Lactology Foundation

ABDOMINAL SWELLINGS

These may be acute or chronic, general or local, and caused by abdominal accumulations that are gaseous, liquid or solid. They may arise in the abdominal cavity itself or in the abdominal wall.

SWELLINGS IN THE ABDOMINAL WALL
Swellings located in the abdominal wall itself can be recognized by their superficial position, by their adherence to the skin, subcutaneous fascia or muscles, or by their failure to follow the movements of the viscera immediately underlying the abdominal wall. It may be impossible to differentiate, for obvious reasons, an intra-abdominal mass that has become attached to the abdominal parietes, either as an inflammatory or malignant process. A simple test that should be applied to all abdominal masses is to ask patients to raise either their legs or their shoulders from the couch. This procedure tightens the abdominal muscles; if the lump is intraperitoneal, it disappears, but if it is situated in the abdominal wall itself it persists.

A large subcutaneous lipoma in the epigastrium this moved freely on the anterior abdominal wall, even when the underlying muscles were tightly contracted, thus excluding the diagnosis of an epigastric hernia.

Inflammatory swelling of the abdominal wall most commonly complicates a laparotomy incision, and the diagnosis is obvious. A superficial cellulitis may complicate infection of a small abrasion or hair follicle infection. Inflammation of the abdominal wall may be secondary to an extension of an intraperitoneal abscess, particularly an appendix abscess in the right iliac fossa, or, on the left side, a paracolic abscess in relation to diverticular disease of the sigmoid colon or to perforation of a carcinoma of the large bowel. Inflammatory swelling of the umbilicus in newborn infants is rare, except in primitive communities where the cord is not divided with the niceties of modern aseptic practice. Suppuration at the umbilicus in adults is not uncommon if the navel is deep and narrow.
A tender hematoma in the lower abdomen may result from rupture of the rectus abdominis muscle, or tearing of the inferior epigastric artery, which may occur as a result of a violent cough.
Tumors of the abdominal wall are usually subcutaneous lipomas. These may be multiple and may be a feature of Dercum's disease (adiposa dolorosa).
Lipomas should be carefully differentiated from irreducible umbilical or epigastric hernias containing omentum.
A desmoid tumor may arise in the lower part of the abdominal wall, and malignant fibrosarcomas or melanomas may also occasionally be encountered.
A neoplastic deposit may sometimes be palpated at the umbilicus and represents a transcoelomic seeding, usually from a carcinoma of the stomach or large bowel.

GENERAL ABDOMINAL SWELLINGS
Every medical student knows the mnemonic of the five causes of gross generalized swelling of the abdomen: Fat, Fluid, Flatus, Faeces and Fetus.
In obesity, the abdomen may swell either as a consequence of the deposit of fat in the abdominal wall itself, or as a result of adipose tissue in the mesentery, the omentum and the extraperitoneal layer. In very obese persons, it is rarely possible to
diagnose the exact nature of an intra-abdominal mass by the usual clinical methods. Indeed, tumors of quite remarkable size – including the full-term fetus – may remain occult to even the most careful examiner.
Distension of the intestines with gas occurs in intestinal obstruction and is particularly marked in cases of volvulus of the sigmoid colon, chronic large-bowel obstruction and megacolon. It also occurs in adynamic ileus. The whole of the abdomen, or in special cases some part of it, is distended and gives on percussion a highly resonant or tympanitic note. The outlines of the gas-distended viscera are often visible; loops of dilated small bowel, one above the other, may produce a characteristic 'ladder pattern'. The increased size of the inflated intestine may produce displacement of the other viscera; the dome of the diaphragm is pushed up into the chest, shifting the apex beat of the heart upwards. The liver is similarly displaced. The distended stomach may occasionally be gross enough all but to fill the abdomen in very advanced cases of pyloric stenosis and in acute gastric dilatation.
The causes producing an accumulation of liquid in the peritoneal cavity can be listed as:

