when treating pulmonary cancer complicated by interstitial pneumonia , it is critical to determine whether or not surgery is indicated . furthermore , the greatest problem when considering treatment for pulmonary cancer complicated by interstitial pneumonia is acute exacerbation , which presents an added risk in cases of surgery , anti - cancer drug treatment and radiotherapy . at present , radiotherapy and many anti - cancer drugs are prohibited as treatments for interstitial combined pulmonary cancer . as such , in cases of pulmonary cancer complicated by interstitial pneumonia , surgery is the only treatment that offers hope of a cure . in cases such as those in this study , where multiple nodules are found in other lung lobes , the authors consider how to assess the surgical indications for pulmonary cancer complicated by interstitial pneumonia , and whether determination is possible using imaging diagnosis alone . the authors report their experience of two cases of pulmonary cancer complicated by interstitial pneumonia in which multiple lung nodes were identified by proactive thoracoscopy , and were subjected to simultaneous curative surgery . the patient was a 76-year - old man in whom abnormal shadows were observed on a chest x - ray examination . he had a smoking history of 20 cigarettes per day for the past 46 years . auscultation of the chest resulted in the discovery of fine crackle sounds on both upper dorsal sides . blood biochemistry tests showed kl-6 : 622  u / ml , spd : 79.4  ng / ml , ldh : 215 iu / l , cea : 6.9  ng / ml , scc : 1.8  ng / ml , and cyfra : 4.0  ng / ml . blood gas analysis showed ph 7.419 , pco2 : 36.2  mmhg , and po2 : 71.6  mmhg , so2 : 93.9% . respiratory function testing demonstrated vc : 3.27  l , % vc : 111 , fev1 : 2.70 , % fev1 : 135 , and fev% : 82.8 . a chest x - ray examination showed a shadow with pale nodules measuring 20  mm in size with unclear margins in the left upper lung . a chest contrast ct examination indicated a node shadow measuring 19  mm in size in the left upper lobe s3 . both lower lobes had five nodules measuring from 6 to 12  mm in size . bronchoscopic examination including exfoliative cytodiagnosis from the b3c area resulted in a positive finding for non - small cell lung cancer ( nsclc ) . based on the findings of the above examinations , the patient was diagnosed as having pulmonary cancer complicated by interstitial pneumonia , ct1an0m0 , stage i a or ct4n0m0 , stage iii b. in order to determine the surgical indications , nodules from the left lung lower lobe were thoracoscopically biopsied and a swift diagnosis was thus obtained during surgery , based on the policy that if the findings did not indicate lung metastasis , curative surgery would be performed ; whereas , if they did indicate metastasis , surgery would not be performed . thoracoscopic observations of the lungs confirmed that the intrapulmonary lymph nodes were located directly below the lower lobe pleura . the nodules observed on ct images were biopsied after s9 pulmonary wedge resection , and were immediately examined to afford a swift diagnosis ; which showed that they were intrapulmonary lymph nodes with no malignancy . upper division segmentectomy of the left lung and mediastinal lymph node dissection were subsequently performed . the post - surgical progress was good , with the patient leaving the hospital eight days after surgery . at 25 months following surgery he had a smoking history of 20 cigarettes per day for the past 43 years . regarding his family history , his father had suffered from pulmonary fibrosis , and his mother had a history of stomach cancer and stroke . chest auscultation revealed the presence of bilateral fine crackle sounds on the upper dorsal sides . blood biochemistry findings indicated kl-6 : 832  u / ml , spd : 189  ng / ml , ldh : 228 iu / ml , cea : 5.2  mg / ml , scc : 1.4  ng / ml , and cyfra : 1.8  ng / ml . blood gas analysis showed ph 7.453 , pco2 : 39.0  mmhg , po2 : 98.9  mmhg , and so2 : 97.2% . respiratory function testing indicated vc : 4.20 , % vc : 119.3 , fev1 : 2.96 , % fev1:106 , fev% : 72.3 , and % dlco : 129.7 . a chest x - ray examination showed increasing density in the area overlapping the pulmonary artery in the right lung . chest contrast ct examination demonstrated the presence of a shadow measuring 29  mm in size and the presence of nodules with a cavity located directly below the right lung lower lobe s6 pleura . within the same lung lobe , seven nodule shadows measuring between 2 and 3  mm in size both sides indicated reticular shadows in the lower dorsal lobe , with interstitial lesions ( fig . based on the above findings , the patient was diagnosed as having pulmonary cancer complicated