The diagnosis is largely a clinical one, generally done by physical examination of the groin. However, in obese patients, imaging in the form of ultrasonography, CT or MRI may aid in the diagnosis. An abdominal x-ray showing small bowel obstruction in a female patient with a painful groin lump needs no further investigation.

Several other conditions have a similar presentation and must be considered when forming the diagnosis: inguinal hernia, an enlarged inguinal lymph node, aneurysm of the femoral artery, saphena varix, and an abscess of the psoas.

Simple excision is the treatment of choice, although given the large size, bleeding into the space can be a potential complication. Isolated recurrences may be seen, but there is no malignant potential.

Given the anatomic site, a spindle cell lipoma, nuchal-type fibroma and fibromatosis colli are all included in the differential diagnosis.

Complete surgical excision is the treatment of choice, associated with an excellent long term clinical outcome.

This disease is often discovered during surgery for other conditions, e.g., hernia repair, following which an experienced pathologist can confirm the diagnosis. Advanced stages may present as tumors palpable on the abdomen or distention of the belly ("jelly belly" is sometimes used as a slang term for the condition). Due to the rarity of this disease, it is important to obtain an accurate diagnosis so that appropriate treatment may be obtained from a surgical oncologist who specializes in appendix cancer. Diagnostic tests may include CT scans, examination of tissue samples obtained through laparoscopy, and the evaluation of tumor markers. In most cases a colonoscopy is unsuitable as a diagnostic tool because in most cases appendix cancer invades the abdominal cavity but not the colon (however, spread inside the colon is occasionally reported). PET scans may be used to evaluate high-grade mucinous adenocarcinoma, but this test is not reliable for detecting low-grade tumors because those do not take up the dye which shows up on scans. New MRI procedures are being developed for disease monitoring, but standard MRIs are not typically used as a diagnostic tool. Diagnosis is confirmed through pathology.

Femoral hernias, like most other hernias, usually need operative intervention. This should ideally be done as an elective (non-emergency) procedure. However, because of the high incidence of complications, femoral hernias often need emergency surgery.

Usually, treatment of a lipoma is not necessary, unless the tumor becomes painful or restricts movement. They are usually removed for cosmetic reasons, if they grow very large, or for histopathology to check that they are not a more dangerous type of tumor such as a liposarcoma. This last point can be important as the characteristics of a "bump" are not known until after it is removed and medically examined.

Lipomas are normally removed by simple excision. The removal can often be done under local anaesthetic, and takes less than 30 minutes. This cures the great majority of cases, with about 1–2% of lipomas recurring after excision. Liposuction is another option if the lipoma is soft and has a small connective tissue component. Liposuction typically results in less scarring; however, with large lipomas it may fail to remove the entire tumor, which can lead to regrowth.

New methods under development are supposed to remove the lipomas without scarring. One is removal by injecting compounds that trigger lipolysis, such as steroids or phosphatidylcholine.

2002 the CT scan was assessed for it reliability for imaging inflammatory aortic aneurysms and to quantitatively evaluate its features. The finding were that CT scan was a reliable means to diagnose IAA.

2008 a study was done to test the effectiveness of MRI and FDG-PET tests to detect, diagnose, and measure inflammatory aortic arch syndrome. The results from the study were that MRI and FDG-PET were unreliable techniques due to giant cell arteritis.

2015 following endovascular repair of an aortic aneurysm the type of the endograft’s material used for repair seems to play a role in the inflammatory response associated with IAA.

Splenic rupture is usually evaluated by FAST ultrasound of the abdomen. Generally this is not specific to splenic injury; however, it is useful to determine the presence of free floating blood in the peritoneum. A diagnostic peritoneal lavage, while not ideal, may be used to evaluate the presence of internal bleeding a person who is hemodynamically unstable. The FAST exam typically serves to evaluate the need to perform a CT. Computed tomography with IV contrast is the preferred imaging study as it can provide high quality images of the full peritoneal cavity.

American Association for the Surgery of Trauma Organ Injury Scaling: Splenic Injury Grading

It is important to separate hiberoma from adult rhabdomyoma, a granular cell tumor and a true liposarcoma.

The benefits of the use of an external device to maintain reduction of the hernia without repairing the underlying defect (such as hernia trusses, trunks, belts, etc.) are unclear.

Corticosteroids and other immunosuppressive drugs have been found to decrease symptoms and the degree of peri-aortic inflammation and fibrosis.

Traditional "open" repair of incisional hernias can be quite difficult and complicated. The weakened tissue of the abdominal wall is re-incised and a repair is reinforced using a prosthetic mesh. Complications, particularly infection of the incision, frequently occur because of the large size of the incision required to perform this surgery. A mesh infection after this type of hernia repair most frequently requires a complete removal of the mesh and ultimately results in surgical failure. In addition, large incisions required for open repair are commonly associated with significant postoperative pain. Reported recurrence rates after open repair are up to 20% and influenced by mesh size and fixation type.

