0:01

When we consider multiple parotid masses,

0:03

there is a relatively limited differential diagnosis.

0:07

90% of these are going to be either

0:09

Warthin's tumors or lymph nodes.

0:12

Warthin's tumors,

0:13

as I mentioned previously, have a 30% rate of

0:16

multiplicity, and that includes both bilateral

0:19

lesions, as well as unilateral multiple lesions,

0:22

as well as parotid masses with

0:25

extraparotid Warthin's tumors.

0:27

Lymph nodes are pretty common to be found in the

0:31

parotid gland as very small subcentimeter lesions

0:34

that are well defined and often

0:36

are kidney bean-shaped.

0:38

The other considerations for parotid masses

0:42

include cysts, acinic cell carcinoma, which is an

0:45

unusual malignancy of the parotid gland

0:48

but has a 3% bilateral rate.

0:52

Oncocytomas, metastases,

0:54

obviously, since the parotid gland

0:56

has lymphatics within it,

0:58

it can have lymph node metastases within it and

1:01

those are usually from adjacent skin cancer.

1:04

So a melanoma of the skin or a squamous cell

1:07

carcinoma of the skin adjacent to the ear or

1:11

along the angle of the mandible might lead to

1:14

intraparotid malignant metastatic lymph nodes.

1:17

And then benign lymphoepithelial lesions

1:19

or lymphoepithelial cysts.

1:21

These are the lesions that are associated with

1:23

Sjogren's syndrome and AIDS that account for the

1:26

enlargement and discomfort that these patients

1:29

have within their parotid glands.

1:33

If you are confused and don't know what the

1:36

potential diagnosis is with multiple

1:39

lesions in the parotid glands,

1:40

particularly if they're solid,

1:42

one way of doing the differential diagnosis

1:45

or assessing it is through the technetium

1:47

pertechnetate scan.

1:50

This situation, although the normal parotid tissue

1:52

takes up some contrast, the lesion here

1:56

represented a Warthin's tumor with uptake of

1:59

technetium pertechnetate. The other lesions that

2:02

can simulate Warthin's tumor on technetium

2:05

pertechnetate nuclear medicine studies are

2:08

oncocytomas, which are very rare,

2:10

and rarely a malignancy.