• Congestive cardiac failure
• Cirrhosis
• Nephrotic syndrome
• Carcinomatosis peritonei
• Tuberculous peritonitis
In severe cases of chronic constipation, abdominal distension may result from the accumulation of faeces in the large intestine, particularly where megacolon exists. The scybala may be felt, usually soft and plastic in the region of the ascending colon, and hard and nodular in the descending and sigmoid colon. Rectal examination often reveals an enormous accumulation of faeces. In some cases of tuberculous peritonitis, semi-solid inflammatory masses may bring about a general swelling of the abdomen. General swelling of the abdomen may occur in malignant disease involving the peritoneum due to the growth of numerous secondary nodules in addition to a concomitant ascites. Pseudomyxoma peritonei may follow rupture of a pseudomucinous cystadenoma of the ovary or of a mucocoele of the appendix. The entire abdominal cavity becomes distended with gelatinous material.

LOCAL INTRA-ABDOMINAL SWELLINGS
These may be due to some general cause, or to a mass
arising in a specific viscus.
Swellings due to general causes
Causes that ordinarily produce general swelling of the abdomen may sometimes give rise to only a local swelling. Thus, with encysted ascites left after an acute diffuse peritonitis or accompanying tuberculous peritonitis, an accumulation of fluid bounded by adhesions between the adjacent viscera may be found
in any part of the peritoneal cavity, most often in the flanks or pelvis. A reliable history may be a clue to the nature of such a mass, although its cause may not be revealed until a laparotomy has been performed.
Abdominal swellings may occur in tuberculous peritonitis resulting from the rolled-up, matted and infiltrated omentum, doughy masses of adherent intestine, or enlarged tuberculous mesenteric lymph nodes. The amount of ascites in such cases varies considerably from a gross degree to almost complete absence (the obliterative form). Discovery of a tuberculous focus elsewhere in the body is support for the diagnosis.
Hydatid cysts may occur in any part of the abdominal cavity. They are usually single. The liver – particularly the right lobe – is the most common situation, and more rarely the spleen, omentum, mesentery or peritoneum. The cyst grows slowly and is spherical
except in so far as it is molded by the pressure of adjacent structures. It contains a clear fluid in which hooklets, scolices and secondary or daughter cysts detached from the walls of the parent cyst may be found.

Unless large enough to cause mechanical pressure, the single hydatid cyst gives rise to little pain, or indeed to any complaint of any kind. It may produce a smooth, rounded, tense bulging of the overlying abdominal wall. It is dull on percussion, and it may yield a 'hydatid thrill', as may any other cyst; this thrill is the vibratory sensation experienced by the rest of the hand when, with the whole hand laid flat over the tumor, a central finger is percussed. Occasionally, there may be pain and fever due to inflammation within these cysts, and rupture into the peritoneal cavity may cause a severe anaphylactic reaction. Rupture of a hydatid cyst of the liver into a bile duct may cause jaundice due to biliary obstruction by daughter cysts.
Hydatid disease is rare except in countries where the inhabitants live in close association with dogs that are the hosts of Taenia echinococcus (Australasia, South America, Greece, Cyprus and, in the British Isles, North Wales). About one-quarter of patients demonstrate eosinophilia. A complement fixation test gives a high
degree of accuracy. X-rays of the abdomen may reveal calcification of the cyst wall in long-standing cases.

Any part of the abdomen may swell from the formation of an abscess. A subphrenic abscess following a general peritonitis is occasionally large enough to produce an upper abdominal swelling.
The patient is usually seriously ill with a swinging fever, rapid pulse, leucocytosis and all the general manifestations of toxaemia. However, in this antibiotic era, an increasing number of examples are being seen of a more insidious and chronic progression of the disease, with the onset delayed weeks or even many months after the initial peritoneal infection. X-ray examination, together with screening of the diaphragm, is extremely useful, and at least 90 percent of patients with subphrenic infection have some abnormality on this investigation.
On the affected side, the diaphragm is raised and its sharp definition is lost. Its mobility on screening is diminished or absent. There is frequently a pleural effusion, collapse of the lung base or evidence of pneumonitis. About 25 percent of patients have gas
below the diaphragm, frequently associated with a fluid level. This gas is usually derived from a perforated abdominal viscus, but it is occasionally formed by gas-producing organisms. On the left side, gas under the diaphragm may be confused with the gastric bubble. An important differential feature is that the gas shadow of the stomach rarely reaches the lateral abdominal wall; however, if there is doubt, a mouthful of barium is given in order to demarcate the stomach.
Ultrasonography and computed tomography usually clinch the diagnosis.

