primary tumors of the trachea are rare and account for 0.1% of all malignancies . in adults ,
approximately 90% of the primary tracheal tumors are malignant , whereas in children , the majority of these tumors are benign [ 2 , 3 ] . in a retrospective study by webb et al . , 55.4% of the patients were male and 77.3% of them were smokers .
the frequency of this rare disease has been estimated to be 0.10.4% of all malignancies , with an annual incidence of 2.6 new cases per million per year .
primary tracheal tumors can arise from the respiratory epithelium , salivary glands and mesenchymal structure of the trachea .
squamous cell carcinoma ( scc ) and adenoid cystic carcinoma ( acc ) make up about 71.6% of all adult primary tracheal tumors . the remaining portion ( 28.4% )
scc occurs predominantly in men in the sixth and seventh decades , whereas acc is equally distributed between the sexes and peaks in incidence in the fourth and fifth decades .
in contrast to acc , scc ( the most common type of tracheal tumors ) has a more aggressive course .
median survival time ranges from 6 to 14 months , and tumor disappearance is dependent on whether the primary lesion is resected .
sccs spread to the lymph nodes and 1020% of the patients will have distant metastasis at presentation .
carcinoids , lymphomas , granular cell tumors and small cell carcinomas have variable prognoses ; yet they seem to behave better than sccs , adenocarcinomas or sarcomas .
the majority of the tracheal neoplasms are primary in nature , and other primary sites that can metastasize to the trachea are the lung and esophagus , the latter being the most common .
patients with surgically resectable primary tracheal tumors have a better prognosis than those with tumors that can not be resected .
preoperative radiation therapy has been attempted in some patients , yet the most compelling evidence for adjuvant radiation therapy comes from postoperative cases .
the present study reports a rare case of primary tracheal malignancy treated with surgery and adjuvant radiation therapy .
our 60-year - old diabetic and hypertensive male patient had a 1-month history of cough associated with marked respiratory distress and occasional dyspnea in the right lateral lying position .
the patient consulted a chest physician and underwent bronchoscopy , which showed a polypoid growth in the trachea extending to the larynx ( fig .
a computed tomography ( ct ) scan revealed irregular soft tissue thickening in the region of the trachea extending up to the adjacent larynx with no soft tissue calcification , and there was no definite lymphadenopathy in the cervical region and no involvement of the underlying bone . a repeat ct scan of the neck ( fig .
2 ) showed evidence of an ill - defined , irregular , nodular , infiltrating soft tissue growth arising from the posterior tracheal wall , bridging the lumen and reaching up to the anterior wall , with an infiltration of about 2.2  1.8 cm .
the location was opposite the c7-d1 level involving the 5th or 6th tracheal ring , approximately 7 cm proximal to the carina with no significant evidence of cervical and mediastinal lymphadenopathy .
excision of the tracheal growth through a cervical transverse incision was performed , and a tracheostomy tube was inserted .
soon after surgery , the cough subsided and the patient attended square hospital , dhaka , bangladesh , for postoperative irradiation .
ninety - five percent of the planning target volume ( ptv ) covered 97.3% of the prescribed dose .
the minimum and maximum dose received by the ptv was 50.05 and 63.68 gy , respectively .
3 ) . three multileaf collimator fields ( left anterior oblique , right anterior oblique and posterior ) were used for three - dimensional conformal radiation therapy ( 3dcrt ) .
complete response was documented , and the patient is still alive without any evidence of disease during 30 months of follow - up .
primary malignant tumors of the trachea are uncommon , and therefore limited data supporting a standard management are available .
the vast majority of the primary tracheal tumors in adults are malignant and most of them usually diagnosed at a later stage , which is due to a delayed presentation of specific symptoms like cough , dyspnea and hemoptysis .
it is clear that patients who can be resected have a better prognosis than those who can not , prompting the recommendation of surgical resection for most primary tracheal tumors .
all resected patients need postsurgical irradiation , regardless of tumor burden , margin status , histology or nodal status .
grillo and mathisen   experienced a median survival of 34 months in scc and 118 months in acc patients who underwent a combined modality like surgery and radiation therapy .
attained a 61-month median survival using a combined surgery and radiation therapy in their study .
.   showed that 73% of the patients with a 5-year survival underwent radiation therapy postoperatively .
the role of external beam radiation therapy as an adjuvant to surgical resection is better established .
grillo and mathisen   advocated maximal ( 4,5006,500 cgy ) radiation therapy after scc and acc resection because of the close margins necessary for resection and the high likelihood of local recurrence .
modern ct - based 3dcrt or intensity - modulated radiation therapy theoretically allows higher and safer doses delivered to the trachea . for postoperative cases ,
all patients with this tumor in the postoperative or definitive setting should be treated with the 3dcrt technique .
an intraluminal boost technique after external beam radiation therapy may decrease the risk of late side effects .
there are many studies showing the benefit of postoperative irradiation therapy in primary tracheal malignancies such as sccs and accs .
however , little experience has been shared in the case of primary adenocarcinomas of the trachea , the tumor type described in our report .
the prognosis of patients with malignant tumors of the trachea remains gloomy , and long - term median survival of tracheal adenocarcinoma patients undergoing combined modalities is unknown to us .
primary adenocarcinoma of the trachea needs to be diagnosed at an early stage , and combined multimodal approaches may be explored to attain an extended median survival .
none of the authors has any conflicts of interest regarding the content of this article .
 primary adenocarcinoma of the trachea is extremely rare and a standard treatment does not exist due to nonavailability of evidence - based randomized control studies . this paper reports the case of a 60-year - old male , who presented with cough and occasional respiratory distress . 
 bronchoscopic examination and a computed tomography scan revealed a soft tissue mass in the trachea arising from the posterior tracheal wall . 
 cytological examination and immunochemistry confirmed primary adenocarcinoma of the trachea . 
 excision of the tumor followed by three - dimensional conformal radiation therapy was performed , and a dose of 56 gy was delivered to the primary site . 
 two and a half years after treatment , the patient has no clinical or radiological evidence of the disease , and no late complication has occurred . 