Lung cancer differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aditya Ganti M.B.B.S. [2] , Eiman Ghaffarpasand, M.D. [3],

## Overview[edit | edit source]

Lung cancer must be differentiated from other conditions that cause hemoptysis, cough, dyspnea, wheezing, chest pain, dysphonia, dysphagia, unexplained weight loss, unexplained loss of appetite, and fatigue. These conditions include pneumonia, bronchitis, metastatic cancer from a non-thoracic primary site, infectious granuloma, pulmonary tuberculosis, tracheal tumors, and a thyroid mass.

## Differentiating Lung Cancer from Other Diseases[edit | edit source]

### The following table summarizes the differentiation of various lung tumors based on histological and topographical features:[1][edit | edit source]

Abrevations:

HPV: human papillomavirus; CEA: Carcino embryogenic antigen; TTF1: Thyroid transcription factor-1; EMA: Epithelial membrane antigen; CK: Cyto keratin; CD: Cluster differentiation; NCAM: Neural Cell Differentiation Molecule;

MMP's: Mettaloprotineases matrix ; GFAP: Glial fibrocilliary acid protein

Benign Lung Tumors[2]
Benign lung tumor  | Risk/Epidemiology  | Pleuripotent cells  | Topography  | Gross  | Histology  | Immunohistochemistry  | Imaging  | Metastasis
Papilloma[3] | Squamous cell papilloma |

* HPV 6 and 11
* Men
* Median age of diagnosis is 54 years

* Epithelial cells

* Endobronchial

* Cauliflower-like lesions
* Tan-white soft to semifirm protrutions

* Loose fibrovascular core
* Stratified squamous epithelium
* Acanthosis
* Binucleate forms and perinuclear halos
* Koilocytosis

* N/A

* Well circumscribed
* Homogenous
* Non-calcified
* Solitary mass

* N/A

Glandular papilloma |

* Rare
* Mean age of diagnosis is 68 years

* Goblet cells of respiratory epithelium

* Endobronchial

* White to tan endobronchial polyps that measure from 0.7-1.5 cm

* Thick arborizing stromal stalks
* Thin-walled blood vessels
* Non-ciliated or ciliated epithelium

* N/A

* Well circumscribed
* Homogenous
* Non-calcified
* Solitary mass

* N/A

Adenoma[4] | Alveolar adenoma |

* Mean age of diagnosis is 53 years
* Female predominance

* Alveolar pneumocytes
* Septal mesenchyme

* All lung lobes
* Lower lobes
* Hilar

* 0.7-6.0 cm
* Well demarcated smooth
* Lobulated, multicystic
* Soft to firm
* Pale yellow to tan cut surfaces

* Non-encapsulated
* Multicystic masses
* Cuboidal cell linning
* Squamous metaplasia
* Myxoid and collagenous interstitium

* Keratin
* CEA
* Surfactant protein
* TTF-1
* Actin

* Well circumscribed
* Homogenous
* Non-calcified
* Solitary mass

* N/A

Papillary adenoma[5] |

* Mean age of diagnosis is 32 years
* Male predominance

* Bronchioloalveolar cell

* No lobar predilection
* Involves alveolar parenchyma

* Well defined
* Encapsulated
* Soft, spongy to firm mass
* Granular gray white/ brown
* 1.0- 4.0 cm

* Infiltration
* Papillary growth pattern
* Fibrovascular cores
* Cuboidal to columnar epithelial linning
* Cilitated and oxyphilic cells
* Occasional eosinophilic intranuclear inclusions

* Cytokeratin
* Clara cell protein
* TTF-1
* Surfactant apoprotein
* CEA

* Incidental finding

* N/A

Mucinous cystadenoma |

* No sex predilection
* Mean age of diagnosis is 52 years

* Mucus glands of the bronchus

* Central

* White-pink to tan
* Smooth and shiny tumors
* Gelatinous mucoid solid core
* 0.7-7.5 cm

* Numerous mucin-filled cystic spaces
* Non-dilated microacini, glands, tubules and papillae

* EMA
* Cytokeratins
* CEA

* Coin lesion
* Air-meniscus sign

* N/A

Malignant Lung Tumors[6]
Variants of lung carcinoma  | Risk Factors/Epidemiology  | Pleuripotent cell  | Topography  | Gross  | Histology  | Immunohistochemistry  | Imaging  | Metastasis
Squamous cell carcinoma (SCC)[7] | Papillary |

