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leiomyoma is the most common benign tumor of the esophagus ( 6780% ) ; it represents 0.41% of all esophageal tumors .
its differential diagnosis should be established with gastrointestinal stromal tumors ( gist ) , and other benign tumors .
the criteria to resect or not a leiomyoma is based on the symptoms it produces , especially dysphagia , and on the need to exclude malignancy .
positron emission computed tomography ( pet / ct ) using fluorine-18-fluorodeoxyglucose ( fdg ) provides information on tissue metabolic activity and can help in the differential diagnosis .
we report a case of esophageal submucosal tumor that showed a markedly increased fdg uptake on initial preoperative workup pet / ct . based on this information we opted for a surgical mini - invasive exploration .
a 54 year old man was admitted to another hospital for abdominal trauma following a motor vehicle accident .
his past medical history includes hepatic steatosis secondary to excess alcohol intake but no history of tobacco smoking . on admission a thoraco - abdominal ct showed several fractured ribs , an incidental gastro - esophageal tumor and a ruptured spleen for which the patient underwent a splenectomy via open midline laparotomy .
the tumor was described as a bulky partially calcified mass measuring 45    52    29  mm , poorly vascularized and seemingly extrinsic to the esophageal lumen coming in contact with the anterior pericardium ( fig .
multiple celiac lymph nodes were also noted , the largest measuring 16  mm . following the patient 's postoperative recovery ,
a follow - up ct showed the same unchanged celiac lymph nodes and an increase in size of 4  mm of the previously described tumor .
further investigations included an upper endoscopy confirming the submucosal location of the tumor . an endoscopic ultrasonography ( fig .
2 ) disclosed a heterogeneous submucosal tumor with well - defined margins in the muscularis mucosa located at 3540  cm from the dental arcade .
a differential diagnosis of degenerated gist versus leiomyoma / leiomyosarcoma or post - traumatic hematoma was made .
after undergoing the above mentioned investigations namely the endoscopic ultrasound and both abdomino - pelvic tomodensitometries the patient was referred to our institute for further management . a pet / ct scan ( fig .
3 ) showed an abnormally increased fdg uptake ( suv  =  6.1 ) in the tumor with no other metabolically active lesion detected .
both the elevated suv and the tomodensitometric appearance were more in favor of a malignant process . a fine needle aspiration ( fna )
was performed after the positive pet / ct result to rule out a malignancy and was inconclusive . to avoid both , missing a malignant disease and unnecessary large surgical procedures , we opted for a minimally invasive surgical exploration guided by frozen section .
the different resection possibilities , tumorectomy or partial esogastrectomy with merendino reconstruction or radical esophagogastrectomy , were comprehensively explained to the patient .
laparoscopic exploration of the abdominal cavity showed no gross anomalies except the adhesions from the previous splenectomy .
liberation of the abdominal esophagus and progressive dissection of the thoracic esophagus revealed a multi - lobulated lesion adherent to the esophagus .
the mass was then extracted in an endo - bag via a small midline laparotomy using the superior part of the existing splenectomy incision , intraoperative histo - pathological examination revealed a benign esophageal leiomyoma .
final histo - pathological result showed macroscopically a 5    3    5    3  cm white homogenous mass with a lobulated aspect .
microscopically , the resected specimen showed intercrossing smooth muscle fibers with no nuclear anomalies and minimal inflammatory focal infiltration ; findings characteristic of a leiomyoma ( figs . 4 and 5 ) .
immunohistochemical examination also demonstrated negative reactivity for cd117 ( c - kit proto - oncogene product ) , cd34 , mib-1 , and glucose transporter-1 ( glut-1 ) along with the absence of mutation in c - kit or platelet - derived growth factor receptor , allowing us to rule out a gastrointestinal stromal tumor .
preoperative diagnosis of leiomyoma relies on many imaging techniques such as endoscopic ultrasonography that shows a homogeneous and hypoechoic lesion with clear margin .
