Differential Diagnosis for Lymph Node in Groin Swelling

Single Most Likely Diagnosis

• Inguinal lymphadenitis: This is the most common cause of lymph node swelling in the groin, often resulting from a bacterial or viral infection in the lower limbs, such as cellulitis or an infected wound.

Other Likely Diagnoses

• Metastatic cancer: Cancers from the lower limb, genital area, or anal region can metastasize to the inguinal lymph nodes, causing swelling.
• Sexually transmitted infections (STIs): Certain STIs like syphilis, herpes simplex, or chlamydia can cause lymph node swelling in the groin.
• Fungal infections: Fungal infections such as sporotrichosis can cause lymphadenitis in the groin area.

Do Not Miss Diagnoses

• Lymphoma: Although less common, lymphoma can present with lymph node swelling in the groin and is critical to diagnose early due to its potential for serious morbidity and mortality.
• Tuberculosis: TB can cause lymphadenitis, including in the inguinal region, and is particularly important to consider in individuals from endemic areas or with compromised immune systems.
• HIV infection: Acute HIV infection can cause generalized lymphadenopathy, including swelling of the inguinal lymph nodes.

Rare Diagnoses

• Kikuchi disease: A rare form of lymphadenitis that can cause swelling of the lymph nodes, including those in the groin, often self-limiting but can mimic more serious conditions.
• Castleman disease: A rare disorder that involves an overgrowth of cells in the lymph nodes, which can cause lymph node swelling, including in the inguinal region.
• Filariasis: In areas where filariasis is endemic, it can cause lymphadenopathy, including in the groin, due to parasitic infection.