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Midline abdominal mass

Introduction
Cause
Examine
Diagnosis

Introduction

Introduction The mass at the midline of the abdomen is a clinical feature of the white line. The bilateral rectus abdominis sheaths are interwoven in the midline of the abdomen to form a belly white line. The abdominal visceral vaginal white line is called the hernia of white line.

Cause

Cause

(1) Causes of the disease

The white line is located between the xiphoid process and the pubic symphysis. It is the aponeurosis fibers of the 3 layers of the anterior and lateral ventricles (external oblique, intra-abdominal oblique, and transverse abdominis) between the left and right rectus abdominis. The sturdy strips formed by interlacing and interlacing are wide and narrow, and the white line on the umbilicus is 1.25 to 2.5 cm wide. The umbilicus is narrow and thick, and the width is mostly only 0.1 cm (Fig. 2, 3). The vast majority of white mites occur on the umbilicus, and rare occurrences under the umbilicus may have important implications.

The inner and outer surfaces of the abdominal white line have different structural features. On the outer surface, the intersecting peritoneal fibers are uniform in thickness and closely intertwined. Except for small blood vessels and small holes pierced by nerve branches, rare large pores are rare. The inner surface of the aponeurotic fiber bundle is uneven in thickness, often forming a thick bundle or a plate shape, and the direction is not regular. There are holes, dimples or fissures between the cross fibers interspersed with nerves and blood vessels, so that the inner layer of the white line is defective. This type of defect is the weak part of the abdominal white line. If the intra-abdominal pressure increases, the extraperitoneal fat and peritoneum enter the larger defect under the push of abdominal pressure, that is, white mites are formed. According to Rizk, all of the peritoneal fibers of the anterior ventral lateral wall muscles intersect obliquely to form a small "diamond gap" in the abdominal white line, which can be expanded into an ankle ring.

4cm below the umbilicus, the edge of the half-ring line is a weak point on the white line, and the white line under the umbilicus often occurs here.

It can be seen that the white line sputum is related to the decrease of the strength of the abdominal wall and the increase of the intra-abdominal pressure.

1. The wall strength is weakened: it belongs to the anatomical structure and is the basis of the occurrence of sputum. There are two cases of congenital and acquired. Congenital such as peritoneal sheath rupture, lower abdomen oblique muscle high, wide groin (Hesselbach) triangle, umbilical ring insufficiency, abdominal wall white line defect, etc., some normal anatomical phenomena, such as spermatic cord Or the uterine ligament through the inguinal canal, the femoral artery and vein through the femoral canal area, can also cause the abdominal wall strength to weaken. Acquired causes include surgical incision, poor healing of the drainage port, trauma, inflammation, infection, surgical cutting of the abdominal wall nerve, excessive fat infiltration in obese people, degeneration of muscles in old age, and abnormal metabolism of collagen, resulting in a firm fascia tissue. Anatomical reasons for the loosening of microporous connective tissue layers or fat.

2, increased internal pressure: is a predisposing factor, many reasons, such as chronic cough (such as smokers and bronchitis in the elderly), chronic constipation, late pregnancy, ascites, dysuria (prostatic hypertrophy, phimosis), babies often cry Weight lifting, frequent vomiting, and intra-abdominal tumors.

(two) pathogenesis

The pathological process of the white scorpion is divided into two stages, and its pathological characteristics are not the same.

The first stage: the sacral ligament, the round ligament and the surrounding fat tissue of the deep white line in the upper part of the abdomen are first protruded from the defect of the white line (ankle ring), and there is no peritoneal protrusion, so there is no sac and no visceral prolapse. Only the extraperitoneal fat protrudes from the ankle ring.

Stage 2: As the extra-peritoneal fat protrudes, the pores on the white line gradually expand. Under the action of intra-abdominal pressure, the extraperitoneal fat is protruded and the peritoneum covering the sacral ligament is pulled out to form the hernia sac, the internal organs (mainly The omentum is gradually released, so the white line at this stage has both a hernia sac and a visceral detachment. The contents protruding from the ankle ring include extraperitoneal fat protruding from the ankle sac and viscera excreted in the sac. The omentum protruding into the hernia sac may cause adhesion to the hernia sac, but incarceration rarely occurs.

Clinically, white sputum is usually divided into two types: sacral sac and sacral sac. It is actually two pathological stages in which the disease develops and develops, and most white mites remain in the previous stage, ie, no sputum Capsule type; only a few developed into a white-striped scorpion.