Laparoscopic incisional hernia repair is a new method of surgery for this condition. The operation is performed using surgical microscopes and specialized instruments. The surgical mesh is placed into the abdomen underneath the abdominal muscles through small incisions to the side of the hernia. In this manner, the weakened tissue of the original hernia is never re-incised to perform the repair, and one can minimize the potential for wound complications such as infections. In addition, performance of the operation through smaller incisions can make the operation less painful and speed recovery. Laparoscopic repair has been demonstrated to be safe and a more resilient repair than open incisional hernia repair.

Lipomas are rarely life-threatening and the common subcutaneous lipomas are not a serious condition. Lipomas growing in internal organs can be more dangerous; for example lipomas in the gastrointestinal tract can cause bleeding, ulceration and painful obstructions (so-called "malignant by location", despite being a benign growth histologically). Malignant transformation of lipomas into liposarcomas is very rare and most liposarcomas are not produced from pre-existing benign lesions. A few cases of malignant transformation have been described for bone and kidney lipomas, but it is possible these few reported cases were well-differentiated liposarcomas in which the subtle malignant characteristics were missed when the tumour was first examined. Deep lipomas have a greater tendency to recur than superficial lipomas, because complete surgical removal of deep lipomas is not always possible.

The presence of multiple lipomas is known as lipomatosis and is more commonly encountered in men. Some superficial lipomas can extend into deep fascia and may complicate excision. Liposarcoma is found in 1% of lipomas and are more likely in lesions of the lower extremities, shoulders and retroperitoneal areas. Other risk factors for liposarcoma include large size (>5 cm), associated with calcification, rapid growth and/or invasion into nearby structures or through fascia into muscle tissue.

In some communities mothers routinely push the small bulge back in and tape a coin over the palpable hernia hole until closure occurs. This practice is not medically recommended as there is a small risk of trapping a loop of bowel under part of the coin resulting in a small area of ischemic bowel. This "fix" does not help and germs may accumulate under the tape, causing infection. The use of bandages or other articles to continuously reduce the hernia is not evidence-based.

An umbilical hernia can be fixed in two different ways. The surgeon can opt to stitch the walls of the abdominal or he/she can place mesh over the opening and stitch it to the abdominal walls. The latter is of a stronger hold and is commonly used for larger defects in the abdominal wall. Most surgeons will not repair the hernia until 5–6 years after the baby is born. Most umbilical hernias in infants and children close spontaneously and rarely have complications of gastrointestinal-content incarcerations.

How far the projection of the swelling extends from the surface of the abdomen (the belly) varies from child to child. In some, it may be just a small protrusion; in others it may be a large rounded swelling that bulges out when the baby cries. It may hardly be visible when the child is quiet and or sleeping.

Normally, the abdominal muscles converge and fuse at the umbilicus during the formation stage, however, in some cases, there remains a gap where the muscles do not close and through this gap the inner intestines come up and bulge under the skin, giving rise to an umbilical hernia. The bulge and its contents can easily be pushed back and reduced into the abdominal cavity.

In contrast to an inguinal hernia, the complication incidence is very low, and in addition, the gap in the muscles usually closes with time and the hernia disappears on its own. The treatment of this condition is essentially conservative: observation allowing the child to grow up and see if it disappears. Operation and closure of the defect is required only if the hernia persists after the age of 3 years or if the child has an episode of complication during the period of observation like irreducibility, intestinal obstruction, abdominal distension with vomiting, or red shiny painful skin over the swelling. Surgery is always done under anesthesia. The defect in the muscles is defined and the edges of the muscles are brought together with sutures to close the defect. In general, the child needs to stay in the hospital for 2 days and the healing is complete within 8 days.

At times, there may be a fleshy red swelling seen in the hollow of the umbilicus that persists after the cord has fallen off. It may bleed on touch, or may stain the clothes that come in contact with it. This needs to be shown to a pediatric surgeon. This is most likely to be an umbilical polyp and the therapy is to tie it at the base with a stitch so that it falls off and there is no bleeding. Alternatively, it may be an umbilical granuloma that responds well to local application of dry salt or silver nitrate but may take a few weeks to heal and dry.

Treatment is mainly surgical; radiotherapy or chemotherapy is usually an indication of relapse. Head and neck desmoid fibromatosis is a serious condition due to local aggression, specific anatomical patterns and the high rate of relapse. For children surgery is particularly difficult, given the potential for growth disorders.

