the highest percentage of distant disease at 60% . the most common presentation is of acute appendicitis , and the recommended surgical intervention is of a right hemicolectomy . of all the subtypes , signet ring had the lowest overall 5-year survival rate at 18% . the role of chemotherapy as a treatment in signet ring cancers of the appendix has not been determined . ganglioneuromait is an extremely rare cancer that is associated with neurofibromatosis , men 2b , congenital defects , carcinomas , and various polyp forming diseases . a search of the literature showed only three case reports of ganglioneuromas involving the appendix , all being the neurofibromatosis type 1 [ 2628 ] . two of the cases presented as discomfort in the lower right quadrant , while the third presented as a palpable mass found on physical exam . all three patients underwent surgical removal of the tumor and the involved surrounding tissue . it is an extremely rare cancer that is associated with neurofibromatosis , men 2b , congenital defects , carcinomas , and various polyp forming diseases . a search of the literature showed only three case reports of ganglioneuromas involving the appendix , all being the neurofibromatosis type 1 [ 2628 ] . two of the cases presented as discomfort in the lower right quadrant , while the third presented as a palpable mass found on physical exam . all three patients underwent surgical removal of the tumor and the involved surrounding tissue . in those patients with neurofibromatosis 1 and men 2b , pheochromocytomas are also prevalent and may be found as a primary cancer of the appendix . this is extremely rare , and there is very little data available to extrapolate meaningful conclusions at this time . appendix cancer is rare , and most commonly found incidentally in an appendectomy specimen that was obtained for an unrelated condition . the main histologic types are carcinoids , adenocarcinomas , adenocarcinoids , cystadenomas , and cystadenocarcinomas . for appendiceal carcinoids , reoperation and right colectomy is recommended for tumors larger than 2  cm and for smaller tumors with mesoappendiceal invasion . the spectrum of epithelial tumors of the appendix ranges from the benign mucocele to an aggressive adenocarcinoma . simple appendectomy , taking care not to rupture the tumor intraoperatively , is sufficient therapy for benign appendiceal mucoceles , cystadenomas , and some cystadenocarcinomas . a right colectomy is indicated for cystadenocarcinomas with mesenteric or adjacent organ involvement and complicated mucoceles with involvement of the terminal ileum or cecum , cystadenocarcinomas . pseudomyxoma peritonei ( pmp ) is a unique condition characterized by diffuse collections of gelatinous material in the abdomen and pelvis , associated with mucinous implants on the peritoneal surfaces . the term should be reserved for the clinical situation in which a ruptured cystadenoma seeds the peritoneal cavity with mucus - producing epithelial cells , termed diffuse peritoneal adenomucinosis ( dpam ) . the natural history is one of indolent but progressive growth , and if left untreated , this is a fatal condition . this treatment is not curative but aims to limit the buildup of mucus and its pressure effect . a more aggressive approach using radical surgical cytoreduction of all intraabdominal and pelvic disease and intraperitoneal heated chemotherapy ( iphc ) has been adopted by some clinicians , aiming for cure . although randomized trials have not been conducted , five - year survival rates of 70 to 86 percent have been reported for highly selected patients . the importance of surgical technique and surgeon experience to the success and safety of this approach can not be overemphasized . in contrast to other appendiceal tumors , adenocarcinomas more often present with a clinical picture of acute appendicitis . the role of adjuvant chemotherapy for adenocarcinoma of the appendix is unknown . despite the lack of available data , many oncologists recommend adjuvant 5-fu - based chemotherapy particularly for patients with node - positive intestinal type adenocarcinoma , extrapolating from data on adjuvant chemotherapy for node - positive colon cancer . optimal treatment of patients with intraperitoneal dissemination of appendiceal adenocarcinoma ( mucinous peritoneal carcinomatosis as distinguished from dpam ) is unclear . selected patients treated with aggressive surgical cytoreduction and iphc may do well - long term , but patient selection and the experience of the treating team are critical . in uncontrolled series from experienced institutions , long - term survival rates in although mucinous appendiceal adenocarcinomas have been thought to be relatively chemotherapy refractory , case reports suggest some level of benefit for therapy in individual patients . no standard of care is established due to rare frequency of occurrence , our case   and the literature review are a summary of the appendix tumor , and the management based more on personal opinion of the oncologists who deal with this rare type of tumor , hopefully , would   help in the future to create clinical trials to establish more evidence - based medicine help in the management .
cancers of the appendix are rare . 
 most of them are found accidentally on appendectomies performed for appendicitis . when reviewed 
 , majority of the tumors were carcinoid , adenoma , and lymphoma . 
 adenocarcinomas of appendix are only 0.08% of all cancers and the treatment remains controversial . 
 here we are reporting a 46-year - old male presented with symptoms of appendicitis , diagnosed with adenocarcinoma of the appendix . 
 the patient was treated with appendectomy and refused further surgical intervention to complete hemicolectomy . 
 up to date , he remains asymptomatic . 
 we performed literature review of the tumors of the appendix . 
 most of the benign conditions are treated with surgery alone . 
 lymphomas require chop - like chemotherapy and carcinoid syndrome treatment with somatostatin analogues . 
 it is generally recommended that right hemicolectomy is the preferred treatment for adenocarcinoma of appendix . 
 the role of chemotherapy is unclear due to lacking randomized trials but seems to be accepted if there is lymph node involvement or peritoneal seeding .