Pus may localize in either the right or left paracolic gutter or iliac fossa. On the right side, this usually follows a ruptured appendix, or occasionally a perforated duodenal ulcer. On the left, a perforation of an inflamed diverticulum or carcinoma of the sigmoid colon is the usual cause. A large pelvic abscess frequently extends above the pubis or into one or the other iliac fossa from the pelvis and can be palpated abdominally as well as on pelvic or rectal examination.
About 75 percent result from gangrenous appendicitis, and the remainder follow gynecological infections, pelvic surgery or any general peritonitis.

Regional diagnosis of local abdominal swellings
For clinical purposes, the abdomen may be subdivided into nine regions by two vertical lines drawn upwards from the mid-inguinal point midway between the anterior superior iliac spine and the symphysis pubis, and by two horizontal lines, the upper one passing through the lowest points of the tenth ribs (the subcostal line), the other drawn at the highest points of the iliac crests – the supra-cristal plane (Fig).
The three median areas thus mapped out are named, from above downwards, the epigastric, umbilical and hypogastric (or suprapubic) regions; the six lateral areas are, from above downwards, the right and left hypochondriac, lumbar and iliac regions. The abdominal swellings that may be felt in and about these nine regions, excluding the tumors located in the abdominal wall itself that have already been described, are as follows.

Right hypochondriac region
Most tumors in this area are connected with the liver or gallbladder.
An easily made mistake is to regard the firm and rounded swelling produced by the upper segment of the right rectus abdominis muscle, especially in a well-developed subject, as a tumor of the liver or gallbladder. In such cases, the characteristic dull note of the liver on percussion over the lower right chest ceases at the costal margin.
Tumors in connection with the hepatic flexure of the colon, scybalous collections in the hepatic flexure region, or the head of an intussusception may present as masses in this area.

Epigastric region
Enlargement of the liver may be felt in this area, and indeed it is common to feel the normal liver in this region, especially in infants and in adults with an acute costal angle. The dilated stomach produced by pyloric stenosis in either children or adults may present as a visible swelling demonstrating waves of peristalsis
traveling from left to right. A succession splash is usually elicited. Tumors of the stomach, apart from malignant growth, are rare. A hundred years ago, a hair ball or trichobezoar was frequently encountered as an epigastric mass in hysterical girls who chewed
and swallowed their hair, which then formed an exact mold of the stomach. Hair balls are only rarely encountered these days, and modern textbooks hardly mention them; however, as fashions and hair styles change, they may reappear on the clinical scene. Other foreign bodies are sometimes ingested by those with learning difficulties and form a palpable mass. In congenital pyloric stenosis, a tumor the size of a small marble is palpable at the right border of the right rectus.
The transverse colon usually passes across the upper
part of the umbilical area, and may be palpated when
it is the site of a carcinoma, when it is impacted with faeces or when it is distended by a large-bowel
obstruction placed distal to it.
Swellings in connection with the omentum may be due to tuberculous peritonitis or, more commonly, due to infiltration with secondary malignant deposits.
Swellings arising from the pancreas push forward from the depths of the abdominal cavity towards the epigastric and the upper part of the umbilical areas, and present themselves as vaguely palpable deeply seated masses. They have the stomach, or the
stomach and colon, in front of them and are fixed to the posterior abdominal wall, thus moving only a little on respiration. They may transmit a non-expansile pulsation from the subjacent aorta. Unless extremely large, such swellings are resonant on percussion, due to the overlying air-filled gut. A pancreatic swelling may be carcinomatous, in which case wasting, anemia and jaundice are likely to be observed. There may be clay colored stools and dark urine, and it is important to note that the onset of jaundice is frequently preceded by deeply placed abdominal pain, or pain in the back.
Glycosuria of recent origin in an elderly patient also raises suspicion of a pancreatic carcinoma. In about half of the patients with jaundice due to carcinomatous obstruction, the gallbladder is palpably distended (Courvoisier's law). Occasionally, the mass may result from chronic pancreatitis; the swollen pancreas of acute pancreatitis has only exceptionally been palpated before laparotomy.

