Sarcoidosis: Although more common in adults, sarcoidosis can occur in children and is known for causing hilar lymphadenopathy. It's an autoimmune disease that can affect multiple organs, including the lungs.

Tuberculosis (TB): TB is a common cause of hilar lymphadenopathy, especially in regions where TB is prevalent. It's a bacterial infection that primarily affects the lungs but can spread to other parts of the body.
Lymphoma: Both Hodgkin and non-Hodgkin lymphoma can present with hilar lymphadenopathy. Lymphomas are cancers of the immune system and can occur in children.
Infectious Mononucleosis: Caused by the Epstein-Barr virus, infectious mononucleosis can lead to lymphadenopathy, including in the hilar region, although it's more commonly associated with cervical lymphadenopathy.

Lymphangitic Carcinomatosis: Although rare in children, this condition involves the spread of cancer to the lymphatic vessels in the lungs and can cause hilar lymphadenopathy. It's crucial to consider in the differential due to its severe prognosis.
Wegener's Granulomatosis (Granulomatosis with Polyangiitis): A rare autoimmune disorder that can cause inflammation in the blood vessels, including those in the lungs, leading to hilar lymphadenopathy.
Histoplasmosis: A fungal infection that can cause lymphadenopathy, including in the hilar region, especially in endemic areas.

Castleman Disease: A rare disorder that involves an overgrowth of cells in the lymphatic system, which can lead to lymphadenopathy, including in the hilar region.
Kikuchi-Fujimoto Disease: A rare, self-limiting condition that causes lymphadenopathy, more commonly in the cervical region but can potentially involve the hilar lymph nodes.
Kimura Disease: A rare, chronic inflammatory disorder that can cause lymphadenopathy and eosinophilia, more commonly seen in Asian males.