I'm not an expert, but my husband has been fighting rectal cancer for almost 4 years. Here's my take; hope others will correct me if I'm wrong.
"Multiple non-bleeding diverticula were seen in the descending colon and sigmoid colon. Diverticulosis appeared to be of moderate severity."Diverticulosis means little bulges or pouches in the colon. I think they are pretty common, especially in older folks. Probably unrelated to the mass, I would guess it's more a case of the doctor making note of what s/he saw. If the pouches get infected, that's called diverticulitis, which can require antibiotics and/or surgery, but the report doesn't note evidence of that.
"An ulcerated bleeding 10 cm mass of malignant appearance was found in the anus and rectum. The mass caused a partial obstruction. The scope traversed the lesion. Large ulcered apple core lesion from dentate line to 10 cms. With lumen decreased to 1 cm. Multiple cold forceps were performed for histology. "
10 cm mass = A little less than 4 inches. There are some sites out there that will show foods or fruits to give an idea of tumor sizes, but based on the definition of apple core lesion that I found (see below), I would guess that measurement is the length of the mass.
Apple core lesion = Circumferential, as opposed to a perfectly round mass that grows from a single spot. First image on this page may make that easier to visualize:
https://radiologykey.com/colorectal-cancer-7/Ulcerated/ulcered = Surface is kind of angry and inflamed, irritated, probably not perfectly smooth.
Malignant appearance = In the doctor's opinion, the mass looks cancerous.
Partial obstruction = The mass was large enough to cause a backup of fecal matter, but did not completely prevent waste from getting through.
Traversed the lesion = They were able to get the scope beyond the mass, which I would assume means they visualized the rest of his colon.
Dentate line = The mass starts low in the anus, right at the dentate line,and proceeds upward for 10 cm. Drawing for reference here:
http://www.researchgate.net/figure/A-sc ... _266625536Lumen decreased to 1 cm = I think this means the mass is reducing the diameter of the rectum to 1 cm, which would be in keeping with the observation of "partial obstruction."
Cold forceps for histology = Forceps are a surgical tool, kind of a fancy tweezer. The doctor used them to take several samples of the mass, which were sent for examination under a microscope to determine whether the mass is cancerous.
I hope this is helpful. Sorry that you have to be on this forum, but it is a great source of information and support.