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What is it?
The beaded septum sign is a radiologic finding characterized by nodules arranged along the thickened interlobular septa, creating a “beaded” appearance. It is indicative of diseases that involve the lymphatics, such as sarcoidosis or lymphangitic carcinomatosis.
Characterized by
Nodules distributed along interlobular septa, producing a string-like or beaded pattern. The nodules may vary in size and occasionally demonstrate calcification.
Anatomically affecting
Interlobular septa within the secondary pulmonary lobule, which contain lymphatics, pulmonary veins, and connective tissue.
Causes include
- Most Common Causes:
- Granulomatous diseases: Sarcoidosis
- Lymphatic spread of malignancy: Lymphangitic carcinomatosis
- Other Causes include:
- Infection: Tuberculosis, fungal infections
- Inflammation: Chronic hypersensitivity pneumonitis
- Neoplasm: Metastatic cancer spreading along lymphatics Lymphoma
- Mechanical: Lymphatic obstruction
- Metabolic: Silicosis,
- Circulatory:Chronic pulmonary venous congestion.
- Smooth septal thickening may transition into irregular nodularity in chronic cases.
- Immune: Autoimmune interstitial lung disease
- Infiltrative:
Pulmonary lymphoproliferative disorders
Amyloidosis - Inherited
Pathophysiology
The beaded septum sign reflects the accumulation of inflammatory, infectious, or neoplastic material along lymphatic pathways within the interlobular septa. This results in:
- Thickening of interlobular septa
- Nodular deposition along lymphatics, creating a beaded appearance
Histopathology
- Granulomatous inflammation (e.g., sarcoidosis)
- Lymphatic tumor spread (e.g., carcinoma)
- Fibrosis and mineral deposition (e.g., silicosis)
Imaging
Applied Anatomy
- Parts: Nodules arranged along interlobular septa
- Size: Small, discrete nodules (typically ≤1 cm)
- Shape: Round or oval nodules along linear septal thickening
- Position: Peripherally located in the lungs, outlining interlobular septa
- Character: Nodules may be calcified (e.g., granulomatous processes)
- Time: Chronic or progressive depending on the underlying cause
CXR
- May show a reticular or reticulonodular pattern.
- Less sensitive for detecting the beaded nodules compared to CT.
- Subtle linear opacities corresponding to thickened septa may be visible, particularly in advanced disease.
CT
- Key Modality:
- Beaded or nodular appearance of interlobular septa, outlining the secondary pulmonary lobules.
- Nodules are smooth, round, or calcified depending on the underlying etiology.
- Septal thickening is more prominent in peripheral lung regions and can involve both upper and lower lobes depending on the disease.
- Calcifications are more likely in chronic granulomatous diseases (e.g., sarcoidosis, silicosis).
- Distribution may show upper lobe predominance (sarcoidosis, silicosis) or diffuse patterns (lymphangitic spread).
- Chest CT provides a detailed assessment of septal involvement and associated parenchymal changes (e.g., ground-glass opacities, nodules, or fibrotic changes).
- Multiplanar reconstructions (MPR) can help differentiate between nodular septal thickening and small airway or vascular abnormalities.
- Contrast-enhanced CT can help assess vascular and lymphatic involvement in neoplastic or inflammatory conditions.
MRI
- Rarely used but may demonstrate high signal intensity in lymphatic infiltration on T2-weighted images.
PET-CT
- Increased metabolic activity may be present in:
- Malignant lymphatic spread (e.g., lymphangitic carcinomatosis)
- Active granulomatous diseases (e.g., sarcoidosis)
Other
- Not applicable.
