Differential Diagnosis, Investigation and Treatment

Abdominal ultrasonography showed an umbilical hernia containing mesenteric fat but no bowel loops, with a fascial defect measuring 20 mm. The lesion remained nonreducible despite gentle probe pressure. Dynamic assessment during the Valsalva maneuver demonstrated no reduction of the protruding tissue. Based on these findings, a provisional diagnosis of an irreducible umbilical hernia was made, prompting surgical exploration.

During surgery, an elliptical incision around the umbilicus allowed exposure of a firm, fibrotic, brownish mass measuring approximately 6.5 × 5 × 3.1 cm, adherent to the anterior rectus sheath (Figure 2). The discrepancy between the clinical and intraoperative measurements can be explained by the deeper extension of the lesion into the fascia, which was not fully appreciable on physical examination.

FIGURE 2: Intraoperative view of the umbilical lesion demonstrating deeper extension than initially appreciated on physical examination. The mass measured approximately 6.5 × 5 × 3.1 cm and was adherent to the anterior rectus sheath. The figure highlights the distinction between the superficial palpable component (S) and the deeper intraoperative extent (D).

The lesion, together with a rim of healthy surrounding tissue and the involved anterior rectus fascia, was completely excised (Figure 3). A total omphalectomy was performed due to the size of the lesion and fascial involvement. The fascial defect was repaired with absorbable sutures, and the abdominal wall was reconstructed to achieve an acceptable cosmetic contour. No peritoneal involvement or true hernia sac was identified intraoperatively.

FIGURE 3: Post‐excision specimen of the umbilical lesion after complete surgical removal, including a rim of surrounding fascia. Scale bar represents 1 cm. Complete excision was performed to ensure clear margins and reduce recurrence risk.

Histological examination of the excised tissue revealed irregular glandular structures embedded within a highly cellular and vascular stroma, morphologically consistent with functional endometrial tissue (Figure 4). These findings were characteristic of endometriosis. Immunohistochemical staining showed strong positivity for CD10 and estrogen receptor (ER), confirming the diagnosis of “umbilical endometriosis”; considering her history of two cesarean sections and the clinical presentation, this lesion was classified as secondary umbilical endometriosis.

FIGURE 4: Histopathological examination showing endometrial glands (G) and stroma (S) with hemorrhage (H). Hematoxylin and eosin (H&E) stain; magnification ×40. These features are characteristic of endometriosis.