Page 249 - AIDSBK23C

Page 249

HEAD AND NECK PATHOLOGY IN AIDS

Though HIV can be found in both tears and saliva, the lacrimal glands and the salivary
glands do not show specific pathologic lesions in persons with HIV infection. The most
common clinical findings suggestive of salivary gland abnormalities include gland enlargement
and xerostomia. These findings are similar to those seen with Sjögren syndrome. Patients with
these lesions may not have reached the stage of clinical AIDS. Xerostomia has been reported in
2 to 10% of HIV-infected persons.[698]
Enlargement of major salivary glands is seen in 3 to 6% of HIV-infected adult patients
but up to 10% of HIV-infected children. Persistent generalized lymphadenopathy (PGL) that
affects lymphoid tissue in HIV infection can also affect intraparotid lymphoid tissue and lead to
parotid enlargement. The slow enlargement of the parotid gland may also consist of benign
lymphoepithelial lesions (BLEL). Such lesions may be bilateral, multiple, variably sized, and
may be accompanied by cervical lymphadenopathy. These lesions are thought to arise from
hyperplasia of intraparotid lymphoid tissue that traps small intraparotid ducts, causing
obstruction and dilation with cystic change and enlargement that can reach 5 cm in diameter.
These cystic lesions are termed benign lymphoepithelial cysts (BLEC).[1010]
Fine needle aspiration (FNA) cytology of a lymphoepithelial cyst yields usually yields
yellow fluid, but sometimes bloody or turbid fluid. Microscopic findings can mimic Sjögren
syndrome and include anucleate squames, lymphoid follicle center cells, and macrophages. The
surrounding salivary gland tissue typically demonstrates lymphoid infiltrates with cystic dilation
of gland ducts lined by pseudostratified squamous epithelium. The histologic features are similar
to those lesions seen in non-HIV-infected persons.[409, 1010,1011] Chronic, non-specific
sialadenitis occurs in a fourth of patients. The most common opportunistic infections diagnosed
in salivary glands include mycobacteria, cytomegalovirus, and cryptococci.[1012]
Other lymphoid lesions may occur. The entity known as diffuse infiltrative
lymphocytosis syndrome (DILS) typically involves the parotid glands bilaterally, leading to
facial swelling and sicca symptoms. The submandibular glands are involved in half of cases,
while the lacrimal glands are involved in a third of cases. This condition results from an
extensive parotid infiltration by CD8 lymphocytes, which can mimic Sjögren syndrome, or even
lymphoma. Other visceral organs may also be involved. In addition, lymphocytic interstitial
pneumonitis (LIP) is present in a third of cases, while myopathy may be seen in a fourth of
patients with DILS. This condition can present before the onset of clinical AIDS in HIV-
infected persons.[580]
Kaposi’s sarcoma (KS) can rarely involve submandibular and parotid salivary glands and
produce gland enlargement. The histologic appearance is similar to KS seen elsewhere, with
atypical spindle cells lining slit-like vascular channels, extravasated red blood cells, and hyaline
globules. The lesions are invasive.[1013]
Airway obstruction, pharyngitis, and fever because of enlargement of adenoids and
tonsils. This is due to florid lymphoid hyperplasia. Histologic findings include florid follicular
hyperplasia, follicular lysis, an attenuation of the mantle zone, and presence of multinucleated
giant cells.[830]
Sinusitis may result from parasitic infections, including those caused by Microsporidium,
Cryptosporidium, and Acanthamoeba. Patients with these infections typically are late in the
course of AIDS with a CD4 count less than 20/µL and the presence of other opportunistic