Lung Masses¶
Chandler Montgomery
Background¶
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Definitions: lesion \< 3 cm = pulmonary nodule. Lesion > 3 cm = lung mass
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Pulmonary nodules are common and often benign, but presence of lung mass (>3cm) should prompt workup as chance of malignancy is high (>50%)
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For nodules, refer to the Fleischner Society guidelines (incidental nodules) or Lung-RADS (detected on lung cancer screening) for surveillance/management recommendations
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Note that in TN, prior histoplasmosis is a very common cause of pulmonary nodules
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Differential diagnosis:
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Malignant:
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Primary non-small cell lung cancer (NCSLC): adenocarcinoma, squamous cell (SCC), large cell carcinoma
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Metastatic: commonly melanoma, sarcoma, colon, breast, renal, testicular
- Often multiple nodules/masses (e.g., cannonball)
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Neuroendocrine: small cell lung cancer (SCLC), carcinoid, large cell neuroendocrine
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Infectious:
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Granulomatous: TB, non-TB mycobacterium, endemic fungal (histo, blasto, coccidio)
- May have component of calcification
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Abscess: Staph aureus, Klebsiella, anaerobes, polymicrobial (aspiration)
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Septic emboli, hydatid cyst, aspergilloma
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Other: hamartoma, AVM, pulmonary infarct, inflammatory nodule (GPA, RA), sarcoidosis
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Evaluation¶
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History: smoking, cough, hemoptysis, dyspnea, chest pain, weight loss, fevers, night sweats, hoarseness, bone pain, neuro deficits
- Lung cancer should always be considered in a patient with smoking history & new cough or hemoptysis
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Exam: cachexia, lymphadenopathy, bone pain, hepatomegaly, neuro deficits
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Imaging:
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CXR has poor sensitivity for lung nodules, may show large mass or malignant effusion
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CT chest (with contrast if possible - better evaluation of mediastinum/LNs)
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Review prior chest imaging to assess age and growth pattern of lesion(s)
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Benign features: small (sub-centimeter), calcified, fat attenuation, stable over 2 years, multiple nodules
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Concerning features: large, growth, spiculation, upper lobe location, thick-walled cavitation, mediastinal invasion
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Location- adenocarcinoma often more peripheral, SCC often more central, SCLC associated with massive LAD, mediastinal invasion, large hilar masses
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Look for paraneoplastic syndromes:
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SCLC: SIADH, Lambert-Eaton, Cushing’s syndrome
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SCC: hypercalcemia (PTHrP)
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Dermatomyositis, polymyositis, hypertrophic osteoarthropathy
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Staging/Diagnosis¶
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Imaging: CT chest (with contrast if possible)m CTAP w/contrast vs. PET/CT to assess for metastasis, consider MRI brain if clinical stage III or IV disease
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Biopsy: careful planning is key
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For metastatic disease, obtain tissue from least invasive site
- FNA or excision of palpable lymph node (cytology department, US-guided procedure, or EGS)
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If uncertain how to best obtain tissue, consult IR, interventional pulm, and/or oncology to discuss approach
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Surgical Bx: Wedge resection/lobectomy often preferred if solitary nodule amenable to both diagnostic and therapeutic resection in good surgical candidate
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Bronchoscopy with EBUS (endobronchial US) often used to obtain biopsy of mediastinal tissue or central/peri-bronchial lesion
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Trans-thoracic needle aspiration (TTNA): peripheral lesions not amenable to bronchoscopy
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Management¶
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Planning is complex, usually discussed at multidisciplinary tumor board
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NSCLC
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Stage I/II: surgical resection ± adjuvant chemotherapy
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Stage III: more complex requiring multidisciplinary approach
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Stage IV: chemo ± targeted therapy depending on PD-L1 expression, presence of driver mutations for EGFR, ALK, ROS-1, BRAF, MET, RET, others
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SCLC: usually widely metastatic at time of diagnosis, treated with systemic chemo/radiation