Only some of the diseases of the abdominal wall are peculiar to this region or present special difficulties in diagnosis. There is a small group of congenital malformations of the umbilicus, of which hernia (see Chap. XLL) is the most common. A bright-red fleshy growth at the umbilicus, presenting a smooth surface and a short central canal, discharging mucus, is an adenoma or polypus; but if it is lobular in outline, discharges pus, and has no central canal, it is a granuloma. Should the umbilicus be excoriated and a watery fluid escape from it, this is probably urine flowing through a urachal fistula. The detection of urea will determine that the fluid is urine. The urethra should then be examined for stricture. Congenital fistulas (ileocecal, or gastric fistulas) are sometimes met with.
When there is a direct communication between the skin and the intestine so that the mucous membrane is continuous with the skin, the condition is spoken of as an artificial anus. The surgeon will know by the reaction and appearance of the discharge what part of the alimentary canal is opened. He should look carefully at the 'spur' of the intestine which projects into and sometimes blocks up the lumen of the tube to ascertain whether there is a coil of intestine protruding behind it; this can be felt, or on manipulation a gurgle may be detected. A fecal fistula may be met with in any part of the abdominal wall.
Biliary, pancreatic, and gastric fistulas are recognized by the chemical and digestive characters of the fluid escaping from them. A sinus may be met with as the result of an abscess in the abdominal wall or in the abdominal cavity; the history of the case, the presence of other signs of disease such as curvature of the spine or tumour in the abdomen, and the recognition of specific organisms in the discharge will determine the diagnosis.
Tumours of the abdominal wall are to be distinguished from tumours of the abdominal cavity by their mobility with the belly-wall, and by the fact that they become more prominent when the abdominal muscles contract, as in coughing; abdominal tumours, if movable, move independently of the tissues over them. In some cases tumours beginning in the abdominal wall grow into the cavity and become adherent to the viscera, and intra-abdominal growths may extend into the belly-wall. The most common tumours are hernias, umbilical or ventral (Chap. XLI.), lipoma, fibroma, sarcoma, epithelioma, and abscess.
A haematoma in the sheath of the rectus muscle forms a tense and tender swelling of elongated form, dull on light percussion. It becomes more prominent when the patient coughs, and is by this fact distinguished, when on the right side, from an enlarged gall-bladder, or from an intra-abdominal swelling due to appendicitis.
An ill-defined, firm, slowly growing or stationary tumour of the deeper layers of the abdominal wall is a fibroma or desmoid tumour; this occurs most often in women who have borne children; it grows from and along the deep layer of the sheath of the rectus, and forms an elongated, irregular fibrous mass. This tumour may recur after apparently complete removal, and tends with the passage of time to become definitely sarcomatous in character.
An ovoid or globular mass, firm in consistence, attached to the broad muscles of the abdominal wall and steadily increasing in size, is a sarcoma. Sarcoma may arise in an irreducible omental umbilical hernia.
Epithelioma of the umbilicus occurs in two forms: (1) as a primary squamous epithelioma of the surface of the skin with enlargement of glands in axillae and groins; and (2) as a columnar epithelioma of the subcutaneous tissue, secondary to a similar growth in the stomach or intestine, and situated in the subcutaneous tissue. In some cases such a secondary growth is the first indication of the presence of the disease in the digestive tract.
Abscess in the abdominal wall may be superficial or deep; the former is easily diagnosed by the fluctuation and the signs of acute inflammation. Deep abscess may form in the sheath of the rectus muscle or underneath the muscular aponeuroses. If a tumour with the signs of inflammation (pain, tenderness, heat, and redness) forms in the belly-wall, and its outline corresponds to one of the divisions of the rectus muscle, it is an abscess in the sheath of this muscle. Fluctuation is very difficult to obtain in acute abscess, and the induration and surrounding oedema are marked; in chronic abscess, induration and oedema are absent and fluctuation is more distinct. These abscesses are to be distinguished from pointing intra-abdominal abscesses by the absence of an expansile impulse on coughing, and by the entire irreducibility of the swelling by pressure. Great care is required to distinguish the thrusting impulse of swellings in the abdominal wall from the increased tension and filling out of the tumour which characterize fluid swellings of the cavity extending into the walls. The subaponeurotic abscesses can only be distinguished from localized collections of pus in the peritoneal cavity by operation.
<Callout type="warning" title="Danger: Misdiagnosis">Failure to correctly diagnose an abdominal wall condition could lead to severe complications or even death.</Callout>
<Callout type="important" title="Key Point: Tumour Characteristics">Tumours of the abdominal wall become more prominent when the abdominal muscles contract, whereas intra-abdominal tumours move independently of the tissues over them.</Callout>
Key Takeaways
- Recognize congenital malformations and fistulas in the abdominal wall.
- Differentiate between superficial and deep abscesses based on signs of inflammation.
- Understand how to distinguish tumours of the abdominal wall from intra-abdominal ones.
Practical Tips
- Use chemical tests to identify fluid discharge from biliary, pancreatic, or gastric fistulas.
- Look for specific anatomical landmarks like the 'spur' in an artificial anus to determine the origin of the discharge.
- Be cautious when diagnosing abscesses as they can be easily confused with other conditions.
Warnings & Risks
- Misdiagnosis of abdominal wall diseases can lead to severe complications or death.
- Deep abscesses may not show signs of fluctuation and require careful examination.
Modern Application
While the diagnostic techniques described in this chapter are outdated, understanding historical methods provides a foundation for modern medical practices. The principles of recognizing anatomical landmarks and distinguishing between superficial and deep conditions remain relevant today.
Frequently Asked Questions
Q: What is an adenoma or polypus?
An adenoma or polypus is a bright-red fleshy growth at the umbilicus with a smooth surface, short central canal, and mucus discharge. It should be distinguished from a granuloma which discharges pus without a central canal.
Q: How do you diagnose an artificial anus?
An artificial anus is diagnosed by observing direct communication between the skin and intestine where mucous membrane is continuous with the skin, and identifying the part of the alimentary canal based on discharge characteristics.
Q: What distinguishes a fibroma from other abdominal wall tumours?
A fibroma or desmoid tumour occurs most often in women who have borne children. It grows slowly and is firm, attached to the deep layer of the sheath of the rectus muscle, and may recur after removal.
Q: How do you differentiate between superficial and deep abscesses?
Superficial abscesses are easily diagnosed by fluctuation and signs of acute inflammation. Deep abscesses lack fluctuation but have marked induration and oedema in the acute stage, with less distinct signs in chronic stages.