Umbilical Endometriosis Presenting as Cyclical Umbilical Bleeding: A Case Report

A 43‐year‐old nulliparous woman presented with an 8‐month history of cyclical umbilical bleeding beginning on day two of her menses and resolving by the last day. This was accompanied by an umbilical swelling and colicky left lower abdominal pain. Her history included infertility and a diagnostic laparoscopy at a nearby facility, after which the symptoms began. She denied smoking, oral contraceptive use, prior abortions, and any family history of cancer or bleeding disorders. She was alert, hemodynamically stable, and in good nutritional status. BMI was 26.5 kg/m 2 . Abdominal examination revealed a 1 × 0.5 cm umbilical nodule associated with an umbilical hernia measuring 2 × 3 cm, with superficial blood clots. No organomegaly was noted. Other systemic examinations were unremarkable. Laboratory results showed: WBC 5.67 × 10 9 /L, hemoglobin 13 g/dL, platelets 220 × 10 9 /L, creatinine 64 μmol/L, urea 3.75 mmol/L, and normal electrolytes. Ultrasound revealed an isoechoic 1 × 1 cm umbilical lesion, an associated hernia, a bulky uterus with fibroids, and a functional right ovarian cyst. Biopsy revealed endometrioid‐like epithelium without atypia and stromal vascularity, confirming umbilical endometriosis (Figure  1 ). She was initially managed with a GnRH antagonist, followed by surgical treatment consisting of a myomectomy, excision of the umbilical lesion, and hernioplasty. She recovered uneventfully (Figure  2 ), remained symptom‐free for 6 months, and was referred back to gynecology for continued infertility management. Histopathology of cutaneous endometriosis demonstrating scattered endometrial glands (green arrow), endometrial stroma (yellow arrow), and subcutaneous fat (blue arrow) in the dermis, H&E staining at 20× original magnification (A); intermediate magnification of the endometrial glands and stroma, H&E staining at 40× original magnification (B). Immunohistochemistry demonstrating a positive staining of endometrial stromal cells by CD10 (C, D), and positive endometrial glands by estrogen receptor (C). Clinical post operatively photograph after 4 months with complete resolution of clinical symptoms.

Mujaheed Suleman: writing – original draft. Alex Mremi: formal analysis, resources. Bahati Robert Kitandu: methodology. Alice Mgaya: methodology. Gilbert Nkya: resources. Sayyida Suleman: investigation, methodology. Jay Lodhia: conceptualization, supervision, writing – review and editing.

Approval was obtained from the departments of General surgery and the appropriate hospital institutional review board has approved the publication of this case report.

The authors have nothing to report.

Primary umbilical endometriosis (Villar's nodule), first described in 1886, represents 0.5%–1% of extrapelvic endometriosis. Ectopic endometrial tissue has been reported in various sites, including the gastrointestinal tract, urinary system, lungs, and surgical scars [ 3 ]. Secondary umbilical endometriosis is most often linked to prior abdominal or gynecologic surgery, as in our patient's case. The accepted mechanism of endometriosis development is retrograde menstruation with peritoneal implantation, although alternative theories include stem cell origin, coelomic metaplasia, and genetic predisposition (alterations in p53, PTEN, CYP1A1, and PPAR‐γ2) [ 4 ]. Umbilical involvement may occur via lymphatic or hematogenous spread, metaplasia of urachal remnants, or direct surgical implantation [ 4 , 5 ]. Clinically, lesions measure 0.5–2.5 cm and may be bluish‐black, red‐brown, or skin‐colored depending on hemorrhagic content. Symptoms typically include cyclical pain, swelling, tenderness, bleeding, and hyperesthesia [ 6 , 7 ]. Differential diagnoses include granuloma, sebaceous cyst, keloid, umbilical hernia, urachal anomalies, and malignancies such as melanoma and Sister Mary Joseph nodule [ 8 ]. Ultrasound helps in assessing lesion size and involvement of surrounding tissues, though findings can be nonspecific. MRI, CT, and CA‐125 may assist but are not diagnostic [ 9 ]. Definitive diagnosis requires histology demonstrating at least two of the following: endometrial‐like glands, endometrial stroma, or hemosiderin‐laden macrophages [ 8 ]. Medical therapy (oral contraceptives, progestins, GnRH agonists/antagonists) may reduce symptoms but has high recurrence rates. Non‐radical approaches such as thermocoagulation are discouraged due to frequent relapse [ 10 ]. Surgical excision with adequate margins remains the gold standard and minimizes recurrence or rare malignant transformation [ 1 , 10 , 11 , 12 ]. Regional cases show good outcomes following surgical excision with postoperative follow‐up at 3–6 months to exclude recurrence [ 13 , 14 ]. Diagnostic laparoscopy may identify concurrent pelvic disease, but resource limitations in low‐income settings often preclude this [ 14 ]. Given rising infertility rates, secondary endometriosis should be considered in women with cyclical symptoms developing after gynecological or laparoscopic surgery.

Written informed consent was obtained from a legally authorized representative for publication of this case report; additionally, accompanying images have been censored to ensure patient confidentiality. A copy of the consent is available on record.

Endometriosis, first identified in 1860, is defined by the presence of functional endometrial tissue outside the uterine cavity. This benign, estrogen‐dependent condition affects 5%–10% of women [ 1 ] and is even more prevalent among those with chronic pelvic pain (71%–87%) or dysmenorrhea (up to 50%) [ 2 ]. While endometriosis predominantly involves pelvic structures, rare extrapelvic cases have been documented, including those affecting the umbilicus, thoracic cavity, and central nervous system. Secondary umbilical endometriosis most commonly results from iatrogenic implantation of endometrial tissue during gynecologic or laparoscopic procedures [ 1 ]. Here, we present a case of umbilical endometriosis in a 43‐year‐old woman following diagnostic laparoscopy.