* Cigarette smokers
* Arsenic

* Epithelial cells

* Central

* White or grey lesions
* Focal carbon pigment deposits
* Cavitations
* Intraluminal polypoid masses
* Infiltration

* Exophytic
* Intra-epithelial
* Without invasion

* Keratin
* Cytokeratins
* CEA
* Thyroid transcription factor-1 (TTF-1)

* Lobar or entire lung collapse
* Shift of the mediastinum to the ipsilateral side
* Hilar, perihilar or mediastinal masses

* Liver
* Breast
* Bone

Clear cell |

* Cells with clear cytoplasm

Basaloid |

* Peripheral palisading of nuclei.
* Poor differentiation

Small cell carcinoma[8] |

* Smoking
* Radon exposure

* Bronchial precursor cell

* Peripheral

* White-tan, soft, friable perihilar masses
* Extensive necrosis
* 5% peripheral coin lesions

* Sheet-like growth
* Nesting
* Trabeculae
* Peripheral palisading
* Rosette formation
* High mitotic rate

* CD56
* Chromogranin
* Synaptophysin
* TTF-1

* Hilar or perihilar masses
* Mediastinal lymphadenopathy
* Lobar collapse

* Bone marrow
* Liver

Adenocarcinoma[9][10][11] | Acinar adenocarcinoma |

* Smoking

* Columnar cells of bronchioles

* Peripheral

* Single or multiple lesions
* Different in size
* Peripheral distribution
* Gray-white central fibrosis
* Pleural puckering
* Anthracotic pigmentation
* Necrosis
* Cavitation
* Hemorrhage
* Lobulated or ill defined edges

* Irregular-shaped glands
* Malignant cells:
* Hyperchromatic nuclei
* Fibroblastic stroma

* Epithelial markers
* CEA
* CK7
* TTF-1

* Peripheral nodules under 4.0 cm in size
* Central location as a hilar or perihilar mass
* Rarely show cavitations.
* Hilar adenopathy
* Adenocarcinomas account for the majority of small peripheral cancers identified radiologically.

| Aerogenous spread is characteristic

* Brain
* Bone
* Adrenal glands
* Liver
* Kidney
* Gastrointestinal Tract

Papillary adenocarcinoma |

* Papillae
* Necrosis
* Surrounding invasion
* Cuboidal to columnar epithelial linning
* Mucinous or non-mucinous

Bronchio-alveolar carcinoma | Non-mucinous |

* Clara cells
* Type II cells

Mucinous |

* Low grade differentiation
* Composed of:
* Tall columnar cells
* Basal nuclei
* Pale cytoplasm resembling goblet cells
* Varying amounts of cytoplasmic mucin
* Cytologic atypia

Mixed non-mucinous and mucinous or indeterminate |

* Mixed type of cells
* Low to high grade differentiated cells.

Solid adenocarcinoma with mucin production | Fetal adenocarcinoma |

* Consists glandular elements:
* Tubules of glycogen-rich
* Non-ciliated cells
* Subnuclear and supranuclear glycogen vacuoles
* Rounded morules of polygonal cells with abundant eosinophilic and finely granular cytoplasm

Mucinous (“colloid”) carcinoma |

* Dissecting pools of mucin containing neoplastic cells

Mucinous cystadenocarcinoma |

* Partial fibrous tissue capsule
* Central cystic change with mucin pooling
* Neoplastic mucinous epithelium grows along alveolar walls

Signet ring adenocarcinoma |

* Focal
* Cells with nuclei displaced to sides
* Components of other cells are present.

