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Paper text:
a 44-year - old male patient was admitted to the hospital for surgical removal of a duodenal submucosal tumor found incidentally on duodenoscopy . an abdominal ct scan showed a well - defined heterogeneous retroperitoneal enhancing mass measuring 3.6  4.5  3.1 cm in the paraaortic space ( fig .
he had a 20-year history of smoking and was on medication for hyperlipidemia , but had no other significant past medical or family history .
prior to anesthetic induction , the patient 's blood pressure ( bp ) was 130/75 mmhg and his heart rate ( hr ) was 74/min .
the modified allen test was positive and a 20-gauge catheter was placed into the radial artery for continuous bp monitoring .
desflurane 8 vol% and remifentanil 0.2 g / kg / min were continued for 3 minutes prior to endotracheal intubation .
desflurane 4 vol% , n2o 50% , and remifentanil 0.06 g / kg / min were used for maintenance of anesthesia .
bispectral index was maintained at 35 - 50 . during the initial manipulation of the tumor , at the beginning of the surgery ,
the patient became hypertensive , with a bp of 250/120 mmhg , and tachycardic , with a hr of 100/min .
the hypertension was treated with a combination of sodium nitroprusside infusion ( 0.5 g / kg / min ) , labetalol hydrochloride ( 10 mg of labetalol in two doses of 5 mg each ) , remifentanil infusion ( 0.3 g / kg / min ) , and increased desflurane concentration up to 9 vol% .
although the bp decreased to 155/100 mmhg following the infusion , there was an increase in the systolic bp ( above 180 mmhg ) and the hr ( 95 - 105/min ) each time the surgeon manipulated the tumor . despite the adequate depth of anesthesia and anti - hypertensive therapy ,
subsequently , an additional dose of nicardipine hydrochloride 300 g was administered , and isosorbide dinitrate 0.2 g / kg / min infusion was maintained . after the administration of nicardipine , the bp initially decreased to 130/80 mmhg , and systolic bp
was maintained at 140 - 150 mmhg thereafter . an arterial blood gas analysis performed at this point showed ph 7.35 , paco2 40 mmhg , pao2 168 mmhg , and oxygen saturation 99% on fio2 0.5 .
desflurane 9 vol% , remifentanil 0.3 g / kg / min , sodium nitroprusside ( 0.1 - 0.3 g / kg / min ) and isosorbide dinitrate 0.2 g / kg / min were administered continuously , and the bp remained stable at around 130 - 160 mmhg systolic .
there were no changes in the ecg after the resumption of surgery , and the troponin i levels checked afterwards remained below 0.20 ng / ml .
as the bp gradually decreased with ligation of the tumor , desflurane and remifentanil were tapered .
one hundred and fifty minutes after the start of the surgery , the tumor was completely removed . following tumor removal ,
estimated blood loss during the surgical procedure was about 500 ml . in order to improve the patient 's hemodynamic parameters , volume expanders ( 500 ml ) and crystalloid fluids ( 1,000 ml ) were given , and 8 mg of ephedrine was administered intravenously .
after these procedures , the bp returned to 140/87 mmhg and the hr returned to 88/min .
the patient 's vital signs were maintained with desflurane 4 vol% and remifentanil 0.03 g / kg / min until the surgery was completed .
an undiagnosed extra - adrenal pheo was suspected based on the hypertensive crisis caused by tumor manipulation during the surgery .
a biopsy showed that the tumor was a well - encapsulated , solid mass measuring 5.5  4.0  3.7 cm .
immunohistochemical staining revealed the neuroendocrine markers synaptophysin and chromogranin , and a positive cd56 confirmed the diagnosis of pgl .
the patient was transferred to the general ward on postoperative day ( pod ) 2 and was discharged on pod 11 without any complications .
a follow - up appointment was scheduled for six months after the surgery , to investigate any evidence of recurrence and to monitor signs of lymph node metastasis .