by interstitial pneumonia , ct2an1m0 , stage ii a , or ct4n1mo , stage iii b. in order to determine the surgical indications , the right s10 nodules were biopsied thoracoscopically , thus affording a swift diagnosis during surgery , based on the policy that if the findings did not indicate lung metastasis , curative surgery would be performed ; whereas , if they did indicate lung metastasis , surgery would not be performed . thoracoscopic observation of the lungs revealed the presence of black nodules directly below the lower pleura , leading to the determination of intrapulmonary lymph nodes . the s10 nodes depicted in the ct image also led to the diagnosis of an intrapulmonary lymph node , and consequently , biopsy was not performed . middle and lower lobectomy of the right lung and mediastinal lymph node dissection were subsequently performed . the ultimate pathological diagnosis was squamous cell carcinoma , pt2an1n0 , pstage ii a. a s10 node lung lymph tissue specimen showed no malignancy ( fig . thereafter , the patient made good progress and left the hospital eight days after surgery . he did not undergo any chemotherapy after surgery . at 28 months after undergoing surgery , the patient is alive and has had no recurrence . the patient was a 76-year - old man in whom abnormal shadows were observed on a chest x - ray examination . he had a smoking history of 20 cigarettes per day for the past 46 years . auscultation of the chest resulted in the discovery of fine crackle sounds on both upper dorsal sides . blood biochemistry tests showed kl-6 : 622  u / ml , spd : 79.4  ng / ml , ldh : 215 iu / l , cea : 6.9  ng / ml , scc : 1.8  ng / ml , and cyfra : 4.0  ng / ml . blood gas analysis showed ph 7.419 , pco2 : 36.2  mmhg , and po2 : 71.6  mmhg , so2 : 93.9% . respiratory function testing demonstrated vc : 3.27  l , % vc : 111 , fev1 : 2.70 , % fev1 : 135 , and fev% : 82.8 . a chest x - ray examination showed a shadow with pale nodules measuring 20  mm in size with unclear margins in the left upper lung . a chest contrast ct examination indicated a node shadow measuring 19  mm in size in the left upper lobe s3 . both lower lobes had five nodules measuring from 6 to 12  mm in size . bronchoscopic examination including exfoliative cytodiagnosis from the b3c area resulted in a positive finding for non - small cell lung cancer ( nsclc ) . based on the findings of the above examinations , the patient was diagnosed as having pulmonary cancer complicated by interstitial pneumonia , ct1an0m0 , stage i a or ct4n0m0 , stage iii b. in order to determine the surgical indications , nodules from the left lung lower lobe were thoracoscopically biopsied and a swift diagnosis was thus obtained during surgery , based on the policy that if the findings did not indicate lung metastasis , curative surgery would be performed ; whereas , if they did indicate metastasis , surgery would not be performed . thoracoscopic observations of the lungs confirmed that the intrapulmonary lymph nodes were located directly below the lower lobe pleura . the nodules observed on ct images were biopsied after s9 pulmonary wedge resection , and were immediately examined to afford a swift diagnosis ; which showed that they were intrapulmonary lymph nodes with no malignancy . upper division segmentectomy of the left lung and mediastinal lymph node dissection were subsequently performed . the post - surgical progress was good , with the patient leaving the hospital eight days after surgery . at 25 months following surgery he had a smoking history of 20 cigarettes per day for the past 43 years . regarding his family history , his father had suffered from pulmonary fibrosis , and his mother had a history of stomach cancer and stroke . chest auscultation revealed the presence of bilateral fine crackle sounds on the upper dorsal sides . blood biochemistry findings indicated kl-6 : 832  u / ml , spd : 189  ng / ml , ldh : 228 iu / ml , cea : 5.2  mg / ml , scc : 1.4  ng / ml , and cyfra : 1.8  ng / ml . blood gas analysis showed ph 7.453 , pco2 : 39.0  mmhg , po2 : 98.9  mmhg , and so2 : 97.2% . respiratory function testing indicated vc : 4.20 , % vc : 119.3 , fev1 : 2.96 , % fev1:106 , fev% : 72.3 , and % dlco : 129.7 . a chest x - ray examination showed increasing density in the area overlapping the pulmonary artery in the right lung . chest contrast ct examination demonstrated the presence of a shadow measuring 29  mm in size and the presence of nodules with a cavity located directly below the right lung lower lobe s6 pleura . within the same lung lobe , seven nodule shadows measuring between 2 and 3  mm in size both sides indicated reticular shadows in the lower dorsal lobe , with interstitial lesions ( fig . based on