Clear cell adenocarcinoma |

* Clear cells with no nuclei

Variants of lung carcinoma  | Risk Factors/Epidemiology  | Pleuripotent cell  | Topography  | Gross  | Histology  | Immunohistochemistry  | Imaging  | Metastasis
Large cell carcinoma[12] | Basaloid large cell carcinoma of the lung |

* Approximately 10% of lung cancers
* Smoking

* Neuro endocrine cells
* Suprabasal bronchial cells

* Peripheral masses
* Bronchi

* Soft, pink-tan tumor

* Necrosis and occasional hemorrhage
* Cavitations
* Exophytic bronchial growth

* Invasive growth pattern
* Peripheral palisading
* Small, monomorphic, cuboidal fusiform

* Chromogranin
* Synaptophysin
* CD56
* Cytokeratin

* Large, peripheral masses

* Pleura
* Liver
* Bone
* Brain
* Abdominal lymph nodes
* Pericardium

Clear cell carcinoma of the lung |

* Clear cells

Lymphoepithelioma-like carcinoma of the lung |

* Syncytial growth pattern
* Eosinophilic nucleoli
* Lymphocytic infiltration
* Invasive
* Amyloid deposition

Large-cell lung carcinoma with rhabdoid phenotype |

* Eosinophilic cytoplasmic globules
* Small foci of adenocarcinoma
* Eosinophilic inclusions

Mixed type |

* Mixture of:
* Adenocarcinoma
* Squamous cell carcinoma
* Giant cell carcinoma
* Spindle cell carcinoma

Variants of lung carcinoma  | Risk Factors/Epidemiology  | Pleuripotent cell  | Topography  | Gross  | Histology  | Immunohistochemistry  | Imaging  | Metastasis
Sarcomatoid carcinoma[13] | Carcinosarcoma |

* Accounts for only 0.3-1.3% of all lung malignancies
* Mean age at diagnosis is 60 years
* Tobacco smoking
* Asbestos exposure

* Undifferentiated epithelial cells

* Central or peripheral
* Upper lobes

* > 5 cm
* Well circumscribed
* Grey, yellow or tan creamy, gritty,
* Mucoid and/or hemorrhagic with significant necrosis
* Sessile or pedunculated
* Infiltrative

* Biphasic
* Mixture of carcinomatous and sarcomatous cells

* Keratin
* S-100

* No specific imaging features

* Aggressive tumor
* Esophagus, jejunum, and rectum
* Kidney

Spindle cell carcinoma |

* Only spindle shaped tumor cells
* Lymphoplasmacytic infiltrates

* Keratin
* EMA
* Cytokeratin
* Vimentin
* CEA
* TTF-1

Giant cell carcinoma |

* Multi- and/or mononucleated tumor giant cells

Pleomorphic carcinoma |

* Poorly differentiated
* Mixture of spindle cells and/or giant cells
* Fibrous or myxoid stroma

Pulmonary blastoma |

* Biphasic
* Mixture of epithelial and mesenchymal stroma

* Keratin
* EMA
* CEA
* Chromogranin A

Variants of lung carcinoma  | Risk Factors/Epidemiology  | Pleuripotent cell  | Topography  | Gross  | Histology  | Immunohistochemistry  | Imaging  | Metastasis
Carcinoid tumor[14] | Typical carcinoid

Atypical carcinoid

* Most common in males
* Mean age of diagnosis 45

* Neuroendocrine cells of lung

* Typical carcinoids are throughout the lungs

* Atypical carcinoid is more commonly peripheral

* Firm, well demarcated, tan to yellow tumors

* Uniform polygonal cells
* Nuclear atypia
* Pleomorphism
* The most common patterns are the organoid and trabecular
* Highly vascularized fibrovascular stroma
* Focal necrosis

* Cytokeratin
* Chromogranin
* Synaptophysin
* CD57
* CD56
* S-100 protein

* Well defined pulmonary nodules
* Calcifications is often seen.
* Intense contrast enhancement

* Liver
* Bone

Salivary gland tumors[15] | Mucoepidermoid carcinoma |

* Most patients presents in the third and fourth decade
* Constitutes of less than 1% tumor
* No association with cigarette smoking or other risk factors

* Primitive cells of tracheobronchial origin

* Bronchial glands

* Ranging in size from 0.5-6 cm
* Soft, polypoid, and pink-tan in colour
* High-grade lesions are infiltrative

* Exophytic endobronchial growth
* Surface epithelium lacking changes of in-situ carcinoma
* Absence of individual cell keratinization
* Transitional areas to low grade mucoepidermoid carcinoma

* GFAP

* Well-circumscribed oval or lobulated mass
* Calcifications
* Post-obstructive pneumonic infiltrates

