an accurate subgroup classification of lymphomas is mandatory because the classification influences prognosis as well as treatment .
the current world health organization classification for lymphomas is based on clinical information such as cytological , histological , and immunophenotypical features and other ancillary studies such as flow cytometry , fluorescence in situ hybridization , and genetic rearrangement testing .
therefore , it is essential to obtain adequate tissue specimens for an accurate pathological diagnosis . a patient presenting with an intra - abdominal lymphadenopathy is a common case scenario in clinical practice . in those who have associated peripheral lymphadenopathy
, a biopsy can be performed under local anesthesia . in the absence of peripheral lymphadenopathy , however , a tissue specimen for diagnosis is more difficult to obtain . up to the 1980s , laparotomy was the only effective method for the diagnosis of intra - abdominal lymphoma .
however , laparotomy is an invasive procedure associated with prolonged hospital stay and subsequent recovery time . in a series of 94 laparotomies for hodgkin 's lymphoma , muskat et al .   reported that early and late ( greater than 30 days ) morbidity were 17% and 5% , respectively .
image - guided percutaneous biopsies have been used because of their low morbidity and acceptable diagnostic yield , but they are often unsuccessful in yielding a definitive diagnosis with complete subclassification
. limitations are mostly related to the lack of adequate amount of tissue specimen for diagnosis .
several studies have reported that laparoscopic intraabdominal biopsy is a safe and effective procedure for providing adequate biopsy sampling . in most previous reports ,
however , a relatively high rate of conversion to laparotomy has been described , usually because of inadequate exposure , insufficient tissue , or postoperative adhesions .
in fact , the transperitoneal approach sometimes seems somewhat troublesome , when the targeted retroperitoneal nodes are small in size or when excessive fatty tissue makes their identification difficult in obese patients . a retroperitoneal approach that allows direct access to
laparoscopic surgery in the urological field involves two different approaches , namely , transperitoneal or retroperitoneal .
the availability of two approaches is a significant advantage when planning the strategy for intraabdominal lymph node biopsy . here ,
we report the feasibility and effectiveness of laparoscopic biopsy using the urological laparoscopic technique for the treatment of patients with clinically suspected intra - abdominal lymphoma .
from october 2010 to april 2015 , a total of 22 patients underwent laparoscopic lymph node biopsy for suspected intra - abdominal lymphoma . with the approval of our institutional review board
all patients were referred to our institution from the department of hematology or internal medicine with imaging studies including routine computed tomography ( ct ) and fluorine-18 fluorodeoxyglucose positron emission tomography ( f - fdg pet ) .
an excisional biopsy of peripheral lymph nodes was performed in two cases , but failed to establish the diagnosis .
none of these patients underwent an imaging - guided biopsy of the abdominal mass prior to laparoscopy .
we adopted a retroperitoneal approach for paraaortic or paracaval masses , because this approach presents direct access to the target organ .
a retroperitoneal space was created by using a preperitoneal distension balloon ( tyco healthcare , mansfield , ma , usa ) in a complete lateral position .
conversely , we used a transperitoneal approach for mesenteric , iliac , or obturator masses . for mesenteric masses ,
a right semilateral position was used , permitting mobilization of the small intestine to the right . for obturator or iliac masses ,
a 10 trendelenburg position was used to retract the bowels cephalad . in most patients ,
whenever possible , an entire node was removed and the base of the node was then clipped ; otherwise , the biopsy consisted of wedge resection sized at least 1 cm . after the biopsy ,
hemostasis at the cut edges of the lymph node was secured by electrocautery . in some cases ,
fibrin glue was used to prevent lymphocele formation or to control bleeding . the use of fibrin glue depended on the surgeons ' preference .
specimens were sent for frozen and permanent sectioning by a pathologist . after confirming that an appropriate tissue specimen had been obtained ,
molecular analyses that included immunoglobulin and t - cell receptor gene rearrangements and analysis of the epstein - barr virus genome were performed in some samples to confirm the diagnosis .
a total of 11 men and 11 women , ranging in age from 51 to 85 years , were included .
one patient had been treated for a previous lymphoma and visited us with suspicion of recurrence . in the other 21 cases ,
biopsy specimens were obtained from the following lymph node sites : 10 paraaortic , 5 paracaval , 3 mesenteric , 2 obturator , 1 common iliac , and 1 perinephric fat .
fifteen patients ( 9 paraaortic , 5 paracaval , and 1 perinephric fat ) underwent surgery via the retroperitoneal approach ( fig .