the most common catecholamine secreted is norepinephrine , and the classic triad of symptoms of catecholamine excess is headache , palpitations , and sweating . sustained or paroxysmal hypertension has been reported in 80 - 100% of patients . the main manifestation of sympathetic pgl is hypertension , and this type of tumor is usually localized in the thorax or the abdomen . while parasympathetic pgls are mostly localized around the head and neck , these tumors are nonfunctional , and biochemically silent .
there are cases , therefore , in which the classic triad of symptoms does not occur .
in addition , some cases are either asymptomatic or ambiguous , with confounding factors including psychiatric disorders , anxiety , facial pallor , weight loss , polyuria , hyperglycemia , secondary erythrocytosis , stroke , and cardiomyopathy , making a proper diagnosis difficult . in such cases ,
the patient may be unaware that he or she has pgl until it is discovered incidentally from an imaging study such as a ct or mri . however , specific patient interviewing could help trigger the suspicion of pgl .
there is also a special need for a physical examination to determine the presence of cardiovascular side effects from such a tumor . in hindsight , the patient described here showed a borderline bp elevation before surgery ; therefore , a physician should not overlook borderline elevation of the bp in patients .
also , pgl or pheo should be considered in patients with a history of resolved takotsubo cardiomyopathy and abdominal mass . in 2009 , choi et al .   reported a case in which a severe catecholamine - induced cardiomyopathy barely responded to high vasopressin and epinephrine .
therefore , to evaluate the possibilities of such cardiac abnormalities , an echocardiogram must also be performed .
pheo / pgl are associated with genetic syndromes such as neurofibromatosis 1 , von hippel - lindau ( vhl ) disease , multiple endocrine neoplasia type 1 ( men 1 ) and type 2 ( men 2 ) .
abdominal pgls are also associated with succinate dehydrogenase subunit d ( sdhd ) b mutation .
thus , medical information obtained through preoperative genetic counseling can aid in diagnosing pheo / pgl . in the case
described here , the patient was admitted to the hospital for surgical treatment of an incidental duodenal mass .
the case was uneventful not only prior to the surgery , but also during endotracheal intubation and the surgical incision . however , direct manipulation of the tumor led to hypertensive crisis in this patient .
this finding is believed to be due to the sudden excessive secretion of catecholamines from the tumor ( extra - adrenal or retroperitoneal pgl ) , which was misdiagnosed as gist .
gists are large - sized tumors ( > 5 cm ) , arising from the stomach , with heterogeneous enhancement ( 84% ) and central necrosis ( 37% ) .
large - sized pgls adjacent to the stomach , accompanied by no specific signs of catecholamine secretion , are therefore often misdiagnosed as tumors of neural or mesodermal origin , such as gist or other soft tissue sarcomas .
furthermore , when there are neither symptoms of catecholamine excess nor histologic diagnosis , gist has a similar radiographic appearance to pgl .
the genetic association of nonfamilial pgl , gist , and pulmonary chondroma ( carney triad ) has been described in a very small number of patients , but the underlying genetic factor has not yet been revealed .
what was initially perceived by physicians to be gist turned out , after biopsy , to be pgl . in a case described in 2009 ,
lowenthal et al .   believed that a patient with anxiety symptoms and a perigastric mass had gist .
while undergoing a surgical resection , the patient experienced a hypertensive crisis during the initial tumor manipulation . from the pathologic examination ,
yoo et al .   discovered an incidental duodenal polypoid mass that they thought was an adenoma .
there are reports of pgl occurring not only in the duodenum but also in the liver , urethra , cerebellopontine angle , cauda equina , and larynx , among other sites .
therefore , the surgeon must be aware of the fact that one could encounter pgl in unexpected parts of the body during surgery .
imaging studies for localizing the tumor and staging the disease are important , and the conventional work - up with ct or mri is recommended .
