Other / Other / MRI

Benign lymphoepithelial lesions

HIV-positive patients presenting with parotid gland enlargement, typically without AIDS-defining illness; occurs in approximately 5% of the HIV population and is associated with cervical lymphadenopathy and nasopharyngeal lymphofollicular hyperplasia.

Key Images

Image

Image 2

Look For First
  • Mixed solid and cystic enlargement of the parotid glands, typically bilateral in ~20% of cases
  • Multiple small septations within cystic spaces on ultrasound (rather than simple cysts)
  • Small mural nodules within the cystic lesions (seen in 40% of cases)
  • Associated cervical lymphadenopathy and nasopharyngeal adenoidal hyperplasia
Key Image Findings
  • Well-circumscribed cystic spaces within the parotid gland that appear mixed solid-cystic on cross-sectional imaging.
  • Thin rim enhancement on postcontrast MRI surrounding the cystic lesions.
  • Ultrasound reveals multiple small septations within the 'cystic' spaces, which appear simple on CT or MRI but have complex internal architecture on sonography.
  • Small mural nodules present in approximately 40% of cases on ultrasound examination.
  • Vascular pedicle may be identified entering the cystic region, representing feeding vessels.
  • Lesions most commonly affect the parotid gland; rarely involve submandibular or sublingual glands.
  • Associated findings include prominent nasopharyngeal adenoidal tissue (seen in 35% of HIV-positive patients), posterior triangle lymphadenopathy, and abnormal bone marrow signal.
  • Pathophysiology involves dilatation of intraglandular ducts due to obstruction from lymphoid hypertrophy rather than true cyst formation.
Differential Diagnosis
  • First branchial cleft cyst: typically presents as a single well-defined cyst lateral to the mandible, lacks the multiseptated architecture and associated systemic lymphadenopathy seen with benign lymphoepithelial lesions.
  • Warthin tumor: shows solid components with enhancement and occurs in smokers; lacks the multiple septations and mural nodules characteristic of benign lymphoepithelial lesions.
  • Sjögren disease: causes similar lymphoepithelial sialadenitis but presents with autoimmune serologies and different clinical context than HIV disease.
  • Sialocele: results from ductal injury or obstruction but lacks the associated cervical lymphadenopathy and nasopharyngeal findings typical of benign lymphoepithelial lesions.
  • Sarcoidosis: causes parotid enlargement with systemic findings, but lacks the characteristic multiseptated cystic architecture with mural nodules.
  • Necrotic intraparotid lymph nodes: may appear cystic but show different morphology and lack the rim enhancement pattern seen with benign lymphoepithelial lesions.
Discussion

Benign lymphoepithelial lesions are not an AIDS-defining illness and occur typically in HIV-positive patients without AIDS, making the alternative term 'AIDS-related parotid cysts' misleading.

The lesions arise from dilatation of intraglandular ducts secondary to obstruction caused by lymphoid hypertrophy, not from true cyst formation.

Ultrasound is superior to CT and MRI for characterizing these lesions because it reveals the true multiseptated nature and mural nodules that may appear simpler on cross-sectional imaging.

The 40% incidence of mural nodules is an important imaging finding that helps distinguish benign lymphoepithelial lesions from simple parotid cysts.

Associated findings of nasopharyngeal adenoidal tissue, cervical lymphadenopathy, and bone marrow signal abnormalities indicate systemic lymphoid hyperplasia and support the diagnosis.

Histopathologically, benign lymphoepithelial lesions represent a non-specific finding that can occur in both HIV-associated salivary gland disease and Sjögren disease, requiring clinical correlation for accurate diagnosis.

Reporting Pearls

Describe benign lymphoepithelial lesions as "mixed solid and cystic parotid enlargement with multiseptated appearance and thin rim enhancement" and specifically note the presence of mural nodules (if seen on ultrasound) and associated cervical lymphadenopathy; document whether bilateral involvement is present, as this occurs in approximately 20% of cases.

Pitfalls
  • Misinterpreting benign lymphoepithelial lesions as simple parotid cysts on CT or MRI without ultrasound correlation, thereby missing the characteristic multiseptated architecture and mural nodules.
  • Failing to recognize this as an HIV-associated entity and missing the clinical context; the alternative misleading term 'AIDS-related parotid cysts' may lead to incorrect staging assumptions.
  • Not assessing for associated findings such as nasopharyngeal adenoidal hyperplasia, cervical lymphadenopathy, and bone marrow abnormalities, which are important diagnostic clues.
  • Confusing benign lymphoepithelial lesions with Sjögren disease or other causes of parotid sialadenitis; clinical history and serologies are essential for differentiation.
Source: Reference source

Secondary Links

HomeExtramucosal DiseaseAnatomyGeneral Resources