Giant nontraumatic intradiploic arachnoid cyst in a young male

Abstract

Intradiploic arachnoid cysts have scarcely been reported in the literature, most reported cases being secondary to trauma. Nontraumatic arachnoid cysts are quite rare and have been reported mostly in adults. Here, we report the case of a 16-year-old male presenting with a slowly growing mass in the occipital region and intermittent headaches. On the basis of the findings of X-rays, computed tomography scans, and magnetic resonance imaging scans of the head, the mass was diagnosed as a giant intradiploic arachnoid cyst.

Nontraumatic intradiploic arachnoid cyst of the sphenoid bone

“…The intraosseous bony cysts occur because of extension of arachnoid villi through the bony defects and are typically seen in post-traumatic cases and are likely associated with growing skull fractures [3] , [6] . This condition is also described in the literature as leptomeningeal cysts or post-traumatic arachnoid cyst or CSF fistula in cases of posttraumatic growing skull fractures [3] , [7] , [8] .…”

“…Occasionally, the intradiploic cysts may attain an enormous size and extend into the sphenoid sinus, orbits, infratemporal fossa, pterygomaxillary region, nasal cavity, and nasopharynx [1] , [2] , [6] . There are rare case reports in the literature that show different clinical manifestations and imaging findings of symptomatic intradiploic cysts.…”

“…Large intracranial arachnoid cysts rarely extend into the sphenoid sinus, causing clinical manifestations of proptosis, headache, and nasal symptoms and imaging appearance of the sphenoid mucocele [1] , [2] , [8] , [9] . The smaller nontraumatic asymptomatic intraosseous arachnoid cysts do not require surgical management unlike the large or growing lesions with significant clinical implications [5] , [6] , [10] .…”

“…Imaging did not reveal any features of involvement of the sphenoid sinus, orbits, pterygopalatine fossa, posterior nasal spaces, or posterior skull base. The possible differential diagnosis of lytic lesions of the greater wing of the sphenoid includes mucocele or overpneumatized lateral recesses of the sphenoid sinus, intradiploic arachnoid cyst, epidermoid cyst, plasmacytoma, aneurysmal bone cyst, cystic fibrous dysplasia, or metastasis [6] , [8] , [11] , [12] , [13] .…”

“…in 1989 [3] . These intraosseous cysts are mostly post-traumatic in origin and very rarely non-traumatic in nature and are mostly documented in occipital regions [4] , [5] , [6] . Intradiploic arachnoid cysts may pose diagnostic challenge, and understanding the clinicopathologic correlation and imaging characteristic is crucial to avoid any misinterpretations.…”