An Atlas of Lumps and Bumps: Part 24

An umbilical hernia results from imperfect closure or weakness of the umbilical ring.^1,2 Umbilical hernias are found in 15% to 23% of newborn infants.³ The incidence is affected by gestational age, birth weight, age of the child, race, and coexisting disorders.⁴ Umbilical hernias are about six to 10 times more common in Black individuals than White individuals.^2,5 They are also more common in low-birth-weight and premature infants.⁵ The sex incidence is approximately equal.⁶

Most umbilical hernias are sporadic and occur as isolated findings in otherwise healthy infants. Umbilical hernias occur with increased frequency in patients with Beckwith-Wiedemann syndrome, Down syndrome, trisomy 13, trisomy 18, congenital hypothyroidism, mucopolysaccharidosis, and cirrhosis of the liver with ascites.^2,5

Classically, an umbilical hernia presents as a soft, skin-covered swelling that protrudes through the fibrous ring at the umbilicus.2 (Figure 1)

Figure 1 An umbilical hernia in an infant is shown.

The umbilical bulge becomes more apparent during episodes of crying, coughing, or straining and is easily capable of being reduced.² The content usually consists of a piece of small intestine and, sometimes, omentum. The condition is usually asymptomatic and recognized in the neonatal period.²  

Complications, such as incarceration of intestine or omentum, strangulation, perforation of the intestine, and rupture with evisceration, are rare in children.^1,2,6-8 The risk of complications varies greatly between populations worldwide and is much higher in adults.^7,9 For young women with persistent umbilical hernia, the umbilical defect may enlarge and become symptomatic during pregnancy.2 Most umbilical hernias resolve spontaneously, usually within the first 2 years of life, if not the first year.² Of the umbilical hernias not repaired in childhood, approximately 10% persist into adulthood.¹⁰

Paraumbilical Hernia

A paraumbilical hernia is due to a defect in the linea alba close to the umbilicus. Unlike an umbilical hernia, a paraumbilical hernia does not protrude through the umbilical area. Rather, it protrudes just above or below the umbilicus (Figure 2). Unless complicated, a paraumbilical hernia can be reduced manually  and asymptomatic.

Figure 2. A paraumbilical hernia in an adult male is shown.

Although the defect in the linea alba is congenital, a paraumbilical hernia may not be noticeable until later in life when abdominal contents herniate through the defect and presents with a visible lump on the abdominal wall. Paraumbilical hernias are more common in adults than in children.

The female to male ratio is about 5:1.¹¹ The condition is more common in White individuals, those with obesity, and in those with weak abdominal muscles.12 A paraumbilical hernia poses a risk of incarceration and strangulation.^13-15 Omentum, small bowel, and large bowel are the usual content.¹¹ Occasionally, the content consists of an appendix or a Meckel’s diverticulum.^15,16

The diagnosis of paraumbilical hernia can usually be made clinically unless the hernia sac is small or the patient’s body habitus interferes with adequate palpation. High-resolution ultrasonography is an efficient tool for detecting the presence of a paraumbilical hernia and accurately verifies not only its content but also possible associated complications.¹³ A recent onset of a paraumbilical hernia in the elderly is a possible sign of internal malignancy.¹⁷

A paraumbilical hernia does not close spontaneously.¹² Elective herniorrhaphy is advisable because of the recognized risk of complications.

CITATION:
Leung AKC, Barankin B, Lam JM, Leung AAH, Wong AHC. An atlas of lumps and bumps, part 24. Consultant. 2023;63(2):e11. DOI: 10.25270/con.2023.02.000002.

DISCLOSURES:
Dr Leung is the series editor. He was not involved with the handling of this paper, which was sent out for independent external peer review.

CORRESPONDENCE:
Alexander K. C. Leung, MD, #200, 233 16th Ave NW, Calgary, AB T2M 0H5, Canada (aleung@ucalgary.ca)

EDITOR’S NOTE:
This article is part of a series describing and differentiating dermatologic lumps and bumps. To access previously published articles in the series, visit https://www.consultant360.com/resource-center/atlas-lumps-and-bumps.