Answer for BIR CoW 26 Nov 2023
MASTICATOR SPACE SCHWANNOMA
Findings
A relatively well defined T2 heterointense lesion showing restricted diffusion is seen centered in the left masticator space. Superiorly involving the left temporalis muscle and exerts mass effect over lateral wall of left orbit causing its anterior bowing. Left foramen ovale appears widened. No evidence of intracranial extension. Inferiorly extending to the left angle of mandible and infiltrating the left masseter, left ramus of mandible. The lesion is displacing the parapharyngeal fat medially, posterolaterally displacing the left parotid gland. Anteriorly causing mass effect and compression of left maxillary sinus On contrast administration, strong heterogenous peripheral enhancement with central non – enhancing areas.
Discussion
Tumors of the masticator space: Nerve sheath tumors are the most frequent benign tumors of the masticator space. schwannoma is the most common tumor, followed by neurofibroma. These tumors are related to the mandibular division of the trigeminal nerve. Schwannoma appears as a well circumscribed fusiform mass within the masticator space with extension along the V3 nerve through the foramen ovale. On CT, schwannoma is most commonly higher in attenuation than adjacent muscle and show avid contrast enhancement. Widening of foramen ovale can be demonstrated. MR imaging - intermediate signal on T1-weighted images and hyperintensity on T2-weighted images with marked contrast enhancement.
OTHER BENIGN MASTICATOR SPACE TUMORS:
Neurofibroma
Hemangioma
Fibrosing inflammatory pseudotumour
Desmoid type fibromatosis
Findings
A relatively well defined T2 heterointense lesion showing restricted diffusion is seen centered in the left masticator space. Superiorly involving the left temporalis muscle and exerts mass effect over lateral wall of left orbit causing its anterior bowing. Left foramen ovale appears widened. No evidence of intracranial extension. Inferiorly extending to the left angle of mandible and infiltrating the left masseter, left ramus of mandible. The lesion is displacing the parapharyngeal fat medially, posterolaterally displacing the left parotid gland. Anteriorly causing mass effect and compression of left maxillary sinus On contrast administration, strong heterogenous peripheral enhancement with central non – enhancing areas.
Discussion
Tumors of the masticator space: Nerve sheath tumors are the most frequent benign tumors of the masticator space. schwannoma is the most common tumor, followed by neurofibroma. These tumors are related to the mandibular division of the trigeminal nerve. Schwannoma appears as a well circumscribed fusiform mass within the masticator space with extension along the V3 nerve through the foramen ovale. On CT, schwannoma is most commonly higher in attenuation than adjacent muscle and show avid contrast enhancement. Widening of foramen ovale can be demonstrated. MR imaging - intermediate signal on T1-weighted images and hyperintensity on T2-weighted images with marked contrast enhancement.
OTHER BENIGN MASTICATOR SPACE TUMORS:
Neurofibroma
Hemangioma
Fibrosing inflammatory pseudotumour
Desmoid type fibromatosis
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!