Angiolymphoid hyperplasia with eosinophilia simulating lymphadenopathy

Area of Science:

• Vascular Pathology
• Immunohistochemistry
• Electron Microscopy

Background:

• Angiolymphoid hyperplasia with eosinophilia (AHE) is a rare condition.
• AHE typically presents as cutaneous papules or nodules, often on the head and neck.
• Inguinal swellings simulating lymphadenopathy are an unusual presentation of AHE.

Observation:

• A case of AHE with eosinophilia presented with recurrent inguinal swellings.
• Light microscopy, electron microscopy, and immunohistochemistry were utilized for tissue examination.
• Electron microscopy identified atypical endothelial cells with cytoplasmic filaments and bizarre Weibel-Palade bodies.

Findings:

• Factor VIII related antigen was positive in a subset of atypical endothelial cells.
• Absence of lysozyme and alpha 1 antitrypsin staining argued against a histiocytic origin.
• Lymphoid and plasma cell proliferation showed a polytypic immunoglobulin staining pattern.
• An unusual reticular IgE staining pattern was noted in lymphoid follicles.

Implications:

• This case highlights an atypical presentation of AHE, emphasizing the importance of considering AHE in the differential diagnosis of inguinal swellings.
• The findings support the endothelial cell origin of AHE and provide further insight into its pathogenesis.
• Understanding the immunophenotype of AHE is crucial for accurate diagnosis and management.