22
Salivary Glands and Rare Head and Neck Lesions
primary salivary gland tumor. Histologically, this tumor is more
cellular than ordinary cartilaginous tissue. Slight nuclear atypia
as well as binucleate cells may be observed.
Cytology
FNA smears are dominated by fibrillar chondroid fragments.
Nucleated cells are only rarely observed. They have indistinct
cellular borders, weakly stained nuclei, and pale blue cyto-
plasm (May-Grunwald-Giemsa). Cytologic distinction between
chondroma and pleomorphic adenoma with extensive chon-
droid metaplasia may be impossible.
Key features of chondroma
Chondroid fragments;
Few free-lying monomorphous cells; and
Cells with indistinct, pale blue cytoplasm.
Parathyroid Lesions
Cysts and tumors arising in the parathyroid glands may appear
as palpable lesions in the neck. Most commonly they are found
in close proximity to the thyroid gland but may appear as high
as in the submandibular region.
The cysts are thin-walled and contain a watery clear fluid,
which in most instances is free of cells. As much as 10 mL of
fluid can be aspirated from a large parathyroid cyst. Aspiration
of watery clear fluid from a neck cyst should raise a clinical sus-
picion of a parathyroid cyst. Parathormone analysis of the fluid
may reveal the nature of the cyst. Parathyroid cysts are rarely
associated with hyperparathyroidism.
Adenomas are solid tumors that in rare cases may be as large
as 7-8 cm in diameter. Patients do not always present with clini-
cal signs of hyperparathyroidism. Serum levels of calcium and
parathormone may be elevated. Sections show chief cells or
oxyphilic cells in trabeculae or cords in a vascular stroma.
Cytology
FNA smears contain many naked nuclei either dissociated or
in loosely attached groups (Fig. 22.33). Anisokaryosis is usu-
ally prominent. When present, the cytoplasm is large, oxyphilic,
Fig. 22.33 Parathyroid adenoma. Aspirate contains clusters of loosely
attached cells in follicular arrangement with indistinct granular cytoplasm
(May-Grunwald-Giemsa x HP).
or pale blue, sometimes vacuolated.73,74 The absence of colloid
is a helpful feature. The cytologic pattern of parathyroid ade-
noma in most instances allows a conclusive diagnosis. A fol-
licular tumor of the thyroid or a carotid body tumor may,
however, show a cytologic pattern similar to that of a parathy-
roid adenoma.73,74
Key features of parathyroid adenoma
Mostly dissociated cells;
Some loosely attached cell groups may occur;
Naked nuclei are common;
Anisokaryosis; and
Oxyphilic or pale blue, sometimes vacuolated
cytoplasm.
Nodular Fasciitis
This lesion commonly appears as a rapidly growing hard tumor
of the neck, trunk, or extremities in young patients, although
no sites or age groups seem to be spared. The tumor, usually
less than 5 cm in diameter, often has fascial attachment but can
be found in the subcutaneous tissue. Spontaneous regression
occurs within 2 to 3 months.75
Sections show monomorphous fibroblasts arranged in bun-
dles with collagen in a loose feathery pattern. Mitotic figures are
common. Large plump myofibroblasts as well as lymphocytes
and plasma cells are found.
Cytology
FNA smears
characteristically show ovoid fibroblasts
and
plump myofibroblasts dispersed in a granular eosinophilic
(May-Grunwald-Giemsa) background (Fig. 22.34). Collagen
fragments or myxoid substances can often be observed. The
fibroblasts have an ovoid nucleus and an elongated basophilic
cytoplasm with tapering ends. The larger myofibroblast has a
polygonal or triangular basophilic cytoplasm and an ovoid,
eccentrically positioned nucleus (see Fig. 22.34). Neutrophils,
eosinophils, lymphocytes, and plasma cells are present in
various proportions.
In most instances, the cytologic pattern is characteristic and
allows a conclusive diagnosis.75,76 The differential diagnosis
Fig. 22.34 Nodular fasciitis. Smear with fibroblasts and large plump cells
in a granular background. Collagen fragment and some lymphocytes are also
present (May-Grünwald-Giemsa x HP).
625
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