Keratin pearls (Fig 4F) were seen in 13(20.6%) cases of PA in the current study, most of which are of classic type (n=11, 84.6%).
The central cells showed stellate reticulum like appearance with some cells showing squamous metaplasia and numerous
keratin pearls (Figure 5).
(7,14) Another characteristic feature of this form of neoplasia includes infiltrative cords of moderately undifferentiated to poorly differentiated squamous cells that frequently form central cores of laminated keratin (
keratin pearls), as seen in the infraorbital sinus of this bird.
Prominent
keratin pearls and intercellular bridges were evident in histology, which are characteristic of squamous cell differentiation (Figure 4).
SCC is defined as "a malignant epithelial neoplasm exhibiting squamous differentiation as characterized by the formation of
keratin pearls and/ or presence of intercellular bridges" [2-4,12].
Histopathology was characterized by presence of proliferating squamous cells forming cell nests and
keratin pearls (Fig.
Excisional biopsy of the lesion over the lip showed
keratin pearls, malignant cells invading the dermis arranged in cords and sheets.
The epithelial cells are seen in the form of cords or groups with one area showing formation of
keratin pearls with in the connective tissue (Figure 3), suggesting the development of Squamous Cell Carcinoma from the retromolar area.
Additionally, keratinized epithelial cells and moderate numbers of
keratin pearls were observed.
