Friday, March 30, 2007

Lymphoepithelial cysts in the setting of known HIV


Additional clinical history: Patient has recently tested HIV positive


Findings

Cystic replacement of the parotid glands without evidence of solid enhancing component or periglandular inflammation. Borderline enlarged Level 2 cervical lymph nodes.

Differential diagnosis:
- Treated lymphoma
- Infection / abscess including tuberculosis and atypical mycobacterium
- Brachial cleft cyst
- Abcess
- Warthin gland tumor
- Sjogren's syndrome
- Lymphoepithelial cysts


Diagnosis: Lymphoepithelial cysts in the setting of known HIV


Key points

Development of parotid gland lymphoepithelial cysts occurs early in HIV disease, often with coexistent generalized cervical lymphadenopathy. Because of this, HIV testing should be performed if a patient presents with lymphoepithelial cysts, which occur exclusively in the parotid glands. The cysts are painless and slow growing, with predominantly bilateral involvement. Lesions are usually multicystic with superficial involvement.

During embryonic development, lymph tissue is included in the parotid capsule. This lymphoid tissue is then vulnerable to the HIV virus. Patients with parotid cysts and cervical lymphadenopathy usually have CD4 levels below 500/ml. Pathogenesis of HIV related lymphoproliferative changes of the parotid remains unclear, but is likely related to an exaggerated immunological response to infection.


Radiology

CT/US/MRI: Bilateral superficial parotid cysts with possible associated adenopathy and lymphoid hyperplasia.

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