Evidence for colorectal sarcomatoid carcinoma arising from tubulovillous adenoma

Figure 2 Histology of the rectal biopsy using HE stains. A: Tubulovillous adenoma and underlying spindle cell tumor. The aggressive spindle cell lesion infiltrates directly underneath the adenoma (× 10); B: A higher magnification view of the adenomatous component (× 20). High-grade spindle cell lesion (× 40) showing: C: Cigar shaped nuclei, nuclear pleomorphism, a high mitotic rate; D: Tumor necrosis; E: Smooth muscle-like spindle sheets of cells in the sarcomatoid component (× 40).