the above findings , the patient was diagnosed as having pulmonary cancer complicated by interstitial pneumonia , ct2an1m0 , stage ii a , or ct4n1mo , stage iii b. in order to determine the surgical indications , the right s10 nodules were biopsied thoracoscopically , thus affording a swift diagnosis during surgery , based on the policy that if the findings did not indicate lung metastasis , curative surgery would be performed ; whereas , if they did indicate lung metastasis , surgery would not be performed . thoracoscopic observation of the lungs revealed the presence of black nodules directly below the lower pleura , leading to the determination of intrapulmonary lymph nodes . the s10 nodes depicted in the ct image also led to the diagnosis of an intrapulmonary lymph node , and consequently , biopsy was not performed . middle and lower lobectomy of the right lung and mediastinal lymph node dissection were subsequently performed . the ultimate pathological diagnosis was squamous cell carcinoma , pt2an1n0 , pstage ii a. a s10 node lung lymph tissue specimen showed no malignancy ( fig . thereafter , the patient made good progress and left the hospital eight days after surgery . he did not undergo any chemotherapy after surgery . at 28 months after undergoing surgery , the patient is alive and has had no recurrence . the increasing use of ct scans and improved image resolution has led to increased opportunities to discover nodule shadows . it has been reported that between 0 and 1% of nodules measuring less than 5  mm , and between 6 and 28% of nodules measuring 510  mm are malignant lesions , and consequently , it is necessary to be able to identify lung cancer and metastatic lung tumors , among other malignant conditions , . examined 26 cases of nodular shadows in the lungs , measuring 10  mm or less , in which resection was implemented , ultimately leading to 3 cases of primary lung cancer , 2 cases of metastatic lung tumor , 12 cases of intrapulmonary lymph nodes , 6 cases of lung hamartoma , and 3 cases of pulmonary tuberculosis , with intrapulmonary lymph nodes found to be the most common condition ( 46% ) , . the two cases in this study involved intrapulmonary lymph nodes , that were characteristic in that : ( 1 ) the border was sharp in most cases ; ( 2 ) iplns were found just under or up to several millimeters away from the pleura ; ( 3 ) more than one node was sometimes observed ; ( 4 ) they could cause pleural indentations ; and ( 5 ) the border might be rough similar to that of lung cancer . furthermore , fellow et al . and kradin et al . studied intrapulmonary lymph nodes that were confirmed during open - chest biopsy , and reported that in many cases , they were between 5 and 10  mm in size , were multiple , and were present below the pleura in the lower lobe . in these cases , all the nodules were also present in the pleural region , and apart from one that measured 13  mm , all measured 10  mm or less . furthermore , the rate of positive testing for lung cancer in fdg / pet was high , 8791% , between 21 and 30  mm , but at 15  mm or smaller this fell to 7582% , indicating that malignancy can not be ruled out even if the test shows negative results . this supports that observing nodules , roughly 10  mm in size , in the pleural area in ct images , whether singular or multiple , means that the possibility of intrapulmonary lymph nodes needs to be considered . as a result , transbronchial biopsy and needle biopsy using a ct guide have low accuracy rates for lesions measuring 1  cm or less , and consequently , it is necessary to implement thoracoscopic surgery , which offers the least invasive method , . in case 1 , the largest nodule on the left lower lobe , which measured 13  mm , was resected from the lung area for diagnosis . in case 2 , the surface of the lung had multiple black nodule shadows , allowing visual diagnosis of intrapulmonary lymph nodes . in both cases , nodules also existed in the lung that were not subject to surgery ; however , these were all subpleural and measured less than 10  mm , and were diagnosed as intrapulmonary lymph nodes . the implementation of swift diagnoses during surgery allowed a reduction in the risk of interstitial pneumonia acute exacerbation , since it allowed the diagnosis of the nodules and curative surgery of the cancer in a single process . observation of subpleural nodules , roughly 10  mm in size , whether singular or multiple , means that the possibility of intrapulmonary lymph nodes needs to be considered , and if surgery is indicated , proactive diagnosis must be carried out . even in cases of pulmonary cancer complicated by interstitial pneumonia , it should be implemented without hesitation if surgery is indicated ,