Normal lymph node US appearance
- < 1cm AP diameter
- Shape: oval (long axis), C-shaped (short-axis)
- Hypoechoic cortex
- Hyperechoic fatty hilum
- Uniform vascular hilum
Reactive lymph node
Normal response to local or systemic infection/ inflammation
Presents:
- Asymptomatic
- Swollen lump
Treatment:
- Treat underlying cause
Benign features:
- *Enlarged node**
- <1 cm AP diameter
- *Normal morphology**
- Oval, symmetrical cortex, fatty hilum, homogeneous, well defined,
Vascular hilum
Lymphadenitis
Inflammed lymph nodes
Causes
- Bacterial infection (strep throat, tonsilitis, ear infection, salivary gland infection)
- Viral infection (common cold, upper respiratory tract infection)
Presents:
- Swollen tender cervical mass
- Erythema
- Fever
- Raised inflammatory markers
Management:
- Antibiotics
- US to assess for abscess formation
- *Enlarged nodes**
- Normal morphology
Increased vascularity
- *Matted mass**
- Fused nodes
- *Abscess formation**
- *-** Heterogeneous mass
- Thick irregular walls
- Increased peripheral vascularity
Primary malignant lymph node (lymphoma)
Malignancy arising from lymphocytes
- Unknown cause
- Hodgkins (40%)
- Reed-Sternberg cells
- Metastasize → nearby nodes
- Better prognosis
- Non-Hodgkins (60%)
- No Reed-Sternberg cells
- Metastasize → random nodes
- B-cell: slower growing (more common)
- T-cell: aggressive
Present:
- Painless neck mass
- Fever
- Night sweats
- Weight loss
Treatment:
- Biopsy
- CT staging
- Surgical resection
- Chemo + radiation
Malignant features:
- *Multiple very hypoechoic nodes**
- *-** Absent hilum/ central necrosis
- Heterogeneous
- *Round**
- >1cm AP diameter
- Taller than wide
Lobulated/ irregular contour
Disorganised vascularity
Differential = mets (calcs)
Metastatic lymph nodes
Metastases implant in subcapsular or cortical sinusoids → cortical thickening
- Location of implant determines pattern of thickening
Diagnosis:
- Biopsy
Asymmetric cortical thickening
Very hypoechoic
Round
Microcalcifications
Central necrosis (severe)
Differential = benign reactive node (symmetric cortical thickening)
