Page 136 - Differential Diagnosis in Small Animal Cytology, The Skin and Subcutis

Epithelial Tumours
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8.8 Diagnostic Algorithms
VetBooks.ir As discussed at the beginning of this chapter, on cytology some cutaneous epithelial tumours can

share similar cellular and morphological features. Lesions that may show overlapping cytological
findings include follicular cysts and tumours, sweat gland tumours and basal cell tumours. The
following algorithms may help to refine the final diagnosis.

Anucleated squames only

Ghost cells Polygonal squames Amorphous keratinized material
and/or liquid keratin
material

Pilomatricoma Trichoepithelioma Follicular cyst: isthmus

Follicular cyst: IKA
matrical
Follicular cyst:
infundibulum

Fig. 8.38. Diagnostic algorithm to be used if only anucleated squamous epithelial cells exfoliate upon aspiration.

Anucleated squames + nucleated epithelial cells

Cuboidal Columnar epithelial Epithelial cells show progressive
epithelial cells maturation from cuboidal to
cells anucleated squamous epithelial
cells

Trichoepithelioma Most likely sweat Most likely IKA
Pilomatricoma gland tumour
IKA
Sweat gland tumour

Fig. 8.39. Diagnostic algorithm to be used when both anucleated squamous epithelial cells and nucleated
epithelial cells are present.

Nucleated epithelial cells only

Cuboidal Ribbon-like Duct-like Columnar epithelial
epithelial cells arrangement arrangement cells

Trichoblastoma

Sweat gland tumour

Basal cell tumour
Fig. 8.40. Diagnostic algorithm to be used when only nucleated epithelial cells are present.