* Rare
* Liver
* Bones
* Adrenal gland
* Brain

Adenoid cystic carcinoma |

* Constitutes less than 1% of all lung tumors
* Most commonly seen in fourth and fifth decades of life

* Primitive cells of tracheobronchial origin

* Trachea

* Gray-white or tan polypoid lesions

* Size ranges from 1–4 cm

* Infiltrative margins

* Invades other cell layers
* Heterogeneous cellularity
* Cribriform pattern
* Perineural invasion

* Immunoperoxidase
* Cytokeratin
* Vimentin
* Actin
* Calponin
* S-100 protein
* p53
* GFAP

* Well circumscribed
* Nodule

* Liver
* Brain
* Bone
* Spleen
* Kidney
* Adrenal glands

Epithelial-myoepithelial carcinoma |

* Age ranges from 33 to 71 years
* No association with smoking

* Myoepithelial cells

* Endobronchial

* Solid to gelatinous in texture
* White to gray in colour

* Myoepithelial cells
* Dual layer of cells lining ducts
* Low mitotic activity

* MNF116
* EMA
* SMA and S-100

* Reflects airway obstruction

* Breast

Variants of lung carcinoma  | Risk Factors/Epidemiology  | Pleuripotent cell  | Topography  | Gross  | Histology  | Immunohistochemistry  | Imaging  | Metastasis
Preinvasive lesions[16] | Squamous carcinoma in situ |

* Most commonly seen in fifth or sixth decades
* Mostly seen in women

* Basal cells of squamous epithelium

* Bronchi

* Focal or multi-focal plaque-like greyish lesions
* Nonspecific erythema
* Even nodular or polypoid lesions

* Goblet cell hyperplasia

* Basal cell hyperplasia

* Squamous dysplasia

* Angiogenic squamous dysplasia

* Micropapillomatosis

* EGFR
* HER2/neu
* p53
* MCM2
* Ki-67
* Cytokeratin 5/6
* Bcl-2
* VEGF
* Folate binding protein
* p16

* Cauliflower like
* Mosaic pattern

* Liver
* Brain
* Bone
* Spleen

Atypical adenomatous hyperplasia |

* Surfactant apoprotein
* Clara cell specific 10kDd protein

* Pleura
* Upper lobes

* Multiple grey to yellow foci
* 1mm to 10mm in size

* Intranuclear inclusions
* Clara cells and type II pneumocytes
* Thickened alveolar walls
* Discontinuous lining of cells
* Moderate atypia
* Pseudopapillae

* CEA
* MMPs
* E-cadherin
* ß-catenin
* CD44v6
* TTF-1
* TP53

* Typically not visualized on radiographs
* Small non-solid nodules

* Ground-glass opacity

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia |

* Pulmonary neuroendocrine cells

* Endobronchial

* Early lesions are:
* Small, gray-white nodules
* Resembling ‘miliary bodies’
* Larger carcinoid tumors are:
* Firm
* Homogeneous
* Well-defined
* Grey or yellow-white masses

* Nodular aggregates
* Fibrosis due to proliferation
* Invade locally
* Fibrous stroma aggregates to form ‘tumorlets’.
* Carcinoids are tumorlets >5cm.

* Keratin
* CEA

* Mosaic pattern of air trapping
* Sometimes with nodules
* Thickened bronchial and bronchiolar walls

Variants of lung carcinoma  | Risk Factors/Epidemiology  | Pleuripotent cell  | Topography  | Gross  | Histology  | Immunohistochemistry  | Imaging  | Metastasis
Mesenchymal tumors[17] | Epithelioid haemangioendothelioma / Angiosarcoma |

* Caucasian
* 80% are women

* Endothelial cells

* Intravascular

* 0.3-2.0 cm circumscribed mass
* Gray-white or gray-tan firm tissue
* Yellow flecks
* Central calcifications
* Cut surface has a cartilaginous consistency

* Round to oval-shaped nodules
* Central sclerosis
* Hypocellular zone
* Peripheral cellular zone
* Calcifications
* Intranuclear cytoplasmic inclusions

* CD31
* CD34
* Factor VIII (von Willebrand factor)
* Cytokeratin

* Multiple
* Bilateral
* Small nodules
* 1-2 cm in size
* Can mimic pulmonary Langerhans’ cell histiocytosis.
* Calcifications