Examine

an examination

Related inspection

Abdominal perspective abdominal shape examination abdominal vascular ultrasound examination ascites examination ultrasound endoscopy

Clinical symptoms

Symptom

(1) Abdominal pain: The most common symptom of patients with white sputum is upper abdominal pain. Most patients showed only limited upper abdominal pain, while a few showed more severe deep pain. The mechanism of abdominal pain is mainly caused by the compression of the intercostal nerve fibers through the white line caused by the block, and the deep omentum and the round ligament of the liver cause deep pain. Abdominal pain can be radiated to the lower chest and back. The degree of pain is related to body position, eating and heavy physical labor, and the position changes, especially when lying down, the pain often decreases or disappears, and can be aggravated after eating or heavy physical labor. The severity of abdominal pain is not proportional to the size of the sputum, often small and clinically severe.

(2) nausea, vomiting: a small number of patients with white line phlegm, in addition to abdominal pain, may be accompanied by nausea, vomiting and other gastrointestinal symptoms. The mechanism of occurrence is:

1 The large omentum and the round ligament pulled out can cause deep pain and cause gastrointestinal symptoms such as reflex nausea and vomiting;

2 large omentum and round ligaments can lead to pyloric sputum, and then nausea, vomiting and other gastrointestinal symptoms.

2. Signs

(1) abdominal wall mass: abdominal wall mass is the main sign of white line mites. Since most of the white line lice occur between the umbilicus and the xiphoid process, the sputum block is mostly located on the white line between the xiphoid and the umbilicus on the umbilicus, which can be biased to the midline side, and the block is more obvious after standing or after meals. . The diameter of the sputum is generally about 2 to 4 cm. Some scholars have reported that the largest diameter of the sputum is 15 cm. A small number of patients have small sputum, but a soft round protrusion under the skin, which is difficult to detect, and obese patients are more difficult to find. When the contents of the sputum are returned, the edge of the fascial ankle ring hole can be touched at the white line.

(2) Litten sign positive: During the physical examination, put your finger on the suspected sputum, and cough when you are in the standing position. Sometimes, while coughing, the finger can feel the cracking sound, which means the Litten sign is positive.

(3) Induced pain: the thumb and the index finger are used to clamp the mass and pull outward. The abdominal pain is often induced by the round ligament, peritoneum or omentum. Moure et al consider that this is a specific clinical condition of the white sputum. Signs.

diagnosis

History

Generally, there are no special symptoms, and the patient reports self-reported abdominal pain, especially when the force is painful or aggravated, or the history of abdomen recanalization. Smaller white mites tend to be painful and easy to incarcerate.

2. Clinical features

A mass in the midline of the abdomen, when the supine rectus and rectus abdominis relax, the sacral block can return to the abdominal white line defect (ankle ring), the Litten sign is positive, and the thumb and the index finger are used to clamp the mass and pull outward to induce pain. Small and obese patients with prominent abdominal wall should be carefully examined to avoid missed diagnosis.

3. B-check.

Diagnosis

Differential diagnosis

Differential diagnosis of the mass at the midline of the abdomen:

1, abdomen "gas-like" mass: abdominal "gas-like" mass is a symptom of colon cancer. Colon cancer is more common in middle-aged and elderly people, and the majority of men aged 30-69 are more than women. Early symptoms are not obvious. Symptoms of common symptoms in the middle and late stage include abdominal pain and gastrointestinal irritation, abdominal mass, bowel habits and fecal trait changes, symptoms caused by anemia and chronic toxin absorption, and intestinal perforation.

2, the abdomen can touch a huge soft mass: the giant bladder - small colon - intestinal peristalsis syndrome patients are still normal weight at birth, later abdominal distension, no meconium, the abdomen can touch a huge soft mass, often susceptible to urinary Is an infection.

3, lower abdomen mass: lower abdomen mass refers to the lower abdomen has a lump, touch has a hard feeling, may be benign or malignant tumor, mostly for gynecological disease symptoms or intestinal, peritoneal diseases.

4, the right lower abdomen can touch the soft sausage-like mass: cecal granuloma with cecal amoebic granuloma and schistosomiasis granuloma. The cecal amoebic granuloma is a complication of chronic colitis caused by Entamaeba Histolytica. The ileocecal schistosomiasis granuloma is a late stage disease of intestinal schistosomiasis. The schistosomiasis egg deposition site is mainly the terminal ileum except the colon. The clinical symptoms are localized abdominal pain and intermittent diarrhea. The right lower abdomen can be touched with soft sausage-like mass. In addition, chronic low intestinal obstruction is often accompanied by acute intestinal obstruction.