A 50-year-old male with recent onset asthma develops a non-axial proptosis of the left side. His blood profile shows a slightly raised eosinophil count but is otherwise OK. He undergoes a biopsy of the mass.
1. What is seen in Figs 1 and 2?
2. What is seen in the centre of Fig 3?
3. What does Fig 4 show?
4. This is a CD68 stain. What other stains should be utilised when working up this type of case?
5. What is the differential diagnosis?
1. Fomay cells-histiocytic between the extraocular muscle fibres.
2. Touton giant cell.
3. A recative lymphoid aggregate.
4. Pan-cytokeratin to exclude metastatic clear cell carcinomas, PAS for Whipple’s, ZN for mycobacteria.
5. The differential includes:
AOX-Adult onset xanthogranuloma
AAPOX-adult onset asthma and periocular xanthogranuloma
ECD-Erdheim Chester disease.
Xanthogranulomatous variant IgG4 disease.
In this case the diagnosis was AAPOX.