Inflammatory fibroid polyp, abbreviated IFP, is a benign abnormal growth of tissue projecting into the lumen of the gastrointestinal tract.

Almost all women present with uterine fibroids, approximately 76% with dermal manifestations and 10-16% with renal tumors.

The uterine fibroids tend to occur at younger age and larger and more numerous than in general population. They may be distinguishable from sporadic fibroids by special histological features such as prominent nucleoli with perinucleolar halos.

The skin presentation is of asymmetrical, reddish-brown nodules or papules with a firm consistency, predominantly located on the limbs (multiple cutaneous leiomyoma), although they may occur anywhere, including the face. The lesions, which are typically painful and most often present during the third decade of life, are piloleiomyomata—a benign smooth muscle tumour arising from the arrectores pilorum muscles of the skin. These tumours may also arise in the tunica dartos of the scrotum and the mammillary muscle of the nipple (genital leiomyoma), the smooth muscle of blood vessels (angioleiomyoma) and the lung (pulmonary lymphangioleiomyomatosis). A pseudo-Darier sign may be present.

The renal cell carcinoma tends to be of the papillary (type 2) form and tends to occur more commonly in women than men with this syndrome. These cancers present earlier than is usual for renal cell carcinomas (typically in the twenties and thirties) and to be at relatively advanced stages at presentation. Tumours have rarely been reported in children. These tumours occur in ~20% of those with this mutation suggesting that other factors are involved in the pathogenesis.

IFPs consist of spindle cells that are concentrically arranged around blood vessels and have inflammation, especially eosinophils.

They may have leiomyoma/schwannoma-like areas with nuclear palisading.

They typically stain with CD34 and vimentin, and, generally, do not stain with CD117 and S100.

The endoscopic differential diagnosis includes other benign, pre-malignant and malignant gastrointestinal polyps.

Uterine fibroids are leiomyomata of the uterine smooth muscle. As other leiomyomata, they are benign, but may lead to excessive menstrual bleeding (menorrhagia), often cause anemia and may lead to infertility.

A rare form of these tumors is uterine lipoleiomyoma—benign tumors consisting of a mixture of adipocytes and smooth muscle cells. Uterine lipoleiomyomata have been observed together with ovarian and other pathologies and some of them may develop into liposarcoma. These tumors are monoclonal, and non-random chromosomal abnormalities have been seen in 40% of the tumors.

Mesenchymal neoplasms of the gallbladder are rare and in particular leiomyomas of the gallbladder have been rarely reported, all of them in patients with immune system disorders. Although, recently, a case was reported in absence of associated immunodeficiency at Monash Hospital in Melbourne Australia in a healthy 39-year-old woman with no symptoms.

Benign metastasizing leiomyoma is a rare condition characterized by the growth of uterine leiomyoma in the other regions especially the lungs.

A cervical polyp is a common benign polyp or tumor on the surface of the cervical canal. They can cause irregular menstrual bleeding or increased pain but often show no symptoms.

Most patients with fundic gland polyps (FGPs) do not have any symptoms, and the diagnosis is made on gastroscopy done for other reasons. Retrospective analysis of patients with sporadic FGPs shows that a high percentage do have symptoms, but that this is more likely to be related to the underlying disease responsible for the polyposis. These symptoms include:

- epigastric pain

- nausea

- vomiting

- weight loss

The polyps on endoscopy are usually tiny, numerous and sessile, and usually scattered throughout the fundus of the stomach, where parietal cells are more numerous. They have the same colour as the gastric mucosa, and never have a stalk.

When the polyps are biopsied, the pathology typically shows shortened gastric pits, and both superficial and deep cystic lesions in the fundic glands, lined by all three types of cells of acid-producing mucosa: mucous, parietal and chief cells. As sometimes parietal cell hyperplasia may develop deep dilations of gland, one should be really strict in the diagnosis of FGPs (i.e. the presence of deep and superficial dilations). Infrequently, the two lesions may coexist. Foci of dysplasia can sometimes be seen.

