GI Path Online
Pathology of the Intestinal Polyps -
5 interesting polyps of the intestine.
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Polyps of the
intestine are very common specimen and represent a large proportion of
the practising pathologists' workload in any part of the world.
There are many types of intestinal polyps and accurate histological assessment is important to ensure the accurate diagnosis and appropriate management of the patients.
Any localized lesion raised above an epithelial surface may be regarded as a polyp.
Polyps can arise from mucosal and submucosal tissues.
Polyps can be formed as a result of abnormal mucosal maturation, inflammation or architecture.
These polyps are non-neoplastic and do not have malignant potential per se.
Examples- Hyperplastic polyps ; Juvenile polyps ; Peutz Jeghers polyps.
The polyps that arise as a result of proliferative dysplasia are termed as adenomatous polyps or adenomas.
They are true neoplastic lesions and are precursors of carcinoma.
In addition to adenomatous polyps a number of other neoplasms such as carcinoid tumour, primary lymphoma, stromal tumour, Kaposi's sarcoma and occasionally carcinoma can present as colorectal polyps.
The term polyposis should be restricted to recognizable syndromes in which the primary feature is the presence of multiple polyps.
Diagnosis of Pathology Quiz Cases:
1) Pathology of Juvenile Polyps:
- Focal hamartomatous malformations of mucosal elements.
- Age: Common between 1-7yrs.
- Sporadic or associated with Juvenile Polyposis Syndrome.
- 80% located in the rectum
- Single spherical or multilobated masses.
- May ulcerate, undergo torsion and autoamputation.
- Gross: Cystically dilated spaces with mucinous content.
Microscopic features of Juvenile Polyps:
Abundant lamina propria
Cystically dilated glands
Epithelium lining cyst and surface - normal or hyperplastic.
Dysplasia uncommon in sporadic juvenile polyps.
2) Pathology of Peutz-Jeghers Polyps:
- Hamartomatous polyps.
- Common in the small intestine.
- Large and pedunculated, with firm lobulated contour.
- Solitary polyps may occur.
- Autosomal dominant
- Hamartomatous intestinal polyps and mucocutaneous melanin pigmentation.
- 3 or more Peutz-Jeghers polyps.
- Any number of polyps + family history of Peutz-Jeghers Syndrome.
- Mucocutaneous pigmentation + family history of Peutz-Jeghers Syndrome.
- Any number of Peutz-Jeghers polyps + mucocutaneous pigmentation.
Microscopic features of Peutz-Jeghers Polyps:
- Arborizing network of connective tissue and smooth muscle.
- Surrounds normal abundant glands lined by normal intestinal epithelium.
- Small intestine-goblet and columnar cells in superficial part.
- Paneth and endocrine cells at the base.
- Cytological composition of polyp depends on the location.
- Sloughed off goblet cells - signet cell appearance- mistaken as malignancy.
- Displacement of epithelium - submucosa or beyond- "enteritis cystica profunda" - mistaken for invasive malignancy.
- Dysplasia and malignant change - very rare
3) Pathology of Inflammatory Fibroid Polyps:
- Location: Stomach and small intestine – ileum
- Usually solitary lesion and is noted in adults.
- Symptoms: Obstruction and intussusception
- Response to unknown stimulus - Myofibroblasts, vascular and inflammatory elements.
- Site of previous surgery- trauma may be a factor.
- Early: Solitary and sessile.
- Later: Pedunculated (2-5 cm in diameter).
- Mucosal ulceration
- Dumbell-shaped mass
Microscopic features of Inflammatory Fibroid Polyps:
- Submucosal lesion
- Hyalinized connective tissue.
- Eosinophils and plasma cells.(+)
- Stellate or spindle shaped cells
- Differential diagnosis- Eosinophilic Gastroenteritis
Lymphoid and Lymphomatous Polyposis:
4) Benign lymphoid polyp and polyposis
- Located in rectum
- Occur in children
- Following viral infection.
- In patients with immune deficiency.
- Polypoid lymphoid hyperplasia- defunctioned rectum or colon
- Should be distinguished from ‘malignant lymphomatous polyposis ’.
Microscopic features of Lymphoid and Lymphomatous Polyposis:
- Located in the submucosa
- Sharply defined mass of lymphoid tissue.
- Well developed follicular structure with germinal centres.
- Tingible body macrophages (++).
- Fibrous septa between follicles (+).
- Absence of monotypic pattern with immunoglobulins.
5) Malignant Lymphomatous Polyposis
- Mantle cell lymphoma
- Occurs in adults. Presents with diarrhea.
- Multiple small polyps.
- Involvement of ileo-caecal region is prominent.
- Endoscopically - mimic other polyposis syndromes.
- Histological differential diagnosis - Benign lymphomatous polyposis and primary low-grade B-cell lymphoma of mucosa associated lymphoid tissue.
- Surgery is contraindicated.
Treatment - chemotherapy.
- Prognosis - poor
|Classification of polyps and polyposis syndromes of intestine:|
|Adenoma||neoplasia||Familial adeno. polyposis (FAP)|
|Juvenile polyp||hamartoma||Juvenile Polyposis|
|Peutz-Jeghers polyp||hamartoma||Peutz-Jeghers syndrome|
|Hyperplastic polyp||? hypermaturity||Hyperplastic polyposis|
|Inflammatory polyp||inflammation||Inflammatory polyposis|
mucosal prolapse (including inflammatory cloacogenic, cap and
polyps) Inflammatory cap polyps
|mucosal prolapse||Cap polyposis|
|Lymphoid polyp||hyperplasia||Lymphoid polyposis|
|Lymphomatous polyp||neoplasia||Malignant lymphomatous polypsis|
|Inflammatory fibroid polyp||? trauma||Inflammatory fibroid polyposis|
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