A polyp found in the descending colon and removed as a single fragment (H&E attached)
WHAT IS THE DIAGNOSIS
a) Tubular adenoma
Yes but you are only partly correct!
b) Tubulovillous adenoma
No way, this is a LST-NG!!!
c) Villous adenoma
Absolutely not - there are no villi!!!
d) Sessile serrated lesion
Looks like it but histology doesn't!
e) Malignant polyp
This is a LST-NG type of lesion (laterally spreading tumour of the non-granular type). They are always TA's (tubular adenomas) and often (but usually not), harbour HGD or cancer. I guess that we can't really be sure about the crypt pattern as this is a non-magnified image. However, looking at the histology slide with narrow crypts, I expect that the crypt pattern is probably IIIs (small round crypts) which goes with TA+HGD. Must admit that I was surprised to find invasive cancer and LVI (lymphovascular invasion) in a small lesion such as this! The last image shows clusters of malignant cells within lymphatics. Of all the 'markers' to suggest that the patient needs surgery, LVI is the most important!