Pancreatic cysts are the pancreatic swellings that are most commonly palpable. Only 20 percent are true cysts; these are either single or multiple retention cysts that usually result from chronic pancreatitis, neoplastic cysts (cystadenoma and cystadeno-carcinoma) and the rare congenital polycystic disease of the pancreas and hydatid cyst of the pancreas. Far more often, the cysts are not in the pancreas itself but comprise a collection
of fluid sealed off in the lesser sac due to closure of the foramen of Winslow (pseudocyst of the pancreas).
This may occur after trauma to the pancreas, following acute pancreatitis or, much less commonly, resulting from perforation of a posterior gastric ulcer. They may reach an enormous size and fill the entire upper part of the abdomen.
Retroperitoneal cysts are rare. The majority arise from remnants of the mesonephric (Wolffian) duct and occur in adult women. Others are teratomatous, lymphangiomatous or dermoid.
Retroperitoneal tumors (apart from those arising in the pancreas, suprarenal gland or kidney) originate in the mesenchymal tissues, the sympathetic chain and the para-aortic lymph nodes.

Swellings in connection with the duodenum are exceedingly rare. They may result from an inflammatory mass developing around a penetrating duodenal ulcer, or be due to a duodenal malignant tumor, but the latter is a pathological curiosity. Those in connection with the kidneys and suprarenal glands are found in the epigastrium only if very large. Their diagnosis is considered below.
Enlargement of the spleen may bring its anterior edge into the epigastric area; a splenic swelling always lies in contact with the anterior wall of the abdomen.
Lymph nodes, which are numerous in the para-aortic retroperitoneal tissues and in the mesentery, may become palpable in reticuloses, tuberculous peritonitis, or malignant disease as nodulated chains or masses.

Left hypochondriac region
An abnormal lobe or a tumor in the left lobe of the liver may appear as a superficial tumor in this area. Much of the stomach normally lies in the left hypochondrium; the diagnosis of gastric swelling has been considered above, and a gastric tumor is commonly felt in this region. On physical signs alone, it must be differentiated from a swelling of the adjacent spleen. A barium-meal X-ray examination, ultrasound or computed tomography (CT) scan help considerably in differentiating between a gastric and
a splenic swelling.
The diagnosis of a tumor of the splenic flexure of the colon, whether scybalous or malignant, is arrived at in the same way as in the case of a tumor of the hepatic flexure or transverse colon. The distinguishing features are that the spleen comes down from under the left costal margin in direct contact with the anterior abdominal wall (and is therefore dull on percussion), descends on inspiration and has a smooth surface, and a notch may be palpable on its inner margin. A splenic swelling may be identified on a plain X-ray of the abdomen and differentiated from a renal mass by means of pyelography. A barium meal examination may show displacement and indentation of the adjacent stomach.
Ultrasound or CT scan will clinch the diagnosis.
Tumors of the pancreas may project into the left hypochondrium, as may retroperitoneal tumors and cysts. Tumors of the left kidney and suprarenal gland have the stomach and colon in front of them and therefore, unless extremely large, are resonant on percussion.
Since they arise in the loin, these masses can usually be balloted by bimanual palpation.

