Lung Metastases-Lymphangitic Carcinomatosis

Epidemiology

  • Presence of lymphangitic pattern in patient with known malignancy: 70-80% probability of metastases being the cause

Etiology

(metastic adenocarcinomas account for 80% of lymphangitic lung metastasis cases)

  • Breast Cancer (see Breast Cancer, [[Breast Cancer]])
    • Autopsy Studies: 24% of breast cancer cases have lymphangitic lung mets
    • Mechanism: mediastinal or hilar node involvement with retrograde spread to lung lymphatics
  • Lung Cancer (see Lung Cancer, [[Lung Cancer]])
    • Mechanism: mediastinal or hilar node involvement with retrograde spread to lung lymphatics
  • Colon Cancer (see Colon Cancer, [[Colon Cancer]])
  • Gastric Cancer (see Gastric Cancer, [[Gastric Cancer]])
  • Testicular Cancer (see Testicular Cancer, [[Testicular Cancer]])
    • Mechanism: spread from distant nodes through lymphatics to lung lymphatics
  • Choriocarcinoma (see Choriocarcinoma, [[Choriocarcinoma]])
    • Mechanism: spread from distant nodes through lymphatics to lung lymphatics
  • Hodgkin’s Disease (see Hodgkin’s Disease, [[Hodgkins Disease]])
    • Mechanism: mediastinal or hilar node involvement with retrograde spread to lung lymphatics
  • Lymphoma (see Lymphoma, [[Lymphoma]])
    • Mechanism: mediastinal or hilar node involvement with retrograde spread to lung lymphatics
  • Prostate Cancer (see Prostate Cancer, [[Prostate Cancer]])
    • Lymphangitic pattern is probably most common pattern seen in prostate cancer mets to lung (this pattern seen in about 58% of cases)
    • Prostate cancer mets are rarely seen in absence of pre-existing lymph node or bone mets
  • Hepatocellular Carcinoma (see Hepatocellular Carcinoma, [[Hepatocellular Carcinoma]])
  • Pancreatic Cancer (see Pancreatic Cancer, [[Pancreatic Cancer]])
  • Thyroid Cancer (see Thyroid Cancer, [[Thyroid Cancer]])
  • Cervical Cancer (see Cervical Cancer, [[Cervical Cancer]])
  • Laryngeal Cancer (see Laryngeal Cancer, [[Laryngeal Cancer]])
  • Metastatic Adenocarcinoma of Unknown Primary

Physiology

  • Lymphangitic Carcinomatosis: diffuse infiltration and obstruction of pulmonary parenchymal lymphatic channels by tumor
    • Spread of malignant cells to lung lymphatics from:
      • Obstructed Lymph Nodes
      • Hematogenous Spread
      • Previously Seeded Pleural Fluid

Diagnosis

  • CXR
    • Diffuse reticulonodular infiltrates: often with linear markings radiating out from enlarged hilar or mediastinal nodes
    • Kerley B lines: thickened interlobular septa (seen at periphery of lung) due to pulmonary lymphatic obstruction
    • Pleural effusion (30-50% of cases)
      • Effusion occurs more commonly in breast cancer cases with lymphangitic lung mets than those with non-lymphangitic lung mets
  • HRCT
    • “Beaded chain” or “string of pearls” thickening of interlobular septa -> producing polygonal shapes (outlining the lobule)
      • Interlobular septa is usually irregular or nodular, but may be smoothly thickened
        • In contrast, in interstitial pulmonary edema, interlobular septa is usually smoothly thickened
      • Intervening parenchyma between the interlobular septa is typically normal (unlike in IPF, where it is usually distorted or honeycombed)
    • Centrilobular peribronchovascular thickening
    • Preservation of normal parenchymal architecture at the level of the secondary pulmonary lobule
    • Thickening of the fissures as a result of the involvement of the lymphatics concentrated in the subpleural interstitium
    • Peribronchovascular thickening
    • Lung Nodules
    • Pleural effusion (30-50% of cases)
      • Effusion occurs more commonly in breast cancer cases with lymphangitic lung mets than those with non-lymphangitic lung mets
    • Mediastinal and/or hilar lymphadenopathy (30-50% of cases)
    • Above findings may be unilateral or bilateral, focal or diffuse, and symmetrical or asymmetrical
      • Focal, unilateral lymphangitic disease occurs in 50% of cases
      • Focal, unilateral pattern is seen commonly in cases due to lung cancer
  • Sputum Cytology: may be used to diagnose lymphangitic mets
  • FOB
    • BAL is more sensitive than sputum cytology in diagnosis of lymphangitic mets
    • BAL may be diagnostic in lymphangitic carcinomatosis cases due to lymphoma
      • However, lymphocytosis >35% may also be seen in sarcoidosis, berylliosis, hypersensitivity pneumonitis, drug-induced ILD, LIP, breast cancer-related lymphangitic carcinmatosis, and infrequently, in lung cancer-related lymphangitic carcinmatosis cases)
      • Normal BAL lymphocyte percentage: <15%
      • BAL lymphocytosis is seen in about 50% of breast cancer cases with lymphangitic lung mets (Chest, 1992)
    • TBB: may be diagnostic
      • TBB use in this setting represents one of the few high yield uses of TBB in the diagnosis of interstitial lung disease
    • Cytology: immunohistochemical stains may be useful in identifying germ cell and breast cancers
  • PET Scan
    • 2005 Study: intensity of FDG uptake in the diseased lung is significantly greater than in the normal, contralateral lung [J Comput Assist Tomogr. May-Jun 2005;29(3):346-9]
    • 2006 Study: comparing PET with HRCT scans in 5 patients with lymphangitic carcinomatosis [Clin Nucl Med. Nov 2006;31(11):673-8]
      • FDG-PET scan activity distribution was identical to segmental, lobar, or diffuse areas of lymphangitic disease seen on HRCT
      • In segmental lymphangitic carcinmatosis, linear or hazy FDG uptake extending from the tumor may be seen

