case_images: PMC10202599_01
case_images: Clinical picture of the midforehead depicting an erythematous scaling papule in a background of atrophic scar.
case_images: CRIPA2023-3378044.001.jpg
case_images: PMC10202599_01_CRIPA2023-3378044.001.jpg
case_images: fig1
case_images: 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).
case_images: 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).
case_images: CRIPA2023-3378044.002.jpg
case_images: PMC10202599_01_CRIPA2023-3378044.002.jpg
case_images: fig2
case_images: A moderate lymphocytic infiltrate was observed along the base of the tumor (Figure 2).
case_images: 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).
case_images: CRIPA2023-3378044.003.jpg
case_images: PMC10202599_01_CRIPA2023-3378044.003.jpg
case_images: fig3
case_images: 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)).