since i - metaiodobenzylguanidine ( mibg ) shows higher specificity in confirming catecholamine - secreting adrenergic tissue , this is the method of choice for diagnosis .
however , finding the correlation between the symptoms and laboratory values is considered the most important , even if pgl is seen on a ct . in cases where pgl is suspected due to a sudden hypertensive crisis during surgery
, one must decide whether to proceed with the surgical procedure or to stop the surgery and restart it after proper management of the crisis .
in the case discussed here , the surgeon continued with the surgical procedure because the patient 's vital signs were stable after the infusion of short - acting sodium nitroprusside and nicardipine hydrochloride .
sodium nitroprusside is effective in arteriolar dilatation and in suppressing the hypertensive response due to circulating catecholamines .
there have been recent reports that nicardipine hydrochloride suppresses the secretion of norepinephrine in pheo / pgl , and its use has therefore increased .
surgical procedures involving an unexpected pgl without proper preoperative management , however , lead to an increase in morbidity and mortality .
elective surgical procedures should be canceled or delayed until the origin of the hypertensive episode can be clarified ; furthermore , a differential diagnosis must be made and proper preoperative medication with 1-blockers must be administered to the patient . when proper preoperative management is done , perioperative mortality can be reduced from 45% to 0 - 3% .
once the diagnosis of pgl has been confirmed , complete surgical resection of the tumor is the treatment of choice . to minimize the chances of cerebrovascular catastrophes and/or cardiovascular complications such as arrythmias , hemodynamic instability , and even hypertensive crisis during the perioperative period , at least 1 - 2 weeks of preoperative medical treatment with a nonselective 1-adrenergic blocker ( phenoxybenzamine ) or a selective post - synaptic 1-adrenergic blocker ( doxazosin , prazosin , or terazocin ) is recommended .
after adequate -blockers have been administered , -blockers can be added to prevent catecholamine - induced arrhythmias or reflex tachycardia , which are the side effects of -blockers .
although the majority of pgl are benign tumors , they may also be malignant , especially in children .
several imaging studies , as well as cytologic and histologic studies by biopsy , are useful in suggesting malignancy .
the combination of large size , heterogeneous density , irregular margins , and distant metastasis increases the possibility of malignancy , but the presence of distant metastasis is the most important factor .
chromogranin a is a valuable tumor marker that correlates with size and malignancy , and is useful for detecting sdhb - related pgl , which is biochemically silent .
this marker may improve the sensitivity of diagnosis , and it can be used effectively to monitor for recurrence during long - term follow - up . although the initial therapy recommended for pgl is surgical resection , in cases of metastatic or unresectable disease , i - mibg therapy is the standard alternative therapy option .
careful follow - up is needed in these situations . in conclusion , pgl is very difficult to diagnose during preoperative patient evaluation , as it has either no symptoms or atypical symptoms .
therefore , if acute hemodynamic instability , such as malignant hypertension and tachycardia , occurs during induction of anesthesia or surgical manipulation , particularly in the case of gist surgery , one should suspect pgl .
being aware of the lesion and the potential for hypertensive crisis may prevent intraoperative cardiac disaster . in order to minimize the risk of pgl removal , anticipation by the anesthesiologist and guarded manipulation by the surgeon are essential .
although paraganglioma ( pgl ) , an extra - adrenal retroperitoneal pheochromocytoma ( pheo ) , is a rare catecholamine - secreting neuroendocrine tumor , it can cause severe hypertensive crisis during anesthesia or surgery if undiagnosed preoperatively . 
 extraluminal perigastric masses may be presumed to be gastrointestinal stromal tumors ( gists ) or soft tissue sarcomas even when histologic confirmation is not possible . 
 therefore , without a histologic diagnosis or symptoms of excessive catecholamine secretion , pgl may be mistaken for gist . 
 we report a case of preoperatively undiagnosed pgl which caused hypertensive crisis during anesthesia for retroperitoneal mass excision .