SSAs, generally, are asymptomatic. They are typically identified on a colonoscopy and excised for a definitive diagnosis and treatment.

A polyp is an abnormal growth of tissue projecting from a mucous membrane. If it is attached to the surface by a narrow elongated stalk, it is said to be "pedunculated". If no stalk is present, it is said to be "sessile". Polyps are commonly found in the colon, stomach, nose, ear, sinus(es), urinary bladder, and uterus. They may also occur elsewhere in the body where mucous membranes exist like the cervix, vocal folds, and small intestine. Some polyps are tumors (neoplasms) and others are nonneoplastic (for example, hyperplastic or dysplastic). The neoplastic ones are generally benign, although some can be premalignant and/or concurrent with a malignancy.

Age of onset is variable. The term 'Juvenile' in the title of Juvenile polyposis syndrome refers to the histological type of the polyps rather than age of onset.

Affected individuals may present with rectal bleeding, abdominal pain, diarrhea or anemia. On colonoscopy or sigmoidoscopy polyps that vary in shape or size are present. The polyps can be sessile or pedunculated hamartomatous polyps.

The most common general classification is:

- hyperplastic,

- neoplastic (adenomatous & malignant),

- hamartomatous and,

- inflammatory.

SSAs are diagnosed by their microscopic appearance; histomorphologically, they are characterized by (1) basal dilation of the crypts, (2) basal crypt serration, (3) crypts that run horizontal to the basement membrane (horizontal crypts), and (4) crypt branching. The most common of these features is basal dilation of the crypts.

Unlike traditional colonic adenomas (e.g. tubular adenoma, villous adenoma), they do not (typically) have nuclear changes (nuclear hyperchromatism, nuclear crowding, elliptical/cigar-shaped nuclei).

These are polyps which are associated with inflammatory conditions such as Ulcerative Colitis and Crohns disease.

Juvenile polyposis syndrome is a syndrome characterized by the appearance of multiple juvenile polyps in the gastrointestinal tract. Polyps are abnormal growths arising from a mucous membrane. These usually begin appearing before age 20, but the term "juvenile" refers to the type of polyp, not to the age of the affected person. While the majority of the polyps found in Juvenile Polyposis Syndrome are non-neoplastic, hamartomatous, self-limiting and benign, there is an increased risk of adenocarcinoma.

Solitary juvenile polyps most commonly occur in the rectum and present with rectal bleeding. The World Health Organization criteria for diagnosis of juvenile polyposis syndrome are one of either:

1. More than five juvenile polyps in the colon or rectum; or

2. Juvenile polyps throughout the gastrointestinal tract; or

3. Any number of juvenile polyps in a person with a family history of juvenile polyposis.

Intravenous leiomyomatosis is a rare condition seen exclusively in women in which leiomyomata, benign smooth muscle tumors, are found in veins. The masses are benign-appearing but can spread throughout the venous system leaving the uterus and even cause death when growing into the heart from the IVC. While the possibility that these arose de novo from the smooth muscle in the blood vessel wall was considered, chromosomal analysis suggests a uterine origin. Intravenous leiomyomata are usually but not always associated with uterine fibroids, and tend to recur.

This condition is related to benign metastasizing leiomyoma, in which the masses appear in more distant locations such as the lung and lymph nodes.

The colorectal adenoma is a benign glandular tumor of the colon and the rectum. It is a precursor lesion of the colorectal adenocarcinoma (colon cancer).

Some morphological variants have been described:

- tubular adenoma

- tubulovillous adenoma

- villous adenoma

- sessile serrated adenoma (SSA)

Reed’s syndrome (or familial leiomyomatosis cutis et uteri) is a rare inherited condition characterised by multiple cutaneous leiomyomas and, in women, uterine leiomyomas. It predisposes for renal cell cancer, an association denominated hereditary leiomyomatosis and renal cell cancer, and it is also associated with increased risk of uterine leiomyosarcoma. The syndrome is caused by a mutation in the fumarate hydratase gene, which leads to an accumulation of fumarate. The inheritance pattern is autosomal dominant.

