Easy to Learn - Radiological imaging of salivary gland diseases.

1. RADIOLOGICAL IMAGING OF
SALIVARY GLAND DISEASES.
Presented by: Syed Yousaf Farooq

5. Imaging modalities available to assess salivary glands
include:
Plain film radiography.
Sialograph
yCT scan.
MRI.
Diagnostic
ultrasound. Nuclear
scintigraphy.
These imaging modalities play an important role in evaluating a
patient with pain, swelling, or other symptoms related to possible
salivary gland disorders. Imaging helps in differentiating lesions of
salivary glands from those of parapharyngeal space, masticator
space, and mandible, submandibular and submental spaces. In
addition to localizing the lesion, it also aids in determining the extent
of disease, involvement of skull base, mandible, and neural spread in
case of malignant lesions.

6. Ultrasonography: High resolution Ultrasonography (7.5 – 10 MHz) of
parotid and submandibular salivary glands is actually a quick and
non invasive method for assessing these glands. It helps in the
assessment of vascularity of the gland, whether the lesion is solid or
cystic. It also helps in accurately guiding the FNAC needle to perform
biopsy from the suspected lesion.
It fails to demonstrate the parotid gland in its entirety because of
intervening mandible. It also does not clearly demonstrate the
intraglandular facialnerve branches.
Color Doppler studies of salivary glands indirectly identifies
malignant lesions of salivary glands as these lesions boast high
vascularity in comparison with their benign counterparts.
Radionuclide imaging: Is rarely used to evaluate salivary glands.
Sodium pertechnetate (technetium 99m) is the commonly used
element. This isotope is concentrated and excreted by salivary glands.
Since most salivary gland tumors do not accumulate the radionuclide,
a tumor mass will appear as a filling defecton
this scan. Tumors like warthin’s readily take up pertechnetate resulting
in formation of “Hot spots”.

13. DEVELOPMENTALANOMALIES.
Aberrant salivary glands.
An aberrant or ectopic is salivary gland tissue that
develop at a site where it is not normally found.
Aplasia and hypoplasia.
Aplasia occurs in combination with congenital
anomalies. Hypoplasia in patient with Melkersen
Rosenthal syndrome. Hyperplasia.
Accessory ducts. Most common developmental
anomalies. Atresia, congenital occlusion or
absence of one or two major salivary gland ducts.
Diverticulae, small pouches of ductal system of
one of the major salivary glands.
Congenital fistula.

16. Submandibular gland

18. Sialolithiasis, single (A) and multiple (B) in two different
patients, as detected on CT. Small inset on the right (C)
shows a multilayer structure that is observed in the majority
of calculi (hydroxyapatite)

19. Acute parotitis. US (longitudinal (A) and transverse (B)) shows an enlarged,
hypoechoic gland with multiple hypoechogenic areas corresponding to acinic
dilatations. Color Doppler register is increased (C).

20. Acute right-sided parotitis. Transverse, contrast-enhanced, fat-saturated, T1-
weighted SE MR image shows marked enhancement of the right parotid gland
(thick and thin arrows) compared with the left. The superficial subcutaneous
tissue is also inflamed.

21. Sialolithiasis and sialadenitis, as seen on color Doppler
ultrasound of the submandibular gland. Two small calculi, 2 and
3mm in size, respectively (arrows), are seen as hyperechoic
structures with posterior shadowing. The increased
vascularization of the slightly enlarged gland should be noted.

22. Recurrent sialadenitis of the parotid gland:
ultrasound and magnetic resonance
sialography findings.

23. Viral parotitis (mumps) on US. Image A) represents the two pairs
of glands on a longitudinal view, with pathological enlargement
of the right parotid, whereas image B) shows the asymmetry in a
transverse view.

25. Plunging or cervical Ranula

26. Left sublingual space extending to the
submandibular space consistent with a
plunging ranula (arrow).

27. Left parotid hemangioma

28. Bilateral parotid hemangiomas.

31. RADIOGRAPHIC FEATURES
CT: Smoothly marginated or Lobulated homogeneous small
spherical mass is the most common appearance. When
larger they can be heterogeneous with foci of necrosis.
Small regions of calcification are common .
When small enhancement tends to be prominent. In larger
tumours enhancement is less marked, but can demonstrate
delayed enhancement. MRI: They are commonly seen as well-
circumscribed and homogeneous when small. Larger tumours
may be heterogeneous.
Ultrasound:Typically hypoechoic. May show a lobulated
distinct border
+/- posterior acoustic enhancement.
Ultrasound is also useful in guiding biopsy (both FNAC and
core biopsies) but needs to be carried out with care to avoid
facial nerve damage .
Angiography (DSA): Typically hypovascular.

