PMC10202599_01
Clinical picture of the midforehead depicting an erythematous scaling papule in a background of atrophic scar.
CRIPA2023-3378044.001.jpg
PMC10202599_01_CRIPA2023-3378044.001.jpg
fig1
On examination, an erythematous scaly papule was identified above the right eyebrow, measuring 0.4 cm in a background of hypopigmented, slightly atrophic scar (Figure 1).
Histopathologic analysis. (a) Superficial skin ulcer associated with lobules and strands of atypical squamous cells infiltrating the dermis. Chronic inflammatory infiltrate is noted at the base of the tumor. H&E (original magnification x20). (b) Moderate to poorly differentiated squamous cells with minimal keratinization are observed. H&E (original magnification x200). (c) Tumor depicting squamous and signet-ring-like cell components. H&E (original magnification x200). (d) Signet-ring-like cells displaying displaced nuclei with clear cytoplasm and occasional eosinophilic cytoplasmic inclusions. H&E (original magnification x400).
CRIPA2023-3378044.002.jpg
PMC10202599_01_CRIPA2023-3378044.002.jpg
fig2
A moderate lymphocytic infiltrate was observed along the base of the tumor (Figure 2).
Immunohistochemical findings: (a) CK5/6 stain depicting positive staining in the squamous and the signet ring-like cells (original magnification x200); (b) beta-catenin stain showing weak and incomplete membranous staining in tumor cells (original magnification x400); (c) CDX2 stain revealing weak to moderate positive nuclear staining in the tumor (original magnification x400); (d) P63 stain highlighting nuclei of tumor cells (original magnification x200).
CRIPA2023-3378044.003.jpg
PMC10202599_01_CRIPA2023-3378044.003.jpg
fig3
The immunohistochemical studies revealed two types of tumor cells positive for P63, CK5/6, and P53 (positive in 35-40% of tumor cells) and weak to moderately positive for CDX2 (Figures 3(a), 3(c), and 3(d)) while negative for P16, CK7, CK20, and CD68 stains. Heterogeneous, incomplete membranous staining for beta-catenin was observed in more than 50% of tumor cells (Figure 3(b)).