Fundic gland polyposis is a medical syndrome where the fundus and the body of the stomach develop many polyps. The condition has been described both in patients with familial adenomatous polyposis (FAP) and attenuated variants (AFAP), and in patients in whom it occurs sporadically.

Endometrial intraepithelial neoplasia (EIN) is a premalignant lesion of the uterine lining that predisposes to endometrioid endometrial adenocarcinoma. It is composed of a collection of abnormal endometrial cells, arising from the glands that line the uterus, which have a tendency over time to progress to the most common form of uterine cancer—endometrial adenocarcinoma, endometrioid type.

From early adolescence, patients with this condition gradually (and much of the time 'silently') develop hundreds to thousands of colorectal polyps (and sometimes polyps elsewhere)—small abnormalities at the surface of the intestinal tract, especially in the large intestine including the colon or rectum. These may bleed, leading to blood in the stool. If the blood is not visible, it is still possible for the patient to develop anemia due to gradually developing iron deficiency. If malignancy develops, this may present with weight loss, altered bowel habit, or even metastasis to the liver or elsewhere. FAP can also develop 'silently' in some individuals, giving few or no signs until it has developed into advanced colorectal cancer.

Because familial polyposis develops very gradually over years, and can also manifest in an 'attenuated' form even more gradually, polyps resulting from FAP can lead to cancer developing at any point from adolescence to old age.

Depending on the nature of the defect in the APC gene, and whether it is the full or attenuated form, familial polyposis may manifest as polyps in colon or in the duodenal tract, or in any combination of these. Therefore, an absence of polyps in, for example, the rectum, may not of itself be sufficient to confirm absence of polyps. It may be necessary to consider and visually examine other possible parts of the intestinal tract. Colonoscopy is preferred over sigmoidoscopy for this, as it provides better observation of the common right-side location of polyps.

The genetic determinant in familial polyposis may also predispose carriers to other malignancies, e.g., of the duodenum and stomach (particularly ampullary adenocarcinoma). Other signs that may point to FAP are pigmented lesions of the retina ("CHRPE—congenital hypertrophy of the retinal pigment epithelium"), jaw cysts, sebaceous cysts, and osteomata (benign bone tumors). The combination of polyposis, osteomas, fibromas and sebaceous cysts is termed "Gardner's syndrome" (with or without abnormal scarring).

Attenuated familial adenomatous polyposis is a form of familial adenomatous polyposis, a cancer syndrome. It is a pre-malignant disease that can develop into colorectal cancer. A patient will have fewer than a hundred polyps located typically in right side of the colon. Cancer might develop as early as the age of five, though typically presents later than classical FAP.

EIN lesions have been discovered by a combination of molecular, histologic, and clinical outcome studies beginning in the 1990s which provide a multifaceted characterization of this disease. They are a subset of a larger mixed group of lesions previously called "endometrial hyperplasia". The EIN diagnostic schema is intended to replace the previous "endometrial hyperplasia" classification as defined by the World Health Organization in 1994, which have been separated into benign (benign endometrial hyperplasia) and premalignant (EIN) classes in accordance with their behavior and clinical management.

EIN should not be confused with an unrelated entity, serous intraepithelial carcinoma ("serous EIC"), which is an early stage of a different tumor type known as papillary serous adenocarcinoma that also occurs in the same location within the uterus.

Sebaceous adenomas, in isolation, are not significant; however, they may be associated with Muir-Torre syndrome, a genetic condition that predisposes individuals to cancer. It is also linked to hereditary nonpolyposis colorectal cancer (Lynch Syndrome).

It is not the same as "adenoma sebaceum" by F. Balzer and P.E. Ménétrier (1885). The term "adenoma sebaceum" is a misnomer for "facial angiofibromas" associated with tuberous sclerosis complex.

A sebaceous adenoma, a type of adenoma, a cutaneous condition characterized by a slow-growing tumor usually presenting as a pink, flesh-coloured, or yellow papule or nodule.