Treatment includes prompt radical excision with a wide margin and/or radiation. Despite their local infiltrative and aggressive behavior, mortality is minimal to nonexistent for peripheral tumours. In intra-abdominal fibromatosis associated with Familial adenomatous polyposis (FAP), surgery is avoided if possible due to high rates of recurrence within the abdomen carrying significant morbidity and mortality. Conversely, for intra-abdominal fibromatosis without evidence of FAP extensive surgery may still be required for local symptoms, but the risk of recurrence is low.

Many people are managed through day surgery centers, and are able to return to work within a week or two, while intense activities are prohibited for a longer period. People who have their hernias repaired with mesh often recover within a month, though pain can last longer. Surgical complications include pain that lasts more than three months, surgical site infections, nerve and blood vessel injuries, injury to nearby organs, and hernia recurrence. Pain that lasts more than three months occurs in about 10% of people following hernia repair.

A technetium-99m (99mTc) pertechnetate scan, also called Meckel scan, is the investigation of choice to diagnose Meckel's diverticula in children. This scan detects gastric mucosa; since approximately 50% of symptomatic Meckel's diverticula have ectopic gastric or pancreatic cells contained within them, this is displayed as a spot on the scan distant from the stomach itself. In children, this scan is highly accurate and noninvasive, with 95% specificity and 85% sensitivity; however, in adults the test is only 9% specific and 62% sensitive.

Patients with these misplaced gastric cells may experience peptic ulcers as a consequence. Therefore, other tests such as colonoscopy and screenings for bleeding disorders should be performed, and angiography can assist in determining the location and severity of bleeding. Colonoscopy might be helpful to rule out other sources of bleeding but it is not used as an identification tool. Angiography might identify brisk bleeding in patients with Meckel's diverticulum.

Ultrasonography could demonstrate omphaloenteric duct remnants or cysts. Computed tomography (CT scan) might be a useful tool to demonstrate a blind ended and inflamed structure in the mid-abdominal cavity, which is not an appendix.

In asymptomatic patients, Meckel's diverticulum is often diagnosed as an incidental finding during laparoscopy or laparotomy.

Ovarian torsion is difficult to diagnose accurately, and operation is often performed before certain diagnosis is made. A study at an obstetrics and gynaecology department found that preoperative diagnosis of ovarian torsion was confirmed in only 46% of people.

Treatment is variable, both due to its rarity and to its frequently slow-growing nature. Treatment ranges from watchful waiting to debulking and hyperthermic intraperitoneal chemotherapy (HIPEC, also called intraperitoneal hyperthermic chemotherapy, IPHC) with cytoreductive surgery.

Desmoid tumors may be classified as extra-abdominal, abdominal wall, or intra-abdominal (the last is more common in patients with FAP). It is thought that the lesions may develop in relation to estrogen levels or trauma/operations.

A 3' APC mutation is the most significant risk factor for intra-abdominal desmoid development amongst FAP patients. FAP patients presenting with an abdominal wall desmoid pre-operatively are at an increased risk of developing an intra-abdominal desmoid post-operatively.

Desmoid tumours of the breast are rare. Although benign, they can mimic breast cancer

on physical examination, mammography and breast ultrasound and can also be locally invasive. Even

though they occur sporadically, they can also be seen as a part of Gardner's syndrome. A high index of suspicion and a thorough triple examination protocol is necessary to detect rare lesions like a desmoid tumour which can masquerade as breast carcinoma. Desmoid tumour of the breast may present a difficulty in the diagnosis especially where imaging studies are not conclusive and suggest a more ominous diagnosis.

Investigations by the physician include imaging (ultrasound, CAT scan, MRI) and, if possible, obtaining a tissue diagnosis by biopsy, hysteroscopy, or D&C.

Ultimately the diagnosis is established by the histologic examination of the specimen. Typically malignant lesions have >10 mitosis per high power field. In contrast a uterine leiomyoma as a benign lesion would have < 5 mitosis per high power field.

The diagnosis is based on examination under a microscope, by a pathologist. Radiologic findings may be suggestive, as these tumors are well-circumscribed and devoid of calcifications.

Treatment is surgical, potentially with a laparoscopic resection. In patients with bleeding, strangulation of bowel, bowel perforation or bowel obstruction, treatment involves surgical resection of both the Meckel's diverticulum itself along with the adjacent bowel segment, and this procedure is called a "small bowel resection". In patients without any of the aforementioned complications, treatment involves surgical resection of the Meckel's diverticulum only, and this procedure is called a simple diverticulectomy.

With regards to asymptomatic Meckel's diverticulum, some recommend that a search for Meckel's diverticulum should be conducted in every case of appendectomy/laparotomy done for acute abdomen, and if found, Meckel's diverticulectomy or resection should be performed to avoid secondary complications arising from it.