a 60-year - old male was referred to the asan medical center for a nodule in the left lower lobe ( lll ) .
the nodule was incidentally detected during the preoperative evaluation of gallstone , for which he underwent laparoscopic cholecystectomy at an outside hospital three months prior to his presentation to us .
on his visit , he did not have any respiratory complaints such as productive cough or dyspnea .
further , the patient had been a non - smoker for 10 years although he used to smoke half a pack a day for 30 years before quitting .
we found that the patient 's physical examination was unremarkable except decreased breath sounds over the left lower lung field .
chest x - ray and computed tomography scan revealed a mass having the following dimensions : 20105 mm .
the mass obstructed the secondary bronchus entering into the lll , which resulted in a total collapse of lll ( fig .
1 ) . a flexible bronchoscopy showed an endobronchial mass filling the basal segments of the lll ( fig .
the patient underwent a left lower lobectomy via left posterolateral thoracotomy through the 5th intercostal space .
we divided the lll bronchus at the level of the left upper lobe spur and performed a left lower lobectomy .
the medial side of the left main bronchus was repaired using an interrupted anastomosis of 3 - 0 vicryl .
the resection margin of the bronchial stump was clear from the tumor on the frozen section .
immunohistochemical staining demonstrated the positivity for s-100 protein , and the ki-67 labeling index was low ( 1% ) , supporting the current diagnosis .
granular cell tumor ( gct ) , a rare benign neoplasm that most commonly occurs in the tongue , skin , subcutaneous tissue , and breast , was first described by abrikossoff in 1926 .
pulmonary gct , known to comprise 6% to 10% of all gtcs , was first reported by kramer in 1938 , and since then , less than 80 cases of gct arising in the lung have been reported in the english - language literature . in korea , seo et al .  
it was traditionally termed ' granular cell myoblastoma ' until the late 1980s after abrikossoff suggested that gct had a myogenic origin .
now , it is believed that gct has a neural cell origin , thus establishing the current nomenclature .
although it has been known that most pulmonary gcts behave in a benign fashion , our review of the literature suggests that they have no unique clinical features .
pulmonary gcts can be associated with synchronous extrapulmonary gcts occurring in various organs , such as the tongue , kidney , or esophagus .
pulmonary gcts may occur metachronously in a single lung and thus , can be multicentric in 10% to 20% of the patients , although a majority of the gcts tend to be solitary .
pulmonary gcts can be associated with other malignancies or infectious diseases such as tuberculosis or human immunodeficiency virus .
pulmonary gcts can be diagnosed at any age , but most cases of pulmonary gct present in the third or the fourth decade .
previous clinical series showed that there is no gender predilection , and gcts are equally distributed over both lungs with a predilection for the upper lobe .
however , another study found a slight predilection toward the left lung with a preference for the lower lobe , as presented in our case
. there are no commonly agreed risk factors , although the association of smoking with pulmonary gcts was hypothesized in some studies .
more than half of the gct patients are asymptomatic at the time of diagnosis , and respiratory symptoms such as cough , dyspnea , hemoptysis , and wheezing present as tumor erosion and bronchial obstruction progress due to the growth of the endobronchial mass . with the onset of the symptoms ,
the bronchial obstruction causes the suppuration and destruction of the lung parenchyma distal to the obstruction ; in this case , surgical resection is clearly indicated .
advocated bronchoscopic resection in asymptomatic patients with a tumor having a diameter of less than 8 mm , and van der maten et al .   suggested that endobronchial therapy be the primary treatment
however , bronchoscopic removal can not be a safe treatment option as it does not guarantee complete removal when gcts infiltrate through the entire bronchial wall , which is evidenced by the fact that the incidence of recurrence was as high as 54% after bronchoscopic removal .
in addition , although extremely rare , it is possible that pulmonary gcts can be malignant ; the first case of malignant pulmonary gct was reported in 2003 .
being relatively young at the time of diagnosis can be a factor that favors complete surgical resection . in this regard ,
we believe that adequate surgical removal should be the preferred treatment option for all patients among whom gcts are amenable to surgical resection . based on the size , location , and number of masses , a surgical option , including either segmentectomy , lobectomy with or without sleeve resection , or rarely pneumonectomy , can be chosen with a lower incidence of recurrence and long disease - free survival .
 we report a rare case of granular cell tumor arising in the left lower lobe ( lll ) bronchus with secondary obstructive change in a 60-year - old male . the patient was found to have a nodule in the lll on a computed tomography scan , three months prior to his presentation to the asan medical center . 
 bronchoscopic biopsies revealed a granular cell tumor . after undergoing lll lobectomy with bronchoplasty 
 , the patient has not experienced any tumor recurrence . 
CASE REPORT
DISCUSSION