This post is in response to the post “Pains in the neck.”
To summarize, this was a 4-year-old boy who was brought into the ED for right neck swelling that is erythematous and painful. An ultrasound was performed and the following images were obtained:
Thank you to everyone who took the quiz!
For question #1, 57% of you guessed correctly that this was an image of lymphadenitis, rather than parotitis (17%), Lemierre’s disease (17%) or a peritonsillar abscess (10%).
For question #2, 30% of you guessed correctly that increased peripheral vascularity is associated with lymphadenitis, rather than heterogeneous echogenicity (33%) or anechoic collections (27%) which are associated with abscesses. A normal lymph node typically measures around 1 cm (10%).
(Correction: In the original quiz posted on March 22, 2016, one of the answers for question #2 was “increased peripheral vascularity.” The answer should have read “increased hilar vascularity” and has since been corrected in the original post.)
A normal lymph node is usually visualized as a long or oval-shaped hypoechoic, homogeneous mass that typically measures less than 1cm in diameter. It will have an echogenic hilus, which will appear as an hyperechoic linear structure that is continuous with the adjacent fat. Hilar vascularity can be seen in normal as well as reactive lymph nodes.
While not discussed further here, sonographic findings such as peripheral vascularity, round shape, avascular areas, or heterogeneous echogenic foci (calcifications, nodules, necrosis) may be concerning for malignancy and should prompt further evaluation.
Lymphadenitis appears as a sharply demarcated, oval, hypoechoic mass with a central hilum, as seen in our patient. If color Doppler were applied, hilar vascularity would be present. Due to the inflammation, it may be larger in comparison to the noninfected, contralateral lymph node. Anechoic fluid collections or increased heterogeneity may suggest a more complicated lymph node pathology, such as abscess, necrosis or malignancy.
Sonographically, a normal parotid gland is a hyperechoic structure that is more homogeneous than adjacent structures due its fatty glandular tissue. In parotitis, the gland is enlarged and has a markedly heterogeneous pattern, with multiple small hypoechoic round areas measuring 2-4 mm in diameter which represent sialectases of the peripheral ducts of the parotid gland. Parotitis is usually unilateral, whereas mumps is generally bilateral. Below, is an image of parotitis (left) compared to the normal contralateral parotid gland (right).
A peritonsillar abscess most commonly appears as an enlarged heterogeneous mass in the tonsillar area. Comparison to the contralateral side may be helpful in differentiating between peritonsillar abscess from cellulitis. The transcutaneous approach can be performed with a linear transducer and is more comfortable for the patient.
However, the added advantage of the intraoral approach, which can be performed with either an endocavitary or hockey stick probe, is that surrounding vascular structures can be visualized during guided aspiration.
Lemierre’s disease is the penetration of a primary oropharyngeal infection into the lateral pharyngeal space which develops into a suppurative thrombophlebitis of the internal jugular vein with metastatic infections resulting from septic emboli. Sonographic findings of Lemierre’s demonstrate a thrombus of the internal jugular vein.
If you want to see YOUR image included in the next Image of the Month, please email interesting stills and/or clips in addition to a small blurb on the patient to Lorraine Ng at PEMFellowscom@gmail.com.
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- Answer: “Pains in the neck” - March 25, 2016