A chest CT scan may be helpful in the diagnosis of hilar adenopathy. Findings on CT scan diagnostic of tuberculosis, sarcoidosis, lymphoma, and other malignancies. Abdominal and pelvic CT scan in combination with chest CT scan can be revealed in cases of supraclavicular adenopathy and the diagnosis of secondary neoplasm.

• CT scan may be helpful in the diagnosis of lymphadenopathy. Findings on CT scan suggestive of lymphadenopathy include:^[1][2][3][4]

• Most nodes: 10 mm in short-axis
• Sub-mental and sub-mandibular: 15 mm
• Retropharyngeal: 8 mm
• Loss of fatty hilum
• Focal necrosis
• Cystic necrotic nodes
• Long-to-short axis ratio (>2cm – usually benign)

• The upper limit in the size of a normal node varies with location.

• A chest CT scan may be helpful in the diagnosis of hilar adenopathy. Findings on CT scan diagnostic of tuberculosis, sarcoidosis, lymphoma, and other malignancies. Abdominal and pelvic CT scan in combination with chest CT scan can be revealed in cases of supraclavicular adenopathy and the diagnosis of secondary neoplasm.

PET/CT scan

• On PET/CT scan, lymphadenopathy can be further assessed via quantitation of FDG uptake, which is a surrogate of metabolic activity. Infectious, inflammatory, and neoplastic processes will show high FDG avidity. PET/CT is particularly useful for assessing the response of lymph nodes to systemic chemotherapy.