Partially ulcerated mucosal fragments show adenocarcinoma composed of irregular infiltrating glands, focal cribriform architecture, and malignant epithelial cells exhibiting moderate nuclear pleomorphism, hyperchromatic enlarged nuclei, conspicuous nucleoli, and moderate eosinophilic cytoplasm. Frequent mitotic figures are identified, and tumor groups are set within a desmoplastic stroma.
Immunostaining was done with appropriate positive and negative controls and revealed: retained nuclear expression of MLH1, PMS2, MSH2, and MSH6 in tumor cells.
Referred paraffin block for immunostaining of descending colon annular fungating ulcerated mass.
One referred paraffin block.
Descending colon mass, endoscopic biopsy and immunostaining:
Comment: