Description
Clinical History
A 50-year old male underwent a colonoscopy after testing positive for fecal occult blood during a screening test. Colonoscopy revealed a pedunculated tumor in the descending colon, which was later resected.
Pathology
This specimen is the resected segment of descending colon. There is a single dark lobulated mass visible arising from the mucosal surface. It is attached to a stalk which is 4cm in length. Histologically, the mass comprises a core of connective tissue covered with hyperplastic glandular epithelium of colonic type, with focal nuclear atypia. This is an example of a tubular colonic adenoma.
Further Information
Colorectal adenomas are intraepithelial neoplasms that characteristically display epithelial dysplasia. They are benign but are precursors to adenocarcinoma. Not all adenomas evolve into adenocarcinoma. They produce polyps (sometimes pedunculated) or sessile lesions or variable size. They occur predominantly in males and are more common in Western countries due to diet and lifestyle. They are present in about 30% of people over the age of 60 years in the West. There is an increased risk in patients with a positive family history of colorectal adenocarcinoma. Regular surveillance colonoscopy in at risk groups with polyp removal reduces incidence of adenocarcinoma. There are three classifications of colonic adenomas based on their architecture: tubular (>75% have a tubular morphology), tubulovillous (25-75% villous morphology) and villous (>75% have villous morphology). Histologically, they may have epithelial dysplasia characterized by nuclear hyperchromasia, elongation and stratification. Tubular adenomas tend to be small, pedunculated polys composed of rounded or tubular glands. Pedunculated adenomas have a slender fibromuscular stalk with blood vessels derived from the submucosa. The stalk is usually non-neoplastic epithelium. The size of the adenoma is the biggest predictor of progression to adenocarcinoma. Progression is rare in adenomas <1cm in diameter. However, up to 40% of lesions larger than 4cm in diameter progress to adenocarcinoma.
Most adenomas are asymptomatic and slow growing. Large polyps may present with symptoms of anemia from occult bleeding. Villous adenomas occasionally secrete large amounts of mucoid protein and/or potassium rich fluid, leading possibly to hypokalemia.
Advantages
- Anatomically accurate and identical to real specimen
- No ethical issues - not real human body parts
- Reasonably priced
- Available within a short lead time
- Reproducible, several identical prints can be used as a classroom set
- Can be produced in different sizes to cater for the needs of the teacher
Human Cadavers
- Access to cadavers can be problematic. Many countries cannot access cadavers for cultural and religious reasons
- Cadavers cost a lot money
- High cost for establishing your own plastination suite
- Wet specimens cannot be used in uncertified labs
- Dissection of cadavers is a lot of staff time and that is a cost
- Storage of cadaver material needs special refrigeration etc. which has coast
- If you want another specimen you have to start all over again
Plastinates
- Costs
- Ethical issues
- Timeframe for plastination process
- Many countries do not allow their importation
- One of a kind
Superior 3D print results compared with conventional methods
- Vibrant color offering with 10 million colors
- UV-curable inkjet printing
- High quality 3D printing that can create products that are delicate, extremely precise and incredibly realistic
Clear Support Material
- To avoid breakage of fragile, thin, and delicate arteries, veins or vessels, a clear support material is printed on such spots. This makes the models robust and can be handled by students easily.
