Answer for BIR CoW 15 Aug 2021
ETHMOID MUCOCELE
Findings
Evidence of T1 hypointense ,T2 / FLAIR hyperintense lobulated cystic lesion noted arising from left ethmoid air cells causing bony expansion of left lamina papyracea and extension of the lesion into the extraconal space of left orbit causing displacement of left medial rectus and left optic nerve laterally and extend of lesion into left side of frontal sinus.
Discussion
Paranasal sinus mucoceles are epithelium-lined cystic masses, are mucus filled, and result from obstruction of sinus ostia. Mucus accumulation causes enlargement of the mass with associated sinus bony wall expansion that is considered to be sine qua non for this entity. Prostaglandins and collagenases aid in osteolysis and further enhance the expansile nature of the cysts The frontal sinus is most commonly affected followed by the ethmoid sinuses The general mechanisms of cyst formation are inflammation, trauma, or tumor distortion of sinus outflow tracts. In addition to inflammatory obstruction of ostia, primary causes also include cystic dilation of mucosal glands or polyp degeneration. Secondary causes most commonly result from previous sinus surgery or facial trauma. Symptoms vary depending on the location of the mucocele and may be classified as rhinological, neurologic, or most frequently ophthalmologic In general, fronto-ethmoidal involvement causes mass effect upon the orbit leading to proptosis, hypophthalmos, diplopia, and periorbital swelling. Conversely, visual compromise is more common with posterior ethmoid and sphenoid mucoceles because the thin walled lamina papyracea may be displaced into the optic canal by an expanding mucocele CT scan findings show an expansile, homogenous sinus mass that is not rim-enhancing, unless associated with an acute mucopylocele. Bony destruction is not common but expansion and remodeling of bone is seen in association with the mucocele . MRI is superior in identifying the relationship of the mucocele to neighboring soft tissue and in distinguishing from other soft tissue neoplasms. Signal intensity of T1WI and T2WI is dependent upon the viscosity and fluid content of the cyst . On T2WI, mucoceles are hyperintense owing to their high water content. With time, the intensity may diminish due to chronic inspissations. In contrast, T1WIs have low signal intensity initially but, with water absorption and increased protein concentration over time, a more viscous mucocele changes from an isointense to hyperintense structure Surgical excision is the treatment of choice and early intervention is indicated to prevent visual compromise
Findings
Evidence of T1 hypointense ,T2 / FLAIR hyperintense lobulated cystic lesion noted arising from left ethmoid air cells causing bony expansion of left lamina papyracea and extension of the lesion into the extraconal space of left orbit causing displacement of left medial rectus and left optic nerve laterally and extend of lesion into left side of frontal sinus.
Discussion
Paranasal sinus mucoceles are epithelium-lined cystic masses, are mucus filled, and result from obstruction of sinus ostia. Mucus accumulation causes enlargement of the mass with associated sinus bony wall expansion that is considered to be sine qua non for this entity. Prostaglandins and collagenases aid in osteolysis and further enhance the expansile nature of the cysts The frontal sinus is most commonly affected followed by the ethmoid sinuses The general mechanisms of cyst formation are inflammation, trauma, or tumor distortion of sinus outflow tracts. In addition to inflammatory obstruction of ostia, primary causes also include cystic dilation of mucosal glands or polyp degeneration. Secondary causes most commonly result from previous sinus surgery or facial trauma. Symptoms vary depending on the location of the mucocele and may be classified as rhinological, neurologic, or most frequently ophthalmologic In general, fronto-ethmoidal involvement causes mass effect upon the orbit leading to proptosis, hypophthalmos, diplopia, and periorbital swelling. Conversely, visual compromise is more common with posterior ethmoid and sphenoid mucoceles because the thin walled lamina papyracea may be displaced into the optic canal by an expanding mucocele CT scan findings show an expansile, homogenous sinus mass that is not rim-enhancing, unless associated with an acute mucopylocele. Bony destruction is not common but expansion and remodeling of bone is seen in association with the mucocele . MRI is superior in identifying the relationship of the mucocele to neighboring soft tissue and in distinguishing from other soft tissue neoplasms. Signal intensity of T1WI and T2WI is dependent upon the viscosity and fluid content of the cyst . On T2WI, mucoceles are hyperintense owing to their high water content. With time, the intensity may diminish due to chronic inspissations. In contrast, T1WIs have low signal intensity initially but, with water absorption and increased protein concentration over time, a more viscous mucocele changes from an isointense to hyperintense structure Surgical excision is the treatment of choice and early intervention is indicated to prevent visual compromise
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!