* Liver
* Bone
* Soft tissue

Pleuropulmonary blastoma |

* Most common in children
* Median age of diagnosis is 2 years

* Thoracic splanchnopleural mesenchyme

* Pleura
* Lung

* Purely cystic
* Thin-walled
* Rarely solid
* Firm to gelatinous
* Upto 15 cm

* Type I
* Purely cystic
* Lined by respiratory type epithelium
* Underneath malignant cells
* Type II
* Partial or complete overgrowth of the septal stroma
* Type III
* Mixed cells

* Vimentin
* S-100 protein

* Unilateral
* Localized airfilled cysts
* Septal thickening or an intracystic mass

* Brain
* Spinal cord
* Skeletal system
* Eyes
* Pancreas

Chondroma |

* Young women

* Chondrocytes
* Cartilaginous cells

* Peripheral lesions in lung
* Primary lesion seen in
* Stomach
* Bone
* Paraganglia

* Peripheral
* Solid lesions
* Calcified

* Capsulated lobules
* Hypocellular
* Features of malignancy are absent

* N/A

* Multiple
* Well circumscribed lesions
* “Pop-corn” calcifications

* Benign in nature

Congenital peribronchial myofibroblastic tumor |

* Rare
* Sporadic
* Complicated by
* Polyhydramnios
* Non-immune hydrops fetalis

* Spindle cells

* Along the bronchi

* 5-10 cm
* Well-circumscribed
* Non-encapsulated
* Smooth or multinodular surface
* The cut surface has a tann-grey to yellow-tan fleshy appearance
* Hemorrhage
* Necrosis

* Fascicles of spindle cells
* Bronchial invasion
* Peribronchial distribution
* Cystic foci of hemorrhage

* Vimentin

* Well circumscribed
* Opaque hemithorax
* Heterogeneous mass

* Rare

Diffuse pulmonary lymphangiomatosis |

* Children
* Young adults of both sexes

* Smooth muscle cells of lymphatic vessels

* Along the lymphatic distribution

* Prominence of the bronchovascular bundles along
* Pleura
* Interlobular pulmonary septa
* Mediastinum

* Anastomosing endothelial-lined cells along lymphatic routes

* Spindle cells
* Intra alveolar siderophages

* Vimentin

* Increased interstitial markings

* Thickening of the:
* Interlobular septa
* Fissures
* Central airways
* Pleura

* Skin
* Bone

Inflammatory myofibroblastic tumor |

* Previous viral infections
* HHV8
* Children

* Myofibroblastic cells

* Localized to bronchi

* Solitary

* Round rubbery masses

* Yellowish-gray discoloration
* Average size of 3.0 cm
* Non-encapculated
* Calcifications
* No local invasion

* Mixture of spindle cells
* Fibroblastic
* Myofibroblastic
* Arranged in fascicles
* Cytologic atypia
* Touton type giant cells
* Plasma cells
* Lymphoid follicles

* Vimentin
* Actin
* p80

* Solitary mass
* Regular borders
* Spiculated appearance
* Accompanied by
* Post-obstructive pneumonia
* Atelectasis

* Rare

Pulmonary artery sarcoma |

* Mean age of diagnosis is 49.3 years
* Commonly misdiagnosed as pulmonary embolism

* Mesenchymal cells of the intima
* Primitive cells of the bulbus cordi in the trunk of pulmonary artery

* Pulmonary trunk most commonly involving:
* Right pulmonary artery
* Left pulmonary artery
* Pulmonary valve
* Right ventricular outflow tract

* Mucoid or gelatinous clots filling vascular lumens
* The cut surface may show
* Firm fibrotic areas
* Bony/gritty or chondromyxoid foci
* Hemorrhage and necrosis are common in high-grade tumors

* Spindle cells in
* A myxoid background
* Collagenized stroma
* Recanalized thrombi

* Vimentin
* Osteopontin
* Factor VIII
* CD31
* CD34

* Findings overlap with those of chronic thromboembolic disease
* Decreased vascularity
* Heterogeneous soft tissue density
* Smooth vascular tapering

