Differential Diagnosis for a Dense and Firm Rubbery Movable Lymph Node
Single Most Likely Diagnosis
- Reactive Lymphadenitis: This condition is a likely diagnosis given the initial presentation with pain associated with a gum abscess, followed by the development of a dense, firm, and painless lymph node. The body's immune response to the infection could have caused the lymph node to become reactive, leading to its enlargement and firmness.
Other Likely Diagnoses
- Tuberculous Lymphadenitis: Although less common, tuberculosis (TB) can cause lymphadenopathy that presents as a firm, movable lymph node. The initial pain could have been due to the acute infection, and the subsequent painlessness could indicate a chronic process.
- Cat Scratch Disease: Caused by Bartonella henselae, this condition can lead to lymphadenopathy that is often painful at first but may become painless over time. The history of a gum abscess might not be directly related, but the disease can cause lymph nodes to become firm and rubbery.
- Sarcoidosis: This systemic disease can cause lymphadenopathy among other symptoms. While it might not directly relate to the gum abscess, sarcoidosis can lead to firm, movable lymph nodes.
Do Not Miss Diagnoses
- Lymphoma: Although less likely, lymphoma (both Hodgkin and non-Hodgkin) can present with firm, rubbery lymph nodes. The initial pain and subsequent painlessness do not rule out lymphoma, making it a critical diagnosis not to miss due to its significant implications for treatment and prognosis.
- Metastatic Cancer: Certain cancers, particularly those of the head and neck, can metastasize to lymph nodes, causing them to become firm and enlarged. Given the history of a gum abscess, which could potentially be a sign of an underlying malignancy, metastatic cancer must be considered.
Rare Diagnoses
- Kikuchi-Fujimoto Disease: A rare form of lymphadenitis that can present with firm, movable lymph nodes, often accompanied by systemic symptoms. It's more common in young women and can be self-limiting.
- Kimura Disease: Characterized by the presence of firm, subcutaneous nodules in the head or neck region, often accompanied by lymphadenopathy and eosinophilia. It's rare and more commonly found in Asian males.
- Castleman Disease: A rare disorder that can cause lymphadenopathy, among other symptoms. It can present in a localized form, which might fit the description of a firm, movable lymph node.