Right lumbar region
Occasionally, a congenital projection of the liver, known as Riedel's lobe, may appear as a superficial tumor continuous with the liver above it in this zone.
It may be mistaken for a dilated gallbladder. The ascending colon may be palpable due to contained faecal masses, owing to thickening as a result of long-standing colitis, Crohn's disease or hyperplastic tuberculosis, or due to malignant disease.
The ascending colon can be felt in acute or chronic ileocaecal and ileocolic intussusception as a sausage shaped tumor, at first situated in the right flank, then moving across the abdomen above the umbilicus and finally down the left flank into the pelvis. The
vast majority of these cases occur in infants or young children, usually aged between 3 and 12 months.
Boys are affected twice as often as girls. The history is of paroxysms of abdominal colic typified by screaming and pallor. There is vomiting and usually the passage of blood and mucus per rectum, giving the characteristic 'redcurrant jelly stool'. A rectal examination almost always reveals this typical feature, and rarely the tip of the intussusception can be felt. In infants, there
is usually no obvious cause, but the mesenteric lymph nodes in these cases are invariably enlarged. In adults, a polyp, carcinoma or an inverted Meckel's diverticulum may form the apex of the intussusception.
Tumours in connection with the right kidney and suprarenal gland usually appear deep down in this region, having the ascending colon and small intestine in front of them. They can be lifted forward en masse from behind by a hand placed at the back of the loin and thus palpated bimanually. The lower pole of the right kidney can be felt in some normal persons on deep abdominal palpation, especially in thin females. When abnormally low and mobile, the whole of the otherwise normal kidney may be palpable. Its shape and consistency are characteristic. Renal swellings move on respiration and, unless very large, are resonant on percussion due to the anteriorly related gut. However, Riedel's lobe of the liver, an enlarged gallbladder, masses in the ascending colon and secondary deposits in the omentum have all been mistaken for it, although they are more superficially placed and lie in contact with the anterior abdominal wall. Other wandering
masses, for example those arising from the ovary, Fallopian tube and mesentery, as well as hydatid cysts, are all liable to the same error of identification. Imaging by means of ultrasound or CT scanning is invaluable in assisting with the differential diagnosis.

Umbilical region
The grossly dilated stomach resulting from long-standing pyloric obstruction may occupy the umbilical region; indeed, it may descend below it down into the pelvis.
Tumors in connection with the transverse colon have been considered in 'Epigastric region' and 'Right lumbar region', above.
Tumors in connection with the omentum are common in this region; those arising from the small intestine are much rarer, although the thickened small bowel in Crohn's disease may form a palpable mass.
Swellings arising from the kidneys, suprarenal glands, pancreas, retroperitoneal tissues, para-aortic nodes and mesentery may all present themselves in the deeper parts of the umbilical region, usually as more or less fixed masses arising from or connected with the posterior wall of the abdomen.
The aorta bifurcates 1 cm below and to the left of the umbilicus in the supracristal plane. Above (at the level of the fourth lumbar
vertebrae). In thin patients, pulsation of the normal aorta can often be felt and indeed seen in this region, and may lead to the incorrect diagnosis of an abdominal aneurysm. Careful examination, however, will show that this pulsation is no more than a throbbing, an up-and-down movement, and is not laterally expansive.
Aneurysm of the abdominal aorta forms an expansile mass situated above the umbilicus itself, and it may be accompanied by pain in the back from erosion of the bodies of the lumbar vertebrae. Often, X-rays of the abdomen in such cases will reveal calcification in the aneurysmal wall. Ultrasound and CT enable accurate delineation of the size and extent of the aneurysm.
These methods are also valuable in the visualization of the other retroperitoneal masses enumerated above.

Left lumbar region
An enlarged spleen (see 'Left hypochondriac region', above) may protrude into this area. It forms a firm mass that is in contact with the abdominal wall, and its dullness to percussion continues with its thoracic dullness, which extends back up into the axilla along the line of the ninth or tenth ribs. Tumors in connection with the right kidney, the right suprarenal gland and the descending colon give rise to features similar to those considered in 'Left hypochondriac region', above.