Differential Diagnosis
- Sarcoidosis: Most common association; typically involves the upper lobes
- Lymphangitic carcinomatosis: Associated with malignancy, irregular nodular septal thickening
- Silicosis: Nodular septal thickening with calcification
- Tuberculosis or fungal infections: Infectious nodular septal involvement
- Pulmonary edema: Smooth septal thickening may mimic this finding but lacks nodularity
Recommendations
- Further Imaging:
- Chest CT to evaluate nodular pattern and associated findings
- Laboratory Correlation:
- Serum ACE levels for sarcoidosis
- Microbiological testing for infectious causes (e.g., fungal cultures, sputum AFB)
- Tumor markers in suspected malignancy
- Biopsy: Considered in cases of unclear etiology or to confirm malignancy or granulomatous disease.
Key Points and Pearls
- The beaded septum sign represents nodular thickening of interlobular septa, a key finding in lymphatic processes.
- Most commonly seen in sarcoidosis and lymphangitic carcinomatosis.
- Calcified nodules along septa suggest chronic granulomatous processes.
- Requires clinical, imaging, and laboratory correlation for diagnosis.
- Most Common Causes:
3 months later the patient presented with chest pain and a cough. CT of the chest in the axial plane shows new bilateral lower lobar regions of irregular interlobular septal thickening noted in the right lower lobe a, magnified in b). Ringed in image c and d are 2 side by side secondary lobules with irregular septal thickening centrilobular nodules and other intralobular nodules likely reflecting lymphatic involvement.
Given the changes in the right upper lobe these findings likely reflect lymphangitis carcinomatosa
Ashley Davidoff MD TheCommonVein.net 013Lu 136062cL
72 year old female showing reticular changes at the lung bases characterised by irregular thickening of the interlobular septa geometric distortion of the secondary lobules changes Ashley Davidoff TheCommonVein.net
136228
Reticulation ILD Geometric Distortion of the Secondary Lobules
72 year old female showing reticular changes at the lung bases characterised by irregular thickening of the interlobular septa geometric distortion of the secondary lobules changes Ashley Davidoff TheCommonVein.net
136229
70-year-old female presents with a cough, fever and leukocytosis. CT in the axial plane shows extensive lymphangitis characterized by thickening of the interlobular septa in the inferior aspect of the upper lobe below the necrotizing pneumonia.
Ashley Davidoff MD TheCommonVein.net 260Lu 31631c
3 months later the patient presented with chest pain and a cough. CT of the chest in the axial plane shows new bilateral lower lobar regions of irregular interlobular septal thickening noted in the right lower lobe a, magnified in b). Ringed in image c and d are 2 side by side secondary lobules with irregular septal thickening centrilobular nodules and other intralobular nodules likely reflecting lymphatic involvement.
Given the changes in the right upper lobe these findings likely reflect lymphangitis carcinomatosa
Ashley Davidoff MD TheCommonVein.net 013Lu 136062cL
3 months later the patient presented with chest pain and a cough. CT of the chest in the axial plane shows new bilateral lower lobar regions of irregular interlobular septal thickening bilaterally more prominent on the right with nodular changes at the left base.
Given the changes in the right upper lobe these findings likely reflect lymphangitis carcinomatosa
Ashley Davidoff MD TheCommonVein.net 013Lu 136063
50 year old female with primary adenocarcinoma with the primary lesion presenting as pneumonic consolidation of the left lower lobe, and diffuse reticulonodular changes bilaterally
Image b is a magnified view of the left upper lobe and shows nodular thickening of the interlobular septa representing lymphatic spread along the lymphovascular bundles (pink oval)
The right lung shows interlobular septal thickening centrilobular nodules, and nodular thickening of the minor fissure
These findings are consistent with the diagnosis of lymphangitis carcinomatosa
Ashley Davidoff MD TheCommonVein.net 158Lu 131023c01L
50-year-old female with diabetes, chronic renal failure and congestive heart failure. CT in the axial plane through the right posterior recess, shows thickened interlobular septa at the right base, congested arterioles (light blue arrowheads, b), alongside the bronchioles, peribronchial cuffing (white arrowheads, b), a congested pulmonary venule in the interlobular septum (red arrowhead arrowheads, b), ground glass changes and a secondary lobule demonstrating mosaic attenuation (black arrowhead arrowheads, b). The IVC is dilated and a small complex effusion is present.
