Infection:
(1) fungal infection (Aspergillus, Mucor)
(2) abscess
(3) sinusitis
(4) Herpes simplex infection
(5) Mycobacterial infection (including leprosy)
Autoimmune disease:
(1) rheumatoid nodules
(2) Wegener's granulomatosis (granulomatosis with polyangiitis)
(3) IgG4-related sclerosing disorder
Vascular disorders:
(1) hemangiomas
(2) thrombosis of the cavernous sinus
(3) carotid-cavernous sinus fistula
(4) aneurysm
Tumors:
(1) schwannoma or other neural tumor
(2) metastatic carcinoma
(3) soft tissue tumor (rhabdomyosarcoma, etc)
(4) malignant lymphoma
(5) extramedullary hematopoiesis
Other:
(1) trauma
(2) inferior turbinate radiofrequency procedure
(3) foreign body
(4) sphenoethmoid mucocele
(5) sickle cell disease