33. A Warthin tumour (or papillary cystadenoma lymphomatosum) is a
benign sharply demarcated tumour of the parotid gland. It is bilateral
in 10-15% of cases.
Epidemiology
They are the 2nd most common (up to 10% of all parotid tumours)
benign parotid tumour (after pleomorphic adenoma) and are the
commonest bilateral or multifocal benign parotid tumour. It typically
occurs in the elderly (6th decade). There is a recognised male
predilection. Patients typically present with painless parotid
swelling.
Morphology
They are often multi-centric (20%) and are usually small (1-4 cm).
They have a typically heterogenous appearance on all modalities,
often with cystic components (30%).
Location
Tends to favour the parotid tail region.
WARTHIN TUMOUR

34. RADIOGRAPHIC FEATURES
Has a greater tendency to undergo cystic change than any other
salivary gland tumour .
Ultrasound:
Usually seen as a relatively well defined, ovoid, hyperechoic mass. In
some cases
anechoic internal cystic areas may be present. They are often
hypervascular.
CT:
can be often seen bilaterally
classic appearance is a cystic lesion posteriorly within the parotid
with a focal tumour nodule
relatively well defined
cystic changes appear as intra lesion at lower attenuation, no
calcification MRI:
Well defined and can be bilateral.

35. Computed tomography of Warthin tumor. A: A large well-defined mass involves
the superficial lobe of the left parotid gland. The mass enhances diffusely. B: At
the level of the parotid tail, areas of lower density (arrowheads) are consistent
with cystic components observed in the posterior aspect of the mass.

36. Bilateral Warthin Tumors of the Parotid Gland on contrast-
enhanced CT

39. Magnetic resonance imaging of an oncocytoma in the right
parotid tail.

40. A MUCOEPIDERMOID CARCINOMA IS A TUMOR THAT USUALLY OCCURS IN THE
SALIVARY GLAND
Epidemioloy
Mucoepidermoid carcinomas are seen throughout all adult age groups, but are
most common in middle age (35-65 years of age) . However, it is the most
common malignant salivary gland tumour of childhood . Overall,
mucoepidermoid carcinomas account for :
2.8-15.5% of all salivary gland tumours
1-10% of all major salivary gland
tumours 6.5-41% of minor salivary
gland tumours
In the parotid gland they are the most common malignant primary
neoplasm. Clinical presentation
Mucoepidermoid carcinomas most frequently arise in the parotid gland, and
presents as a painless swelling, with or without facial nerve involvement.
These tumours can however be found anywhere there are salivary glands.
Overall distribution across various glands is as follows :
major salivary glands : 50%.
parotid gland : 40%.
submandibular gland :
7%. sublingual gland :
3%.
minor salivary glands : 50%.

41. RADIOGRAPHIC FEATURES:
Radiographic appearances largely depend on grade,
making preoperative imaging
important in planning and counseling.
Ultrasound:
Typically a well circumscribed hypoechoic, with an either
part of completely cystic appearance. The lesion stands
out against the relatively hyperechoic normal parotid gland.

42. MRI:
• Again, imaging is dependent on grade.
• Low grade tumors have similar appearances to
benign mixed tumors.
• T1 - low to intermediate signal ; low signal cystic
spaces
• T2 - intermediate to high signal ; cystic
areas will be high signal T1 C+ (Gd) -
heterogeneous enhancement of solid
components
• High grade tumors on the other hand have lower signal on T2 and
poorly defined margins and infrequent cystic areas.
• T1 - low to
intermediate
signal T2 -
intermediate to
low signal

43. Computed Tomography:
• Low grade tumors appear as well circumscribed masses, usually
with cystic components. The solid components enhance, and
calcification is sometimes seen. They have appearances similar to
benign mixed tumours.
• High grade tumours on the other hand, have poorly defined
margins, infiltrate locally and appear solid.

47. Computed tomography of a recurrent adenoid cystic carcinoma in a 49-year-old woman
who had previous right submandibular gland resection. An irregularly infiltrating
enhancing mass is seen in the floor of the mouth and parapharyngeal space. Anterior
fatty infiltration indicates hypoglossal nerve invasion

49. Adenocarcinoma of the right parotid gland.

51. Carcinosarcoma of the left parotid gland.

53. Axial and coronal contrast enhanced CT. The patient had previous surgery for
squamous cell carcinoma involving the parotid gland, these images demonstrate
recurrence within the parotid space. Note the involvement of the skin.

55. METASTASIS.
Most metastases to the parotid or submandibular
gland are from continuous spread of squamous
cell carcinoma of the pharynx or neck.
Hematogenous metastases have been described
in carcinoma
of the breast, neck, lung, and kidney and in
metastatic melanoma. Despite the vascularity of
the parotid gland, blood borne metastasis is rare.
Lymphatic metastases to the parotid glands also
are possible.

56. Metastasis to the parotid
glands

57. THANK YOU