ct scan ideally completes the preoperative evaluation of the patients , revealing in most cases a mass originating from esophagus without lymphadenopathies . in our case ,
some argue that it can render enucleation more difficult also fna entails the risk of esophageal leak or fistula with a risk of potential mediastinitis .
positron emission tomography ( pet ) with a labeled glucose analog , f18-fluorodeoxyglucose ( fdg ) is a valuable diagnostic tool that is widely used to survey malignant and inflammatory disease .
fdg - pet is an imaging modality for abnormality of function or metabolism in tissue and organs , which usually precedes anatomic change .
fdg accumulation has already been described in cases of uterine leiomyomas and in patients with esophageal and genital leiomyomatosis .
abnormal fdg accumulation in the esophagus can be explained by many non - oncological inflammatory conditions such as : gastro - esophageal reflux , barrett esophagus , acanthosis and infection . it would be wise to correlate an incidental fdg uptake with ct - scan findings in the gastro - esophageal junction . to our knowledge
, there have been 4 reports ( 5 cases ) of positive fdg - pet in the case of isolated benign lower esophageal leiomyoma .
the 2 cases reported at leuven were excised via a left thoracotomy [ table 1 ] . about 0.2% of leiomyomas show a malignant transformation to leiomyosarcoma .
however in our case , the suspicion of malignancy following chest ct findings and the fdg uptake on the pet scanner imposed a surgical option . with the finding of esophageal leiomyoma on frozen section exam ,
the minimally invasive approach versus the open one offers considerable advantages including reduced pain , better respiratory function , shorter hospital stay , faster return to regular activities , and esthetic of the surgical wound .
a high index of suspicion is demanded when dealing with positive fdg - pet / ct of the lower esophagus .
one should always take into account the macroscopic aspect as well as the results of the various imaging techniques available such as endoscopy , ultrasonography , ct or mri , laparoscopy and frozen section examination .
when dealing with an asymptomatic submucosal esophageal lesion with an abnormally increased uptake on pet / ctfdg scanner , this paper indicates that integrating all results of different imaging techniques does not allow an accurate diagnosis and an exploratory minimally invasive approach combined with a frozen section examination can potentially avoid excessive morbid surgical resections and particularly an underestimation of a malignant disease .
 written informed consent was obtained from the patient for publication of this case report and accompanying images .
a copy of the written consent is available for review by the editor - in - chief of this journal on request 
patrick flamen provided expertise in the field of nuclear medicine , and issam el nakadi also helped in patient contact and correction of the manuscript.key learning pointsminimal invasive approach combined with a frozen section can avoid excessive surgical resection and underestimation of malignant disease in positive pet / ctfdg submucosal esophageal lesion .
key learning pointsminimal invasive approach combined with a frozen section can avoid excessive surgical resection and underestimation of malignant disease in positive pet / ctfdg submucosal esophageal lesion .
minimal invasive approach combined with a frozen section can avoid excessive surgical resection and underestimation of malignant disease in positive pet / ctfdg submucosal esophageal lesion .
introductionleiomyoma is the most common benign tumor of the esophagus ( 6780% ) , it represents 0.41% of all esophageal tumors.presentation of casean incidentally discovered gastro - esophageal submucosal tumor was found to have increased fluorine-18-fluorodeoxyglucose ( fdg ) uptake on positron emission computed tomography ( pet / ct ) . 
 after laparoscopic surgical exploration and local enucleation the tumor turned out to be a benign esophageal leiomyoma.discussionthere are few reports of esophageal leiomyomas with a positive uptake on ( pet / ct ) and even fewer adopting our combination of a minimally invasive approach and frozen section examination as a management plan . 
 our approach avoided excessive morbid surgical resections and underestimation of a malignant disease.conclusionwe report this case hoping to expand the existing literature on the topic and to highlight the limitations of pet / ct in guiding the diagnosis and subsequently the management of esophageal submucosal tumors .