General pathology lecture 6 adenoma

1. ADENOMA
Lecture No.6

2. What is an adenoma?
•Adenoma is a tumor of glandular epithelium in
which the cells of the tumor are arranged in a
recognizable glandular structure.
•Adenoma may cause excess secretion by the
affected gland, such as acidophilic pituitary
adenoma resulting in an excess of growth
hormone
•Adenomas are derived from the ducts and acini of
glands, although the name is also used to cover
simple tumors arising in solid epithelial organs.

3. Difference Between Adenomas and
Malignant Tumors
•An adenoma may form in a similar way as a
malignant or cancerous tumor.
•A major difference between malignant tumors
and adenomas is that adenomas do not
metastasize or spread to other organs or tissues.
•Sometimes, however, adenomas develop into
malignancies. When this happens, the newly
malignant adenoma is called adenocarcinoma.

4. Symptoms related to Adenomas:
•Symptoms related to adenomas vary widely.
•Women the use oral contraceptives may be at
increased risk of liver adenomas.
•There is fever, chills, shortness of breath and a
bloody cough in lung adenoma.
•Fibroadenoma typically causes no symptoms and
lump may be so small that the individual is
unable to detect it.
•Colon adenomas are inheritable.

5. Types of Adenoma
•Papillary adenoma
•Pleomorphic adenoma
•Villous adenoma
•Tubular adenoma
•Sessile adenoma
•Pedunculated adenoma
•Cystadenoma
•Sebaceous adenoma

6. Sebaceous Adenoma
It is a small, slow-growing tumor that typically
forms in the sebaceous , or oil-producing glands
of the skin.
They grow mostly on the scalp, face and neck, but
have been known to appear on other parts of the
body.
Both men and women can develop these tumors,
which generally appear at 50 years of age.
While not serious, they can sometimes indicate
Muir-Torre syndrome (MTS), a serious genetic
illness.

7. Papillary adenoma
•A benign epithelial tumor in which the membrane
liming the glandular tissue form papillary
processes that project into the alveoli or grow out
of the surface of a cavity.
•Also called adenolymphoma
•Contains intracystic papillae.
•As in hollow viscus, the proliferating epithelium
may be heaped to form papillolas and the tumor
becomes a papillary cystadenoma
•They are common in the ovary.
•May be few and sessile or pedunculated with
fronds often complex in structure

8. Pleomorphic Adenoma
•Pleomorphic adenoma constitutes about 60% of
parotid tumors, which manifests as a salivary
gland mass in young and middle-aged adults
•They have varying patterns of epithelial cells
(acini, trabeculae, sheet and myoepithelial cells)
•They are usually tan-gray and well-circumscribed;
some have extensions into adjacent tissue.
•Pleomorphic adenoma transform s into an
aggressive carcinoma.

9. Villous adenoma
•These polyps constitute 1/10
th
of colonic adenomas
and are found predominantly in the rectosigmoid
region.
•They are typically large, broad-based, elevated
lesions that grossly display a shaggy, cauliflower-
like surface.
•Villous adenoma commonly contain foci of
carcinoma
•Microscopically, villous adenomas are composed
of thin, tall, finger-like processes that superficially
resemble the villi of the small intstines.

10. Villous Adenoma

11. Tubular Adenoma
•These polyps constitute 2/3s of benign large
bowel adenomas.
•It is the most common neoplastic polyp of the
colon and which is most frequent in the rectum
•They are typically smooth-surfaced spheres,
usually less than 2 cm in diameter, which are
often attached to the mucosa by a stalk.
•Some tubular adenomas, particularly the smaller
ones, are sessile.
•Microscopically, tubular adenoma exhibits closely
packed epithelial tubules, which may be uniform
or may be irregular and excessively branched.

12. Tubular Adenoma

13. Tubulovillous adenoma
•They manifest both tubular and villous features.
•These are polyps with more than 20% and less
than 80% villous architecture.
•They tend to be intermediate in distribution and
size between the tubular and villous forms.
•Tubulovillous polyps are also intermediate
between tubular and villous adenoma in the risk
of invasive carcinoma

14. Types of Colorectal Adenoma according to
Microscopic Features:
•Villous adenoma: elongated pattern of the
abnormal glands. Cells form finger-like growths.
It is most likely to become malignant or
cancerous.
•Tubular adenoma: have glands with branched
structure. It is less likely to become malignant.
Most adenomas are of this type.
•Tubulovillous adenoma is a combination of
the two. Seen less often.

15. Sessile adenoma
•Polyps that are attached by a base rather than by
a stalk or a peduncle.
•Sessile adenomas are structures with large, broad
bases.

16. Cystadenoma
•Cystadenoma or cystic adenomas are benign
tumors which grows into the subjacent connective
tissue, with progressive budding of the epithelium
that results in new acini which become nipped off
from the parent acini
•Types of Cystadenoma:
•Serous Cystadenoma – makes up 25% of all
ovarian tumors. Most of them are bilateral.
•Mucinous Cystadenoma – accounts for 20%of all
ovarian tumors. It can reach a very large size and
is typically multilocular, 25% bilateral.

17. Mucinous Cystadenoma

18. Pedunculated adenoma
•Pedunculated polyps has a stemlike connection or
having a stalk
•Pedunculated polyps vary in size from a few mm
to 3 or more cms.
•Microscopically, there is proliferation of tubular
colonic glands, with varying amounts of dysplasia
•Few have frankly malignant change

19. Adenomatous polyposis coli (APC)
•An inherited disorder characterized by the
development by myriad polyps in the colon
beginning in late adolescence or early adulthood.
•The gene is located on chromosome 5
•Untreated, the condition may lead to colon
cancer.

20. APC

21. Glandular Adenomas can be diagnosed by:
•Colonoscopy: Doctors insert a probe containing
a camera through the anus in order to visualize
the inner surface of the colon and rectum. Any
tissue jutting out abnormally is removed during
the procedure and then sent to a pathologist for
microscopic analysis.
•Other imaging techniques, such as CT Scan or an
Air-contrast barium enema can be done.

22. Three Types of Adenomas that can be seen during
Colonoscopy:
•Sessile adenoma are large structures with broad
bases.
•Flat adenomas have also large bases connected to
the inner wall of the GIT, but these growths
typically have a diameter at least 2 times longer
than the height.
•Pedunculated adenomas are mushroom-shaped
with a narrow stalk connecting the inner
intestinal surface to the growth.

23. Fibroadenoma – Female breast

24. Breast Adenoma
•A breast adenoma or fibroadenoma is a typical
lump of few cms. in diameter, but may grow if a
woman becomes pregnant.
•The existence of a breast adenoma is not a
precursor to developing breast cancer, although it
has been found out to indicate a slightly higher
risk for developing malignant tumors later in life.
•Removal by surgery may be necessary if a tumor
associated with breast adenoma continues to
grow.

25. FIBROADENOMA

26. Next Meeting
•Next meeting
•Quiz on Adenoma
•Assignment: Read on Neoplasms