Cell-in-cell image These cell-in-cell figures are observed when squamous cells form swirls, like in onion bulbs. Cells in the middle are frequently keratinized. They may be seen in smears from non-neoplastic squamous epithelium (benign epithelial pearls) but more frequently in well differentiated and keratinised squamous cell carcinoma and some intraepithelial lesions (malignant squamous pearls).