Answer for CoW 17 Sep 2017
Salivary gland tumour -pleomorphic adenoma
Findings
Lobulated well defined hyperintense lesion with internal scattered hypointense signals seen in the right parapharyngeal space measuring 5.1x5.2x3 cm, anteriorly abutting pterygoid muscles,posteriorly ipsilateral paravertebral muscles and carotid sheath.Superiorly the lesion abuts the skull base and laterally the right parotid gland.
Discussion
Tumours arising in the minor salivary gland accounts for 22% of all salivary gland neoplasms . Majority of them are malignant with only 18% being benign. Of the benign tumours pleomorphic adenoma is the commonest . The most common site of a pleomorphic adenoma of the minor salivary gland is the palate followed by lip, buccal mucosa, floor of mouth, tongue, tonsil, pharynx, retromolar area and nasal cavity.Pleomorphic adenoma arising de novo in the parapharyngeal space is of rare occurrence. Most common Parapharyngeal space tumors are PLEOMOROHIC ADENOMAS. Pleomorphic adenomas in the parapharyngeal space usually arise from deep lobe of the parotid, however they very rarely develop denovo from displaced or abberant salivary gland tissue within lymph node. CT scan is an important diagnostic tool in tumours of parapharyngeal space because it helps in determining the extent of disease, local spread and also help to some extent in determining the type of tumour. Contrast enhancement is seen in vascular and neurogenic tumours. Presence of intact fat plane helps in distinguishing benign tumours from malignant. Extension of tumours from the deep lobe of a parotid gland is distinguishable from tumour arising de novo in the parapharyngeal space by a fine lucent line representing the compressed layer of fibroadipose tissue between the tumour and deep lobe of parotid. Histopathologically, pleomorphic adenoma is an epithelial tumour of complex morphology, possessing epithelial and myoepithelial elements arranged in a variety of patterns and embedded in a mucopolysaccharide stroma. Formation of the capsule is as a result of fibrosis of surrounding salivary parenchyma, which is compressed by the tumour and is referred to as "false capsule" . FINAL DIAGNOSIS Pleomorphic adenoma of Minor Salivary Glands in Parapharyngeal Space
Findings
Lobulated well defined hyperintense lesion with internal scattered hypointense signals seen in the right parapharyngeal space measuring 5.1x5.2x3 cm, anteriorly abutting pterygoid muscles,posteriorly ipsilateral paravertebral muscles and carotid sheath.Superiorly the lesion abuts the skull base and laterally the right parotid gland.
Discussion
Tumours arising in the minor salivary gland accounts for 22% of all salivary gland neoplasms . Majority of them are malignant with only 18% being benign. Of the benign tumours pleomorphic adenoma is the commonest . The most common site of a pleomorphic adenoma of the minor salivary gland is the palate followed by lip, buccal mucosa, floor of mouth, tongue, tonsil, pharynx, retromolar area and nasal cavity.Pleomorphic adenoma arising de novo in the parapharyngeal space is of rare occurrence. Most common Parapharyngeal space tumors are PLEOMOROHIC ADENOMAS. Pleomorphic adenomas in the parapharyngeal space usually arise from deep lobe of the parotid, however they very rarely develop denovo from displaced or abberant salivary gland tissue within lymph node. CT scan is an important diagnostic tool in tumours of parapharyngeal space because it helps in determining the extent of disease, local spread and also help to some extent in determining the type of tumour. Contrast enhancement is seen in vascular and neurogenic tumours. Presence of intact fat plane helps in distinguishing benign tumours from malignant. Extension of tumours from the deep lobe of a parotid gland is distinguishable from tumour arising de novo in the parapharyngeal space by a fine lucent line representing the compressed layer of fibroadipose tissue between the tumour and deep lobe of parotid. Histopathologically, pleomorphic adenoma is an epithelial tumour of complex morphology, possessing epithelial and myoepithelial elements arranged in a variety of patterns and embedded in a mucopolysaccharide stroma. Formation of the capsule is as a result of fibrosis of surrounding salivary parenchyma, which is compressed by the tumour and is referred to as "false capsule" . FINAL DIAGNOSIS Pleomorphic adenoma of Minor Salivary Glands in Parapharyngeal Space
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!