Clinical

  • Asymptomatic: often
  • Dyspnea (common)
  • Orthopnea (common)
  • Cough (common): due to mucosal edema associated with airway lymphatic infiltration
  • Chest tightness
  • Chest pain (late in course, with pleural involvement)
  • Pleural Effusion: occurs late in course

Prognosis

  • Presence of BAL Lymphocytosis (range: 15-45% of total cells): portends better prognosis in breast cancer cases with lymphangitic mets (Chest, 1992)

Treatment

  • Treat Underlying Malignancy
  • Steroids: may provide some symptomatic relief
    • May decrease inflammatory response to tumor cells in lung
  • Opiates: may relieve dyspnea
    • Nebulized Morphine Sulfate: may be useful
  • Oxygen: may relieve dyspnea
  • Antitussives: as required

References

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  • Endobronchial metastasis from stomach carcinoma. Monaldi Arch Chest Dis. Feb 2000;55(1):6-8
  • Imaging case of the month. Pulmonary lymphangitic carcinomatosis from adenocarcinoma of the prostate. Md Med J. Nov 1994;43(11):989-90
  • Case report: lymphangitic carcinomatosis from cervical carcinoma–an unusual presentation of diffuse interstitial lung disease. Am J Med Sci. Mar 1992;303(3):174-6
  • Recurrent squamous cell carcinoma of the cervix with pulmonary lymphangitic metastasis. Int J Gynaecol Obstet. Jan 1995;48(1):85-90
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  • Squamous cell carcinoma of the uterine cervix. Patterns of thoracic metastases. Invest Radiol. Dec 1995;30(12):724-9
  • Pulmonary lymphangitic sarcomatosis from cutaneous angiosarcoma: an unusual presentation of diffuse interstitial lung disease. Jpn J Clin Oncol. Jan 2000;30(1):37-9
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  • Bronchoalveolar lavage in malignancy. Semin Respir Crit Care Med. Oct 2007;28(5):534-45
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  • Comparison of high resolution CT findings of sarcoidosis, lymphoma, and lymphangitic carcinoma: is there any difference of involved interstitium?. J Comput Assist Tomogr. May-Jun 1999;23(3):374-9
  • Specific diagnosis by CT and HRCT in six chronic lung diseases. Comput Med Imaging Graph. Jul-Aug 1992;16(4):277-82
  • The ‘fragmented’ scintigraphic lung pattern in pulmonary lymphangitic carcinomatosis secondary to breast cancer. Respiration. 1998;65(5):406-10
  • Unusual appearance of thromboembolism on perfusion lung imaging. Clin Nucl Med. Sep 1999;24(9):684-6
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  • Pulmonary microvascular cytology in the diagnosis of lymphangitic carcinomatosis. N Engl J Med. Jul 13 1989;321(2):71-6
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  • High-resolution CT of the lungs. Am Fam Physician. Sep 1 1993;48(3):493-8
  • Unusual thoracic CT manifestations of osteosarcoma: review of 16 cases. Pediatr Radiol. Feb 2 2008
  • Paraseptal emphysema mimicking unilateral lymphangitic carcinomatosis: CT findings. J Comput Assist Tomogr. Sep-Oct 1993;17(5):810-2
  • Lobar extent of pulmonary lymphangitic carcinomatosis. Tl-201 chloride and Tc-99m MIBI scintigraphic findings. Clin Nucl Med. Sep 1996;21(9):726-9
  • Pulmonary lymphangitic carcinomatosis (PLC): spectrum of FDG-PET findings. Clin Nucl Med. Nov 2006;31(11):673-8
  • Clinical significance of small pulmonary nodules with little or no 18F-FDG uptake on PET/CT images of patients with nonthoracic malignancies. J Nucl Med. Jan 2007;48(1):15-21
  • Pulmonary lymphangitic carcinomatosis (PLC): spectrum of FDG-PET findings. Clin Nucl Med. Nov 2006;31(11):673-8
  • Fluorodeoxyglucose positron emission tomography pattern of pulmonary lymphangitic carcinomatosis. J Comput Assist Tomogr. May-Jun 2005;29(3):346-9
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