intussusception of the appendix is an uncommon type of intussusception with an incidence of 0.01% ( 1 ) .
although it may clinically mimic more common acute and chronic abdominal conditions , it is an important entity to recognize since it could be discovered as cecal mass and mistaken for a neoplasm .
in korea , two cases of intussusception of the appendix were reported ; these were diagnosed by barium enema ( 2 , 3 ) .
a 17-yr - old female admitted with repeated periumbilical pain , nausea , vomiting and febrile sensation .
physical examination revealed mild periumbilical tenderness without rebound tenderness . in laboratory data , white blood cell count was 12,800/l and the other findings were normal .
simple abdominal radiography and abdominal computerized tomography revealed no abnormality except mild paralytic ileus . the following day
a colonoscopy was performed , which revealed a polypoid lesion in the cecum ( fig .
1 ) . an exploratory laparotomy was performed and it was seen dimple at cecum , the appendix invaginated into the cecum and an appendectomy was performed .
the appendix was 2.5 cm in length , and it showed a chronic inflammation pathologically ( fig .
intussusception of the appendix is a rare entity that is difficult to diagnose preoperatively . in 1858
mckid ( 4 ) first described a complete invagination of the appendix into the cecum of a 7 yr - old boy . in 1890 , the first operation for appendiceal intussusception in a 13-month - old child was reported ( 5 ) .
wright , renshaws , pitts and mcgraw reported successful operations for appendical intussusception ( 6 ) . in 1964 ,
collins ( 1 ) concluded a 40-yr study on 71,000 appendices obtained from surgical and autopsy material and reported prevalence of 0.01% for intussusception of the appendix ; the prevalence of the endometriosis and adenocarcinoma of the appendix were 0.05% and 0.08% , respectively .
intussusception of the appendix may occur at any age , however , the majority of the reported cases reviewed in the earlier literature occurred in the pediatric aged group , with the average of 16 yr ( 5 , 6 , 8) . the condition is more common four to five times in males than in females ( 9 ) .
the signs and symptoms of the intussusception of the appendix are vague , recurrent , cramping abdominal pain , intermittent rectal bleeding and mucus in the stools ( 6 , 9 , 10 ) .
the condition assumes a greater importance in the differential diagnosis of right lower quadrant abnormalities , particularly if the symptoms are subacute or recurring ( 11 ) .
( 12 ) described five possible clinical features : 1 ) acute appendicitis , 2 ) intussusception , 3 ) recurrent right iliac fossa pain , 4 ) intermittent painless rectal bleeding , and 5 ) asymptomatic findings at laparotomy , barium enema , or colonoscopy .
intussusception of the appendix probably occurs by the same mechanism and pathogenesis as intussusception elsewhere and has been reviewed extensively ( 5 , 7 , 13 ) .
many pathological conditions have been considered responsible for its presentation , including abnormal appendiceal peristalsis , irritation of the appendix secondary to fecalith , foreign body , polyp , parasites , and lymphoid hyperplasia , but the appendix may be normal ( 6 , 9 ) .
other causes such as mucocele , appendiceal adenocarcinoma , carcinoid tumor and endometrial implants have not been reported in the pediatric age group .
however , intussusception may occur in an appendix even without an underlying abnormality ( 6 ) .
anatomically , various types of the appendiceal intussusception have been reported ( 5 ) . in 1941 , mcswain ( 8) modified the original classification of the appendiceal intussusception by moschcowitz ( 5 ) , which in turn was simplified by langsam et al .
the tip of the appendix is the intussusceptum and its more proximal portion is the intussuscipiens .
, the proximal portion of the appendix forms the intussusceptum and is received into the distal portion . in type 4 , there is a complete inversion of the appendix into the cecum from progression of types 1 and 2 .
either type 1 or type 2 can result in a complete inversion of the appendix into the cecum thereby resulting in the inside - out appendix as demonstrated in 2 cases ( 14 ) .
intussusception of the appendix has been noted during barium enema , sometimes in asymptomatic patients , and the intussusception has been reduced during the study ( 15 , 16 ) .
levin et al . ( 15 ) reported 11 cases with the characteristic coiled - spring sign in the cecum and nonfilling of the appendix on double - contrast barium enemas .
therefore , this finding defect has to be differentiated from other causes such as polyps , carcinoma , and lymphoma by colonoscopy ( 12 ) .
radiological findings may be : 1 ) no abnormality seen in cecal region without any mention of the appendix ; 2 ) oval or round bosselated intraluminal filling defects , usually in the medial wall of the cecum , with no visualization of the appendix ; 3 ) intraluminal finger - like filling defects within the cecum , usually arising from the medial wall of the cecum ; or 4 ) reduction of the filling defect out of the cecum during fluoroscopy ( 16 , 17 ) .
sonogram has a proven sensitivity for the diagnosis of intussusception , and the typical sonographic appearances are well documented ( 6 , 11 ) .
it enables a physician to identify a lead point within a complex target sign , but there are few publications about the sonographic pattern of intussusception of the appendix ( 6 , 18 ) .
axial sonogram , intussusception of the appendix may present with a permanent multiple concentric sign .
intussusception of the appendix may produce a target like appearance or concentric ring sign on ultrasound examination ( 19 ) .
colonoscopic view of the appendiceal intussusception has often been misdiagnosed as a cecal polyp or a neoplasm ( 20 , 21 ) .
it is important for the endoscopist to remember that the appendiceal intussusception may mimic a cecal polyp , especially if the appendiceal lumen is not identified .
therefore , it is important to make an accurate preoperative diagnosis in order to avoid endoscopic removal and the potential hazards .
pathologically intussusception of the appendix has the following characteristics : 1 ) lesions of the wall - fecaliths , foreign bodies , and peristalsis ; 2 ) lesions of the wall - hypertrophic lymphoid follicles and adenovirus infections affecting the younger age groups ; mucosal polyps , mucoceles , adenocarcinoma , carcinoid , endometriosis , and tuberculosis ( 8 , 9 , 23 ) .
 intussusception of the appendix is an uncommon condition and the diagnosis is rarely made preoperatively . 
 intussusception of the appendix may mimic a neoplastic lesion . 
 colonoscopy is a valuable tool for diagnosis of the appendiceal intussusception . 
 a 17-yr - old female admitted with repeated abdominal pain , nausea , vomiting and febrile sensation . 
 we diagnosed as appendiceal intussusception by colonoscopy , which showed a polypoid tumor ( about 1.5 cm ) in the cecum . 
 this sessile polypoid mass looks like foreskin or glans . 
 we present colonoscopic finding of appendiceal intussusception and review the literature . 
INTRODUCTION
CASE HISTORY
DISCUSSION