Page 62 - Differential Diagnosis in Small Animal Cytology, The Skin and Subcutis

Inflammatory Lesions
49
Pearls and Pitfalls
VetBooks.ir • Xanthoma and panniculitis cannot be easily differentiated cytologically. The features
reported in the table below can be used as a guideline to differentiate these two forms.

Panniculitis Xanthoma
Frequency Relatively frequent Rare
Clinical manifestation Subcutaneous nodules, often solitary or Multiple pale yellow to white
occasionally multiple papules, plaques, or nodules
Localization in tissue Subcutis Dermis
Presence of adipocytes Often present Often absent (unless incidental
on cytology aspiration of the subcutaneous
fat occurs)

• Cytochemical stains may be used to confirm the presence of lipid-laden macrophages.
With Oil Red O, lipid material stains bright red.

Fig. 6.16. Cat. Xanthoma. Activated macrophages are present. They contain numerous punctate clear vacuoles
(lipids). Wright-Giemsa. (Courtesy of Tracy Stokol, Cornell University, USA.)
Further reading

Bajajee, K.H., Orandle, M.S., Ratterree, W., Bauer, R.W. and Gaunt, S.D. (2011) Idiopathic solitary cutaneous
xanthoma in a dog. Veterinary Clinical Pathology 40(1), 95–98.