Head and Neck Masses Part 2
Question and answer review of head and neck masses for radiology board review.
Show Notes/Study Guide:
What is the most common salivary gland tumor?
Pleomorphic adenoma (benign mixed tumor). This is most common in the parotid gland (90% in superficial lobe of the parotid) but can also occur in the submandibular and/or sublingual glands. Pleomorphic adenomas tend to be very T2 bright.
What is the second-most common salivary gland tumor?
A Warthin’s tumor. This is typically only seen in the parotid gland unlike a pleomorphic adenoma. These are most common in males. Bilateral in about 15% of cases.
If you see a parotid gland tumor that shows uptake with Tc99m-pertechnatate is this most likely a Warthin’s tumor or a pleomorphic adenoma?
Warthin’s tumor. “War Tech” helps me remember this.
What is the most common malignant tumor of the minor salivary glands?
Mucoepidermoid carcinoma. Has an association with prior radiation to the head and neck.
Are malignant tumors more common in the smaller or larger salivary glands?
Malignant tumors are more common in the smaller salivary glands. The smaller the salivary gland, the more likely that a tumor involving the gland may be malignant.
For board exams, what is the most important finding associated with adenoid cystic carcinoma of the head and neck?
Perineural spread. When you think adenoid cystic carcinoma, you should next think of perineural spread in terms of board exam questions.
If you are shown images of the head and neck demonstrating a honeycombed appearance of both parotid glands with bilateral parotid masses that are found to be lymphoma, what is the most likely underlying disease state?
Sjogren’s syndrome which has a markedly increased risk of lymphoma of the parotid glands. Note that parotid lymphoma may be primary (parotid has internal lymph nodes) or secondary. Differential for diffuse abnormal appearance of parotid gland with mixed solid and cystic lesions is HIV benign lymphoepithelial disease of the parotid.
Correction: Note that the episode and originally posted study guide contains an error here. Wharton’s duct was incorrectly stated to be associated with the sublingual gland. Wharton’s duct is associated with the SUBMANDIBULAR gland.
Bonus: Which salivary gland is the Stensen’s duct and the Wharton’s duct each associated with?
Stensen’s duct: parotid gland. Wharton’s duct: submandibular gland.
If you are presented with enlarged lymph nodes in the carotid space what is the #1 differential consideration?
Squamous cell carcinoma nodal metastases.
A head and neck mass that demonstrates the classic salt and pepper appearance on MRI should make you think of which entity first?
Paraganglioma. The salt and pepper appearance results from a highly vascular mass that contains foci of hemorrhage. The dark areas (pepper) result from flow voids from the high vascularity and the bright areas (salt) result from internal hemorrhage.
Paragangliomas classically light up on which nuclear medicine exam?
In111 Octreotide due to presence of somatostatin receptors. By extension you would also expect uptake to be seen on Ga68 Dotatate PET/CT.
Can you name the principal tumors of the head and neck region that are paragangliomas?
In no order: carotid body tumor, glomus jugulare, glomus vagale, glomus tympanicum. Note that a pheochromocytoma is also considered a paraganglioma but is classic for adrenal glands instead of a head and neck primary mass. A glomus jugulotympanicum also technically exists when a glomus jugulare involves the middle ear cavity but that is perhaps extra credit knowledge.
What is a classic imaging feature of a carotid body tumor?
Carotid body tumors classically present as a mass at the carotid bifurcation that splay the internal carotid artery and external carotid artery.
What is a classic imaging feature of a glomus jugulare?
A glomus jugulare classically presents as a skull base mass with osseous destruction of the jugular foramen.
What is a classic imaging feature of a glomus vagale?
A glomus vagale classically presents as a mass between the carotid bifurcation and the jugular foramen. To be clearer these classically are located deep to the carotid arteries (internal and external) and in front of the internal jugular vein. Carotid body tumor will splay the ICA and ECA apart. A glomus vagale will push the ICA/ECA forward and the internal jugular vein back.
What is a classic imaging feature of a glomus tympanicum?
A mass with salt and pepper appearance confined to the middle ear, positioned over the cochlear promontory.
What is an imaging feature that can help differentiate between a schwannoma and a paraganglioma?
Compared to a paraganglioma, a schwannoma would be less vascular, therefore not show the classic salt and pepper appearance on MRI.
