Dermatology Online Journal

Atypical presentation of an omphalomesenteric duct cyst
Irene Ballester MD, Isabel Betlloch, María Pérez-Crespo, Fernando Toledo, Laura Cuesta
Dermatology Online Journal 15 (6): 13

Department of Dermatology. Hospital General Universitario, Alicante, Spain. ibalnor@coma.es

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Abstract

We describe a clinical case of an omphalomesenteric duct (OMD) cyst that presented as an umbilical nodule with a late and atypical clinical presentation. This report illustrates the possibility of OMD cyst resembling a keloid or dermatofibroma.

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Introduction

Anomalies associated with persistence of the omphalomesenteric duct (OMD) consist of a spectrum of lesions relating to total or partial lack of involvement of the OMD. We describe a clinical case of an omphalomesenteric duct cyst that presented as an umbilical nodule with a late and atypical clinical presentation.

Case report

Figure 1a	Figure 1b
Figure 1a. White umbilical nodule with smooth surface Figure 1b. Dermatoscopic image showing a fibrous central area surrounded by fine peripheral pigmentation.

A 2-year-old girl of Colombian parents born full term in Spain without complication, presented with an enlarging asymptomatic umbilical nodule that was first noticed at six months of age. The was no family history of any congenital anomaly. There had never been any bleeding or secretion, nor did it change when the patient cried. The umbilical cord had come off three weeks after birth and no local treatment had been applied.

On physical examination an umbilical nodule measuring 1 x 1 cm was found. It had a smooth surface, was bright white in color and firm on palpation (Fig. 1a). Dermatoscopically there was a fibrous central area surrounded by fine peripheral pigmentation, with no pigmentary reticulum or other signs of melanocytic lesion. The appearance of the nodule suggested it to be a scar or dermatofibroma (Fig. 1b). The rest of the physical examination was normal. Ultrasonography of the umbilical zone ruled out the presence of an omphalomesenteric or urachus duct. Excision of the fibrous nodule was performed. An associated small nodule that adhered to deep planes in the umbilical zone was also removed. Surgical examination was also performed to rule out the possibility of communication with the peritoneum.

Figure 2a	Figure 2b
Figure 2a. Histological image showing cystic dilatation with abundant mucoid material together with an intense fibrous reaction (H&E, x10) Figure 2b. Glandular acinis in the rest of the intestinal muscle wall (H&E, x20)

Histological examination of the excised umbilical nodule showed cystic dilatation with abundant mucoid material, together with an intense fibrous reaction. There was extravasation of mucus toward the dermis and inflammatory cell infiltrates (Fig. 2a) as well as glandular intestinal acinis in the rest of the intestinal muscle wall (Fig. 2b).

Given the diagnosis of an omphalomesenteric cyst, a technesium pertechnetate (Tc 99m) scan was perfomed and found to be negative. At present the patient is asymptomatic and only has a residual umbilical scar.

Discussion

The differential diagnosis of umbilical masses depends on the child's age [1]. In newborns the most frequent diagnosis is that of umbilical granuloma [2]. However, other diagnoses such as pyogenic umbilical granuloma, umbilical hernia, persistent urachus, omphalocele, and gastroquisis should also be considered.

The presence of an umbilical mass in children and adults is not common. In these situations the presence of a benign or malignant tumor should always be ruled out. Moreover, keloid or hypertrophic scarring may also resemble primary tumors. In our case, scarring on top of the cyst resembled a keloid or dermatofibroma.

The OMD connects the developing gastrointestinal tract to the yolk sac and normally completely regresses by the ninth week of gestation, leaving a fibrous cord. Failure to obliterate the omphalomesenteric duct may produce different malformations ranging from persistence of a fistula to incomplete closure of the duct, which gives rise to a polyp, cyst, or Merckel diverticulum (MD) depending on the portion that remains [3].

In addition, when there is a diagnosis of persistence of OMD it is always necessary to perform imaging tests with echography and/or Tc 99m scan [4, 5] in order to rule out the presence of more than one associated malformation, the most frequent of which is MD. Although most MD remain asymptomatic, about four to six percent may be symptomatic and cause obstruction, hemorrhage due to ulceration of the mucosa, or infections [6].

In conclusion, although persistence of OMD is usually diagnosed at an early age, this possibility should be considered when there is an umbilical tumor that resembles a scar. It could be an omphalomesenteric cyst associated with a fibrous reaction, as in our patient.

References

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3. Betlloch Mas I, Silvestre Salvador JF. Patología cutánea umbilical. Piel. 1996; 11: 341-53.

4. Vane DW, West KW, Grosfeld JL. Vitelline duct anomalies. Experience with 217 childhood cases. Arch surg 1987 May;122(5):542-7. [PubMed]

5. Levy AD, Hobbs CM. Merckel diverticulum: Radiologic Features with pathologic correlation. Radiographics 2004 Mar-Apr;24(2):565-87 6. [PubMed]

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