Ashley Davidoff MD TheCommonvein.net 135783cL 193Lu
74-year-old man presents with dyspnea and orthopnea. CT shows thickening of the interlobular septa (Kerley B lines), peribronchial cuffing, and enlargement of the lobular arteriole in the right lower lobe. There is a suggestion of vasoconstriction of the arteriole as it enters the secondary lobule. ground glass changes in the some of the secondary lobules on the left and perhaps mosaic attenuation vs normal secondary lobule at the right base are noted. Additionally, there are small bilateral effusions right greater than left. The mild irregular shape of the effusions suggests that they are partially loculated. These findings indicate moderate congestive heart failure with interstitial edema.
Ashley Davidoff MD TheCommonVein.net 135775c01
Culture
Beads have played a significant role in various cultures worldwide, serving as symbols of status, spirituality, and artistic expression. Here are some notable examples:
Maasai Beadwork
The Maasai people of Kenya and Tanzania are renowned for their intricate beadwork, which conveys social status, age, marital status, and other cultural identifiers. Each color and pattern holds specific meanings, making each piece a unique cultural identifier.
Zulu Beadwork
In Zulu culture, beadwork is a form of expression, particularly among women. Beaded ornaments are created for family members and convey aspects of the wearer’s identity and social status.
Native American Beadwork
Various Native American tribes, such as the Lakota and Kiowa, have rich traditions of beadwork. Beads are used to create intricate designs on clothing and accessories, often holding cultural and spiritual significance.
Venetian Glass Beads
Venice has a long history of glass bead production, with beads being integral to trade networks between Europe, Africa, and the Americas. These beads influenced local bead-making traditions and were integrated into indigenous cultures.
Beads have played a significant role in various cultures worldwide, serving as symbols of status, spirituality, and artistic expression. Here are some notable examples:
Maasai Beadwork
The Maasai people of Kenya and Tanzania are renowned for their intricate beadwork, which conveys social status, age, marital status, and other cultural identifiers. Each color and pattern holds specific meanings, making each piece a unique cultural identifier.
Zulu Beadwork
In Zulu culture, beadwork is a form of expression, particularly among women. Beaded ornaments are created for family members and convey aspects of the wearer’s identity and social status.
Native American Beadwork
Various Native American tribes, such as the Lakota and Kiowa, have rich traditions of beadwork. Beads are used to create intricate designs on clothing and accessories, often holding cultural and spiritual significance.
Venetian Glass Beads
Venice has a long history of glass bead production, with beads being integral to trade networks between Europe, Africa, and the Americas. These beads influenced local bead-making traditions and were integrated into indigenous cultures.
Chumash Shell Beads
The Chumash people of California used shell beads as a form of currency and in social systems to build networks and accumulate wealth, minimizing the risk of food shortages.
These examples highlight the diverse cultural significance of beads across different
Architecture
Pinnacles, studded with crockets, on King’s College Chapel, Cambridge.
Literature
Shakespeare
The only Shakespeare quote that directly mentions “beads” is from “Richard II” where the line reads, “I’ll give my jewels for a set of beads, My gorgeous palace for a hermitage…”. This line essentially expresses the idea of willingly giving up luxurious possessions for something simple and spiritual.
Ralph Waldo Emerson
Dream delivers us to dream, and there is no end to illusion. Life is like a train of moods like a string of beads, and, as we pass through them, they prove to be many-colored lenses which paint the world their own hue. . . .
Links and References
Fleischner Society
beaded septum sign
CT scans.—This sign consists of irregular and nodular thickening of interlobular septa reminiscent of a row of beads (,Fig 10). It is frequently seen in lymphangitic spread of cancer and less often in sarcoidosis (,24).