* Lung parenchyma
* Mediastinum

Pulmonary vein sarcoma |

* Most common in women
* Mean age of diagnosis is 49

* Smooth muscle

* Pulmonary vein

* Fleshy-tan tumor
* Can occlude the lumen of the involved vessel
* 3.0- 20.0 cm
* Invasion of wall of the vein

* Smooth muscle differentiation
* Moderate to highly cellular spindle cell neoplasms
* Epithelioid morphology

* Vimentin
* Desmin
* Actin
* Keratin

* N/A

### The following table summarizes the differentiation of lung cancer from other disease entities with similar presentation.[18][19][20][21][22][edit | edit source]

Disease  | Clinical features

Signs & symptoms

| Radiological Findings  | Characterstic feature

|
|
|

Fever  | Cough  | Hemoptysis  | Dyspnea  | Chest pain  | Weight loss  | Night sweats
High-grade  | Low grade  | Productive  | Dry
Acute Lung abscess  | \+  | \-  | \+  | \-  | \-  | \-  | \+  | \-  | - |

* Air fluid level

* Foul smelling sputum
* H/o of prior infection or hospitalization
* Associated with risk factors like aspiration and alcoholism

Malignancy

(primary lung cancer)

| \-  | \+  | \-  | \+  | \+  | \-  | \-  | \+  | \+  |

* Coin-shaped lesion
* Thick wall(>15mm)
* Ground glass opacities

* Long h/o smoking
* Elderly male or female
* Broncho-alveolar lavage positive for malignant cells
* CT guided biopsy is required for confirmation and differentiation

Pulmonary Tuberculosis | \+  | \-  | \+  | \-  | \+  | \-  | \-  | \-  | \+  |

* Cavitations in the upper lobe of the lung

* People in endemic at high risk
* Cough >2 weeks with hemoptysis
* Acid fast stain positive for mycobacteria

Necrotizing Pneumonia | \+  | \-  | \+  |  | \+  | \-  | \+  | \-  | \-  |

* Multiple cavitary lesions

* Acute life-threatening condition
* Complication of pneumonia or lung abscess
* Multiple organisms responsible
* Prompt treatment with antibiotics is required
* Blood culture positive for causative organism

Empyema  | \+  | \-  | \+  | \-  | \+  | \+  | \+  | \-  | \-  |

* Homogeneous consolidations

* Blood culture positive for the causative agent

Bronchiectasis | \-  | \-  | \+  | \-  | \+  | \-  | \-  | \-  | \-  |

* Linear lucencies
* Tram tracking appearance
* Clustered cysts

* Increased pulmonary markings
* Honeycombing
* Atelectasis

* CT confirms the diagnosis

Wegners granulomatosis | \-  | \-  | \+  |  | \+  | \+  | \-  | \-  | \-  |

* Pulmonary nodules
* Cavities
* Infiltrates

* Seen mostly in female age group of 40-55 years
* Traid of Upper , lower respiratory tract and kidney disease
* Biopsy of involved organ confirms granulomas

Sarcoidosis | \+  | \-  | \+  | \-  | \+  | \-  | \-  | \+  | \+  |

* Bilateral adenopathy
* Coarse reticular opacities

* More common in African-american females
* Restrictive lung disease
* Biposy findings: epithelioid,granulomas, schaumann, asteroid bodies.

Rheumatoid nodule | \-  | \-  | \-  | \-  | \-  | \+  | \-  | \+  | \-  |

* Pulmonary nodules
* Cavitations on the upper lobe of lung

* Rheumatoid arthritis
* Positive for RF and ACP

Langerhans cell Histiocytosis | \-  | \-  | \-  | \-  | \-  | \+  | \+  | \+  | \-  |

* Thin-walled cystic cavities

* Exclusively afflicts smokers
* Musculoskeletal and skin is involved
* Biopsy of the involved organ