1 ) , whereas the remaining 7 patients ( 1 paraaortic , 3 mesenteric , 2 obturator , 1 common iliac ) underwent surgery via the transperitoneal approach ( fig .
the median postoperative length of stay was 4 days ( range , 347 days ) .
patients who were not discharged from the hospital were generally transferred to the department of hematology within 5 days for further examination or initiation of treatment .
there were no periprocedural mortalities and we found only 1 important complication of symptomatic lymphocele . a 77-year - old woman developed abdominal fullness and pain on the 13th postoperative day after paraaortic lymph node biopsy
. a ct scan revealed lymphocele in the retroperitoneal space , and a pigtail drainage tube was then placed , which revealed a large amount of serous milky fluid draining at the rate of 1,000 ml / day . after conservative management failed to stop the chylous lymphatic leakage , retroperitoneoscopic lymphostasis was performed on the 24th postoperative day .
fibrin glue was sprayed to pack the exposed paraaortic area until the obvious accumulation of lymphatic fluid disappeared .
twenty patients were found to have malignant lymphoma and one each had metastatic urothelial carcinoma and squamous cell carcinoma of unknown origin .
urological laparoscopic surgery has evolved greatly since the introduction of laparoscopic nephrectomy in 1991 . today , various types of laparoscopic urological surgeries , such as laparoscopic adrenalectomy , radical nephrectomy , nephroureterectomy , radical prostatectomy , and radical cystectomy , are performed daily by an increasing number of urologists in hospitals and medical centers . utilizing this experience , it is easy to approach mesenteric lymph nodes , retroperitoneal lymph nodes below the renal hilar region , or pelvic lymph nodes . with new advances in technology and instrumentation
, some advanced laparoscopic procedures are currently available in high - volume centers with adequate laparoscopic expertise , such as extended pelvic lymph node dissection for bladder cancer   and retroperitoneal lymph node dissection for testicular cancer . in the case of suspected intra - abdominal lymphoma , laparoscopy and image - guided percutaneous biopsy
currently , there are no evidence - based guidelines recommending one technique over the other .
multiple studies have shown percutaneous biopsy to be an adequately sensitive technique for identifying the presence of lymphoma ; however , it is often unsuccessful in yielding a definitive diagnosis with complete subgroup classification . in a series of 263 percutaneous image - guided biopsies used to diagnose suspected lymphoma , a diagnosis
could be made in 90.1% of cases ; however , only 75% of lymphomas could be fully subclassified . in a study
comparing laparoscopic biopsy with percutaneous biopsy for the diagnosis of abdominal lymphoma , significantly more patients in the laparoscopic biopsy group had sufficient tissue for ancillary studies when needed than in the percutaneous biopsy group : 95.5% and 68.2% , respectively . in light of this evidence
, it has been our policy to perform laparoscopic lymph node biopsy at first presentation in the case of isolated abdominal lymphadenopathy with suspicion of lymphoma . in 1988 , salky et al .  
described the first laparoscopic biopsy in a case of retroperitoneal disease . from the late 1990s to the early 2000s , three large case series were reported by general surgeons .
the rate of conversion to open laparotomy , however , is relatively high ( 3.6%17% ) , especially in the case of retroperitoneal lymph nodes .
the primary reasons for conversion are previous surgery , obscure anatomy , inadequate explorations , inadequate sampling , and bleeding . in these studies ,
it may be possible to evade these causes of conversion by using a retroperitoneal approach .
for mesenteric lymph nodes or interaortocaval lymph nodes , the transperitoneal approach may be safer and simpler than the retroperitoneal approach .