Right iliac fossa
An inflammatory mass in this region is most commonly associated with an appendix abscess.
Less commonly, there may be a paracaecal abscess in relation to a perforated carcinoma of the caecum, or a solitary caecal benign ulcer. A pyosalpinx may result from salpingitis and, rarely, inflammatory swellings may arise in connection with suppurating iliac lymph nodes or a psoas abscess.
An important differential diagnosis is between an appendix mass and a carcinoma of the caecum. In the former, there is usually a preceding episode of an acute abdominal pain, typical of appendicitis, with fever and leucocytosis. The inflammatory mass subsides progressively over 2–3 weeks, and the occult blood test
in the stools is negative. A carcinoma of the caecum may be suspected if there is a preceding history of bowel disturbance in a middle-aged or elderly patient, if the mass fails to resolve rapidly and if the occult blood test in the stools is repeatedly positive. If there is any clinical doubt, a barium enema X-ray examination should be carried out and, if necessary, resort made to laparotomy.
It is not at all rare for a soft 'squelchy' caecum to be palpable in a perfectly normal thin female subject.
Occasionally, a grossly distended gallbladder may project down as far as the right iliac fossa, and a low-lying kidney may form a palpable mass in this region.
Rarely, an ectopic kidney may be felt in one or the other iliac fossa and, these days, a transplanted kidney may be palpated at this site. An ovarian tumor or cyst or a pedunculated fibroid of the uterus may project into this area.

Hypogastric region
The most common mass to be felt in this region, after the pregnant uterus, is the distended bladder. This may reach as high as, or slightly above, the umbilicus. Not uncommonly, this midline structure tilts over to one or the other side. A distended bladder has been tapped as ascites, operated upon as an ovarian cyst or a fibroid, or mistaken for the pregnant uterus. No diagnostic opinion should be advanced, and no operative procedure undertaken respecting a tumor in this situation, until the bladder has been
emptied, either by voluntary micturition or by the passage of a catheter.
Abdominal swellings arising from the uterus, ovaries, Fallopian tubes and uterine ligaments may all rise up out of the pelvis and present themselves as swellings in this region; as they grow larger, they may be spread into any part of the abdomen. While they remain comparatively small and are manifestly connected with some intrapelvic organ, their origin is not difficult to determine.
However, when they have extended into the abdomen or have acquired a long pedicle, or have become fixed by adhesions to some distant part of the abdominal wall or to some other viscus, these pelvic tumors may give rise to signs and symptoms that bear no relation to pelvic disease. In such cases, they may only
be correctly diagnosed at laparotomy. The discerning clinician will always remember the possibility of pregnancy in every female patient between menarche and menopause. The diagnosis is confirmed by the urinary pregnancy test (positive beta human
chorionic gonadotrophin (hCG)) and, if necessary, by pelvic ultrasonography.
Tumors of ileal Crohn's disease arising in the small intestine may be felt in the hypogastric area.
The urachus is a fibrous cord running in the middle line in front of the peritoneum from the fundus of the bladder to the umbilicus. Occasionally, it becomes the seat of cyst formation, more often in women than in men. The urachal cyst is a rounded tumor lying
between the umbilicus and the pubic symphysis, which occasionally becomes infected.

Left iliac fossa
The pelvic colon can often be felt in normal subjects as a tube-like cord, either when empty and in spasm, or else when distended with faecal masses. The region is a common site for carcinoma of the colon, and there are usually symptoms of chronic intestinal
obstruction, or bowel disturbance with the passage of blood and mucus in the stools. It is clinically impossible to differentiate between such a mass and that associated with diverticular disease of the sigmoid colon. Similarly, a paracolic abscess in this region may equally well be associated with suppuration of an inflamed colonic diverticulum or a perforating carcinoma. Rarely, such an abscess may be due to perforation of the tip of a long appendix passing over the left iliac fossa, or as an extreme rarity due to local perforation of a left-sided appendix in transposition of
the viscera. The diagnosis of this would be suggested by finding the cardiac apex beat to lie on the right side.