Table 2.

Differential diagnosis table for Hodgkin’s Lymphoma.

	Location	CT	MRI	FDG-PET
Hodgkin Lymphoma	Lymph nodes, Axilla, Breast, Systemic.	Enlarged lymph node, often >1 cm. Circumscribed round or oval mass. Can have variable enhancement.	Ill-defined fatty mass. Heterogeneous enhancement on T1-weighted imaging. Can have rapid initial enhancement on kinetic analysis.	Mildly enhancing irregular soft tissue.
Sarcoidosis	Breast, Lungs, Systemic.	Pulmonary peri-lymphatic nodules.	Hilar and mediastinal lymphadenopathy.	Hypermetabolic bilateral mediastinal and hilar lymphadenopathy.
Invasive Ductal Carcinoma	Axillary tail, Breast.	Typically heterogeneous mass with irregular or spiculated margins.	Heterogeneous mass with irregular or spiculated margins. Variable internal enhancement. Rapid marked enhancement with early washout.	FDG-avid breast soft tissue lesion.
Infection (HIV, TB)	Depending on infectious agent: May be localized to focal area or systemic.	Typically enlarged lymph node, may have inflammatory peri-nodal stranding.	In systemic infection, would expect multiple enlarged lymph nodes. Size can be a nonspecific finding, however.	Marked enhancement from activated lymphocytes in round or oval circumscribed soft tissue.
Connective Tissue Disease (Rheumatoid Arthritis, Scleroderma, SLE)	Systemic, typically bilateral lymphadenopathy.	Features dependent on disease. Lymph node enlargement may be secondary to gold salt therapy for rheumatoid.	Features specific to disease, typically widespread systemic presentation.	Features are specific to disease.
Nonspecific Reactive Lymphadenopathy	May be unilateral or bilateral, diffuse, or focal.	Enlarged circumscribed lymph node. Preserved normal nodal morphology. Isodense to muscle on non-contrast and homogeneous contrast enhancement.	Well-defined enlarged lymph node. Preserved normal nodal morphology. T2-hyperintense and contrast enhancing.	Marked enhancement from activated lymphocytes in circumscribed soft tissue.