Differential Diagnosis for Hard Palpable Lymph Node

Single Most Likely Diagnosis

• Metastatic Cancer: This is often the first consideration for a hard, palpable lymph node, especially in adults, as it can be a sign of cancer spread from a primary site.

Other Likely Diagnoses

• Infectious Lymphadenitis: Bacterial, viral, or fungal infections can cause lymph nodes to become enlarged and hard.
• Reactive Lymphadenopathy: This is a response to infection or inflammation elsewhere in the body and can cause lymph nodes to become palpable and firm.
• Autoimmune Disorders: Conditions like rheumatoid arthritis or lupus can cause lymphadenopathy.

Do Not Miss Diagnoses

• Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can present with hard, painless lymphadenopathy, making it crucial not to miss this diagnosis due to its significant implications.
• Tuberculosis: Although less common in some regions, TB can cause hard lymph nodes, especially in the context of systemic symptoms like fever and weight loss.
• Cat-Scratch Disease: Caused by Bartonella henselae, this infection can lead to painful lymphadenopathy, but the nodes can become hard over time.

Rare Diagnoses

• Kikuchi-Fujimoto Disease: A rare, self-limiting condition that causes lymphadenopathy, often accompanied by fever and night sweats.
• Kimura Disease: A chronic inflammatory disorder that can cause hard, subcutaneous nodules and lymphadenopathy, more common in Asian males.
• Castleman Disease: A rare disorder that can cause lymphadenopathy, fever, and other systemic symptoms, often associated with HIV infection or other immunodeficiencies.

Each of these diagnoses has distinct implications for patient management and outcome, emphasizing the importance of a thorough diagnostic workup for a hard, palpable lymph node.