Bronchiolitis obliterans | \-  | \-  | \+  | \-  | \+  | \+  | \+  | \-  | \-  |

* Patchy consolidation,

* Ground-glass opacities

* Nodules

* Biopsy

## References[edit | edit source]

1. ↑ Erasmus JJ, Connolly JE, McAdams HP, Roggli VL (2000). "Solitary pulmonary nodules: Part I. Morphologic evaluation for differentiation of benign and malignant lesions". Radiographics. 20 (1): 43–58. doi:10.1148/radiographics.20.1.g00ja0343. PMID 10682770.
2. ↑ Gümüştaş S, Inan N, Akansel G, Ciftçi E, Demirci A, Ozkara SK (June 2012). "Differentiation of malignant and benign lung lesions with diffusion-weighted MR imaging". Radiol Oncol. 46 (2): 106–13. doi:10.2478/v10019-012-0021-3. PMC 3472932. PMID 23077446.
3. ↑ Maxwell RJ, Gibbons JR, O'Hara MD (January 1985). "Solitary squamous papilloma of the bronchus". Thorax. 40 (1): 68–71. PMC 459982. PMID 3969658.
4. ↑ Shiota Y, Matsumoto H, Sasaki N, Taniyama K, Hashimoto S, Sueishi K (1998). "Solitary bronchioloalveolar adenoma of the lung". Respiration. 65 (6): 483–5. doi:10.1159/000029319. PMID 9817965.
5. ↑ Kanchustambham V, Saladi S, Patolia S, Mahmoud Assaf S, Stoeckel D (March 2017). "A Rare Case of a Benign Primary Pleomorphic Adenoma of the Lung". Cureus. 9 (3): e1069. doi:10.7759/cureus.1069. PMC 5375953. PMID 28409070.
6. ↑ Kelley LC, Puette M, Langheinrich KA, King B (November 1994). "Bovine pulmonary blastomas: histomorphologic description and immunohistochemistry". Vet. Pathol. 31 (6): 658–62. doi:10.1177/030098589403100605. PMID 7863581.
7. ↑ Roth E, Smidt D (January 1970). "[Studies on early ejaculate collection using electroejaculation in German improved land-swines and Goettinger miniature pigs]". Berl. Munch. Tierarztl. Wochenschr. (in German). 83 (1): 7–11. PMID 5528918.CS1 maint: Unrecognized language (link)
8. ↑ Jackman DM, Johnson BE (2005). "Small-cell lung cancer". Lancet. 366 (9494): 1385–96. doi:10.1016/S0140-6736(05)67569-1. PMID 16226617.
9. ↑ Mitchell, Richard Sheppard; Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson. "Chapter 13, box on morphology of adenocarcinoma". Robbins Basic Pathology (8th ed.). Philadelphia: Saunders. ISBN 1-4160-2973-7.CS1 maint: Multiple names: authors list (link)
10. ↑ Soda M, Choi YL, Enomoto M, Takada S, Yamashita Y, Ishikawa S; et al. (2007). "Identification of the transforming EML4-ALK fusion gene in non-small-cell lung cancer". Nature. 448 (7153): 561–6. doi:10.1038/nature05945. PMID 17625570.CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)
11. ↑ Adenocarcinoma of the lung. Librepathology 2015. http://librepathology.org/wiki/index.php/File:Adenocarcinoma_(3950819000).jpg
12. ↑ Rossi G, Mengoli MC, Cavazza A, Nicoli D, Barbareschi M, Cantaloni C, Papotti M, Tironi A, Graziano P, Paci M, Stefani A, Migaldi M, Sartori G, Pelosi G (January 2014). "Large cell carcinoma of the lung: clinically oriented classification integrating immunohistochemistry and molecular biology". Virchows Arch. 464 (1): 61–8. doi:10.1007/s00428-013-1501-6. PMID 24221342.
13. ↑ Huang SY, Shen SJ, Li XY (October 2013). "Pulmonary sarcomatoid carcinoma: a clinicopathologic study and prognostic analysis of 51 cases". World J Surg Oncol. 11: 252. doi:10.1186/1477-7819-11-252. PMC 3850921. PMID 24088577.
14. ↑ Dahabreh J, Stathopoulos GP, Koutantos J, Rigatos S (March 2009). "Lung carcinoid tumor biology: treatment and survival". Oncol. Rep. 21 (3): 757–60. PMID 19212636.
15. ↑ Elnayal A, Moran CA, Fox PS, Mawlawi O, Swisher SG, Marom EM (July 2013). "Primary salivary gland-type lung cancer: imaging and clinical predictors of outcome". AJR Am J Roentgenol. 201 (1): W57–63. doi:10.2214/AJR.12.9579. PMC 3767141. PMID 23789697.
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