although this was a small retrospective study , we consider that our study shows the feasibility of using two approaches appropriately in laparoscopic intra - abdominal lymph node biopsy .
the ability to choose the operative approach according to circumstances represents a clear advantage for urologists .
one patient ( 4.5% ) had a symptomatic chylous lymphocele , which was unsuccessfully managed by dietary intervention and needed surgical intervention . in this case , the retroperitoneal approach was applied for the paraaortic lymph node biopsy .
described surgical exploration of the retroperitoneal space through a direct vision endoscope without gas insufflation for retroperitoneal lymphadenopathy .
lymphorrhea persisting for more than 5 days was observed in 5 of the 118 patients .
the retroperitoneal procedure may be associated with a high risk of lymphorrhea because there is no intraperitoneal space to absorb the lymphatic fluid . in 9 patients , we used fibrin glue to reduce postoperative lymphorrhea , but it was not used in this case .
several prospective studies have addressed the use of a fibrin sealant to reduce lymphadenectomy - related postoperative complications in patients undergoing dissection of the groin , axilla , or paraaortic lesions .
therefore , the use of fibrin glue may be recommended in the retroperitoneal approach for intra - abdominal lymph node biopsy , especially when urgent chemotherapy is required for patients suspected to have high - grade lymphoma .
previous laparoscopic biopsy experiences have shown a high frequency of false - negative diagnoses ( 0%14% ) . in our series , a precise diagnosis was established for all patients , and 20 lymphomas were completely subclassified . to minimize false - negative results ,
it is necessary to collect a sufficient quantity of a specimen tissue and to select an appropriate specimen as a target biopsy site .
f - fdg pet is currently considered the standard modality for not only staging but also evaluating targeted biopsy sites . in an fdg - avid tumor , it is important to select a high fdg uptake lesion as a target site .
furthermore , when multiple lesions are present , it is important to decide from which lesion we can easily and safely perform a biopsy .
a thorough ct and pet evaluation by the surgical team is mandatory prior to laparoscopy , so as to select the surgical approach and the route from which to approach the node .
appropriate use of a transperitoneal or a retroperitoneal approach is safe and effective for laparoscopic lymph node biopsy in patients with suspected intra - abdominal lymphoma .
urologists should participate aggressively in this field , because these two approaches have become standard procedures in urological laparoscopy .
 purposelaparoscopic urologists are familiar with both transperitoneal and retroperitoneal approaches . 
 that experience is an advantage when devising a strategy for intra - abdominal lymph node biopsy . 
 we report the feasibility and effectiveness of laparoscopic biopsy using a urological laparoscopic technique for the treatment of patients with clinically suspected intra - abdominal lymphoma.materials and methodsfrom october 2010 to april 2015 , a total of 22 patients underwent laparoscopic biopsy for suspected intra - abdominal lymphoma . 
 we adopted a retroperitoneal approach for paraaortic or paracaval masses , whereas we used a transperitoneal approach for mesenteric , iliac , or obturator masses . whenever possible , an entire node was removed ; otherwise , the biopsy consisted of wedge resection sized at least 1 cm3.resultsbiopsy specimens were obtained from the following lymph node sites : 10 paraaortic , 5 paracaval , 3 mesenteric , 2 obturator , 1 common iliac , and 1 perinephric fat . 
 laparoscopic lymph node biopsy was completed in all patients , and there were no conversions to open surgery . 
 the median operating time was 97 minutes ( range , 62167 minutes ) . 
 the estimated blood loss was < 50 ml in all cases . 
 postoperatively , one patient ( 4.5% ) had symptomatic chylous lymphocele that required surgical intervention . 
 precise diagnosis was established for all patients : malignant lymphoma in 20 patients and metastatic urothelial carcinoma and squamous cell carcinoma of unknown origin in 1 patient each . 
 all lymphomas could be fully subclassified.conclusionsappropriate use of the transperitoneal or retroperitoneal approach is safe and effective for laparoscopic lymph node biopsy in patients with suspected intra - abdominal lymphoma . 
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSIONS