Hodgkin Lymphoma: This is often considered the most likely diagnosis due to its strong association with both mediastinal adenopathy and pruritus. Pruritus is a common symptom in Hodgkin lymphoma, occurring in up to 30% of patients.

Non-Hodgkin Lymphoma: While less commonly associated with pruritus than Hodgkin lymphoma, certain types of non-Hodgkin lymphoma can present with mediastinal adenopathy and systemic symptoms, including pruritus.
Sarcoidosis: This condition can cause mediastinal adenopathy and may be associated with skin symptoms, including pruritus, although it is less commonly linked to pruritus compared to lymphomas.
Lymphomatoid Papulosis: A rare skin condition that can be associated with lymphoma and may present with pruritus, although it is more commonly linked to skin lesions.

Lymphoma with Hypereosinophilic Syndrome: Although rare, this condition can present with severe pruritus and eosinophilia, and missing the diagnosis could lead to significant morbidity due to the potential for end-organ damage.
Mediastinal Germ Cell Tumor: While less common, these tumors can cause mediastinal adenopathy and, in rare cases, may be associated with pruritus or other systemic symptoms. Missing this diagnosis could lead to delayed treatment of a potentially curable malignancy.

Castleman Disease: A rare lymphoproliferative disorder that can cause mediastinal adenopathy and may be associated with systemic symptoms, including pruritus, although this is uncommon.
Kimura Disease: A rare, chronic inflammatory disorder that can cause lymphadenopathy and eosinophilia, and may occasionally present with pruritus, although it is more commonly associated with lymphadenopathy in the head and neck region.
Cutaneous T-Cell Lymphoma (e.g., Mycosis Fungoides): While primarily a skin condition, advanced stages can involve lymph nodes, including those in the mediastinum, and are often associated with severe pruritus. However, the primary presentation is usually cutaneous.